diff --git a/cartographer/internal/mapping_2d/local_trajectory_builder_2d.cc b/cartographer/internal/mapping/2d/local_trajectory_builder_2d.cc
similarity index 99%
rename from cartographer/internal/mapping_2d/local_trajectory_builder_2d.cc
rename to cartographer/internal/mapping/2d/local_trajectory_builder_2d.cc
index a04782b..6860e47 100644
--- a/cartographer/internal/mapping_2d/local_trajectory_builder_2d.cc
+++ b/cartographer/internal/mapping/2d/local_trajectory_builder_2d.cc
@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-#include "cartographer/internal/mapping_2d/local_trajectory_builder_2d.h"
+#include "cartographer/internal/mapping/2d/local_trajectory_builder_2d.h"
 
 #include <limits>
 #include <memory>
diff --git a/cartographer/internal/mapping_2d/local_trajectory_builder_2d.h b/cartographer/internal/mapping/2d/local_trajectory_builder_2d.h
similarity index 94%
rename from cartographer/internal/mapping_2d/local_trajectory_builder_2d.h
rename to cartographer/internal/mapping/2d/local_trajectory_builder_2d.h
index 2f9c61f..2af72ec 100644
--- a/cartographer/internal/mapping_2d/local_trajectory_builder_2d.h
+++ b/cartographer/internal/mapping/2d/local_trajectory_builder_2d.h
@@ -21,11 +21,11 @@
 
 #include "cartographer/common/time.h"
 #include "cartographer/internal/mapping/motion_filter.h"
+#include "cartographer/mapping/2d/proto/local_trajectory_builder_options_2d.pb.h"
+#include "cartographer/mapping/2d/scan_matching/ceres_scan_matcher_2d.h"
+#include "cartographer/mapping/2d/scan_matching/real_time_correlative_scan_matcher_2d.h"
+#include "cartographer/mapping/2d/submap_2d.h"
 #include "cartographer/mapping/pose_extrapolator.h"
-#include "cartographer/mapping_2d/proto/local_trajectory_builder_options_2d.pb.h"
-#include "cartographer/mapping_2d/scan_matching/ceres_scan_matcher_2d.h"
-#include "cartographer/mapping_2d/scan_matching/real_time_correlative_scan_matcher_2d.h"
-#include "cartographer/mapping_2d/submap_2d.h"
 #include "cartographer/sensor/imu_data.h"
 #include "cartographer/sensor/odometry_data.h"
 #include "cartographer/sensor/range_data.h"
diff --git a/cartographer/internal/mapping_2d/scan_matching/occupied_space_cost_function_2d.h b/cartographer/internal/mapping/2d/scan_matching/occupied_space_cost_function_2d.h
similarity index 98%
rename from cartographer/internal/mapping_2d/scan_matching/occupied_space_cost_function_2d.h
rename to cartographer/internal/mapping/2d/scan_matching/occupied_space_cost_function_2d.h
index 2a13985..0f6836b 100644
--- a/cartographer/internal/mapping_2d/scan_matching/occupied_space_cost_function_2d.h
+++ b/cartographer/internal/mapping/2d/scan_matching/occupied_space_cost_function_2d.h
@@ -19,8 +19,8 @@
 
 #include "Eigen/Core"
 #include "Eigen/Geometry"
+#include "cartographer/mapping/2d/probability_grid.h"
 #include "cartographer/mapping/probability_values.h"
-#include "cartographer/mapping_2d/probability_grid.h"
 #include "cartographer/sensor/point_cloud.h"
 #include "ceres/ceres.h"
 #include "ceres/cubic_interpolation.h"
diff --git a/cartographer/internal/mapping_3d/acceleration_cost_function_3d.h b/cartographer/internal/mapping/3d/acceleration_cost_function_3d.h
similarity index 100%
rename from cartographer/internal/mapping_3d/acceleration_cost_function_3d.h
rename to cartographer/internal/mapping/3d/acceleration_cost_function_3d.h
diff --git a/cartographer/internal/mapping_3d/local_trajectory_builder_3d.cc b/cartographer/internal/mapping/3d/local_trajectory_builder_3d.cc
similarity index 97%
rename from cartographer/internal/mapping_3d/local_trajectory_builder_3d.cc
rename to cartographer/internal/mapping/3d/local_trajectory_builder_3d.cc
index a1bbe5f..b3e0bdb 100644
--- a/cartographer/internal/mapping_3d/local_trajectory_builder_3d.cc
+++ b/cartographer/internal/mapping/3d/local_trajectory_builder_3d.cc
@@ -14,17 +14,17 @@
  * limitations under the License.
  */
 
-#include "cartographer/internal/mapping_3d/local_trajectory_builder_3d.h"
+#include "cartographer/internal/mapping/3d/local_trajectory_builder_3d.h"
 
 #include <memory>
 
 #include "cartographer/common/make_unique.h"
 #include "cartographer/common/time.h"
+#include "cartographer/mapping/3d/proto/local_trajectory_builder_options_3d.pb.h"
+#include "cartographer/mapping/3d/proto/submaps_options_3d.pb.h"
+#include "cartographer/mapping/3d/scan_matching/proto/ceres_scan_matcher_options_3d.pb.h"
+#include "cartographer/mapping/3d/scan_matching/rotational_scan_matcher.h"
 #include "cartographer/mapping/scan_matching/proto/real_time_correlative_scan_matcher_options.pb.h"
-#include "cartographer/mapping_3d/proto/local_trajectory_builder_options_3d.pb.h"
-#include "cartographer/mapping_3d/proto/submaps_options_3d.pb.h"
-#include "cartographer/mapping_3d/scan_matching/proto/ceres_scan_matcher_options_3d.pb.h"
-#include "cartographer/mapping_3d/scan_matching/rotational_scan_matcher.h"
 #include "glog/logging.h"
 
 namespace cartographer {
diff --git a/cartographer/internal/mapping_3d/local_trajectory_builder_3d.h b/cartographer/internal/mapping/3d/local_trajectory_builder_3d.h
similarity index 94%
rename from cartographer/internal/mapping_3d/local_trajectory_builder_3d.h
rename to cartographer/internal/mapping/3d/local_trajectory_builder_3d.h
index 7f2d456..11be07f 100644
--- a/cartographer/internal/mapping_3d/local_trajectory_builder_3d.h
+++ b/cartographer/internal/mapping/3d/local_trajectory_builder_3d.h
@@ -21,11 +21,11 @@
 
 #include "cartographer/common/time.h"
 #include "cartographer/internal/mapping/motion_filter.h"
+#include "cartographer/mapping/3d/proto/local_trajectory_builder_options_3d.pb.h"
+#include "cartographer/mapping/3d/scan_matching/ceres_scan_matcher_3d.h"
+#include "cartographer/mapping/3d/scan_matching/real_time_correlative_scan_matcher_3d.h"
+#include "cartographer/mapping/3d/submap_3d.h"
 #include "cartographer/mapping/pose_extrapolator.h"
-#include "cartographer/mapping_3d/proto/local_trajectory_builder_options_3d.pb.h"
-#include "cartographer/mapping_3d/scan_matching/ceres_scan_matcher_3d.h"
-#include "cartographer/mapping_3d/scan_matching/real_time_correlative_scan_matcher_3d.h"
-#include "cartographer/mapping_3d/submap_3d.h"
 #include "cartographer/sensor/imu_data.h"
 #include "cartographer/sensor/odometry_data.h"
 #include "cartographer/sensor/range_data.h"
diff --git a/cartographer/internal/mapping_3d/local_trajectory_builder_3d_test.cc b/cartographer/internal/mapping/3d/local_trajectory_builder_3d_test.cc
similarity index 98%
rename from cartographer/internal/mapping_3d/local_trajectory_builder_3d_test.cc
rename to cartographer/internal/mapping/3d/local_trajectory_builder_3d_test.cc
index ba8bf8a..2572e86 100644
--- a/cartographer/internal/mapping_3d/local_trajectory_builder_3d_test.cc
+++ b/cartographer/internal/mapping/3d/local_trajectory_builder_3d_test.cc
@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-#include "cartographer/internal/mapping_3d/local_trajectory_builder_3d.h"
+#include "cartographer/internal/mapping/3d/local_trajectory_builder_3d.h"
 
 #include <memory>
 #include <random>
@@ -22,8 +22,8 @@
 #include "Eigen/Core"
 #include "cartographer/common/lua_parameter_dictionary_test_helpers.h"
 #include "cartographer/common/time.h"
-#include "cartographer/mapping_3d/hybrid_grid.h"
-#include "cartographer/mapping_3d/local_trajectory_builder_options_3d.h"
+#include "cartographer/mapping/3d/hybrid_grid.h"
+#include "cartographer/mapping/3d/local_trajectory_builder_options_3d.h"
 #include "cartographer/sensor/range_data.h"
 #include "cartographer/transform/rigid_transform.h"
 #include "cartographer/transform/rigid_transform_test_helpers.h"
diff --git a/cartographer/internal/mapping_3d/rotation_cost_function_3d.h b/cartographer/internal/mapping/3d/rotation_cost_function_3d.h
similarity index 100%
rename from cartographer/internal/mapping_3d/rotation_cost_function_3d.h
rename to cartographer/internal/mapping/3d/rotation_cost_function_3d.h
diff --git a/cartographer/internal/mapping_3d/scan_matching/occupied_space_cost_function_3d.h b/cartographer/internal/mapping/3d/scan_matching/occupied_space_cost_function_3d.h
similarity index 96%
rename from cartographer/internal/mapping_3d/scan_matching/occupied_space_cost_function_3d.h
rename to cartographer/internal/mapping/3d/scan_matching/occupied_space_cost_function_3d.h
index b32db99..52badba 100644
--- a/cartographer/internal/mapping_3d/scan_matching/occupied_space_cost_function_3d.h
+++ b/cartographer/internal/mapping/3d/scan_matching/occupied_space_cost_function_3d.h
@@ -18,8 +18,8 @@
 #define CARTOGRAPHER_INTERNAL_MAPPING_3D_SCAN_MATCHING_OCCUPIED_SPACE_COST_FUNCTION_3D_H_
 
 #include "Eigen/Core"
-#include "cartographer/mapping_3d/hybrid_grid.h"
-#include "cartographer/mapping_3d/scan_matching/interpolated_grid.h"
+#include "cartographer/mapping/3d/hybrid_grid.h"
+#include "cartographer/mapping/3d/scan_matching/interpolated_grid.h"
 #include "cartographer/sensor/point_cloud.h"
 #include "cartographer/transform/rigid_transform.h"
 #include "cartographer/transform/transform.h"
diff --git a/cartographer/internal/mapping/global_trajectory_builder.h b/cartographer/internal/mapping/global_trajectory_builder.h
index 8d24dd3..39b7e43 100644
--- a/cartographer/internal/mapping/global_trajectory_builder.h
+++ b/cartographer/internal/mapping/global_trajectory_builder.h
@@ -19,12 +19,12 @@
 
 #include <memory>
 
-#include "cartographer/internal/mapping_2d/local_trajectory_builder_2d.h"
-#include "cartographer/internal/mapping_3d/local_trajectory_builder_3d.h"
+#include "cartographer/internal/mapping/2d/local_trajectory_builder_2d.h"
+#include "cartographer/internal/mapping/3d/local_trajectory_builder_3d.h"
+#include "cartographer/mapping/2d/pose_graph_2d.h"
+#include "cartographer/mapping/3d/pose_graph_3d.h"
 #include "cartographer/mapping/local_slam_result_data.h"
 #include "cartographer/mapping/trajectory_builder_interface.h"
-#include "cartographer/mapping_2d/pose_graph_2d.h"
-#include "cartographer/mapping_3d/pose_graph_3d.h"
 
 namespace cartographer {
 namespace mapping {
diff --git a/cartographer/io/hybrid_grid_points_processor.cc b/cartographer/io/hybrid_grid_points_processor.cc
index 308fc5f..e998e23 100644
--- a/cartographer/io/hybrid_grid_points_processor.cc
+++ b/cartographer/io/hybrid_grid_points_processor.cc
@@ -8,8 +8,8 @@
 #include "cartographer/io/file_writer.h"
 #include "cartographer/io/points_batch.h"
 #include "cartographer/io/points_processor.h"
-#include "cartographer/mapping_3d/hybrid_grid.h"
-#include "cartographer/mapping_3d/range_data_inserter_3d.h"
+#include "cartographer/mapping/3d/hybrid_grid.h"
+#include "cartographer/mapping/3d/range_data_inserter_3d.h"
 #include "cartographer/sensor/range_data.h"
 #include "glog/logging.h"
 
diff --git a/cartographer/io/hybrid_grid_points_processor.h b/cartographer/io/hybrid_grid_points_processor.h
index 451c948..1d80655 100644
--- a/cartographer/io/hybrid_grid_points_processor.h
+++ b/cartographer/io/hybrid_grid_points_processor.h
@@ -9,9 +9,9 @@
 #include "cartographer/io/file_writer.h"
 #include "cartographer/io/points_batch.h"
 #include "cartographer/io/points_processor.h"
-#include "cartographer/mapping_3d/hybrid_grid.h"
-#include "cartographer/mapping_3d/proto/range_data_inserter_options_3d.pb.h"
-#include "cartographer/mapping_3d/range_data_inserter_3d.h"
+#include "cartographer/mapping/3d/hybrid_grid.h"
+#include "cartographer/mapping/3d/proto/range_data_inserter_options_3d.pb.h"
+#include "cartographer/mapping/3d/range_data_inserter_3d.h"
 
 namespace cartographer {
 namespace io {
diff --git a/cartographer/io/outlier_removing_points_processor.h b/cartographer/io/outlier_removing_points_processor.h
index 60ed6d7..fefc828 100644
--- a/cartographer/io/outlier_removing_points_processor.h
+++ b/cartographer/io/outlier_removing_points_processor.h
@@ -19,7 +19,7 @@
 
 #include "cartographer/common/lua_parameter_dictionary.h"
 #include "cartographer/io/points_processor.h"
-#include "cartographer/mapping_3d/hybrid_grid.h"
+#include "cartographer/mapping/3d/hybrid_grid.h"
 
 namespace cartographer {
 namespace io {
diff --git a/cartographer/io/probability_grid_points_processor.h b/cartographer/io/probability_grid_points_processor.h
index fac51b3..3c0cd53 100644
--- a/cartographer/io/probability_grid_points_processor.h
+++ b/cartographer/io/probability_grid_points_processor.h
@@ -23,10 +23,10 @@
 #include "cartographer/io/image.h"
 #include "cartographer/io/points_batch.h"
 #include "cartographer/io/points_processor.h"
+#include "cartographer/mapping/2d/probability_grid.h"
+#include "cartographer/mapping/2d/proto/range_data_inserter_options_2d.pb.h"
+#include "cartographer/mapping/2d/range_data_inserter_2d.h"
 #include "cartographer/mapping/proto/trajectory.pb.h"
-#include "cartographer/mapping_2d/probability_grid.h"
-#include "cartographer/mapping_2d/proto/range_data_inserter_options_2d.pb.h"
-#include "cartographer/mapping_2d/range_data_inserter_2d.h"
 
 namespace cartographer {
 namespace io {
diff --git a/cartographer/io/submap_painter.cc b/cartographer/io/submap_painter.cc
index 8feee2f..1c5855c 100644
--- a/cartographer/io/submap_painter.cc
+++ b/cartographer/io/submap_painter.cc
@@ -16,8 +16,8 @@
 
 #include "cartographer/io/submap_painter.h"
 
-#include "cartographer/mapping_2d/submap_2d.h"
-#include "cartographer/mapping_3d/submap_3d.h"
+#include "cartographer/mapping/2d/submap_2d.h"
+#include "cartographer/mapping/3d/submap_3d.h"
 
 namespace cartographer {
 namespace io {
diff --git a/cartographer/io/xray_points_processor.cc b/cartographer/io/xray_points_processor.cc
index 08827d5..6c9b090 100644
--- a/cartographer/io/xray_points_processor.cc
+++ b/cartographer/io/xray_points_processor.cc
@@ -25,8 +25,8 @@
 #include "cartographer/common/math.h"
 #include "cartographer/io/draw_trajectories.h"
 #include "cartographer/io/image.h"
+#include "cartographer/mapping/3d/hybrid_grid.h"
 #include "cartographer/mapping/detect_floors.h"
-#include "cartographer/mapping_3d/hybrid_grid.h"
 #include "cartographer/transform/transform.h"
 
 namespace cartographer {
diff --git a/cartographer/io/xray_points_processor.h b/cartographer/io/xray_points_processor.h
index 5029718..1d269a8 100644
--- a/cartographer/io/xray_points_processor.h
+++ b/cartographer/io/xray_points_processor.h
@@ -23,9 +23,9 @@
 #include "cartographer/common/lua_parameter_dictionary.h"
 #include "cartographer/io/file_writer.h"
 #include "cartographer/io/points_processor.h"
+#include "cartographer/mapping/3d/hybrid_grid.h"
 #include "cartographer/mapping/detect_floors.h"
 #include "cartographer/mapping/proto/trajectory.pb.h"
-#include "cartographer/mapping_3d/hybrid_grid.h"
 #include "cartographer/transform/rigid_transform.h"
 
 namespace cartographer {
diff --git a/cartographer/mapping_2d/local_trajectory_builder_options_2d.cc b/cartographer/mapping/2d/local_trajectory_builder_options_2d.cc
similarity index 92%
rename from cartographer/mapping_2d/local_trajectory_builder_options_2d.cc
rename to cartographer/mapping/2d/local_trajectory_builder_options_2d.cc
index e64c7c0..6ec6f6e 100644
--- a/cartographer/mapping_2d/local_trajectory_builder_options_2d.cc
+++ b/cartographer/mapping/2d/local_trajectory_builder_options_2d.cc
@@ -14,12 +14,12 @@
  * limitations under the License.
  */
 
-#include "cartographer/mapping_2d/local_trajectory_builder_options_2d.h"
+#include "cartographer/mapping/2d/local_trajectory_builder_options_2d.h"
 
 #include "cartographer/internal/mapping/motion_filter.h"
-#include "cartographer/mapping_2d/scan_matching/ceres_scan_matcher_2d.h"
-#include "cartographer/mapping_2d/scan_matching/real_time_correlative_scan_matcher_2d.h"
-#include "cartographer/mapping_2d/submap_2d.h"
+#include "cartographer/mapping/2d/scan_matching/ceres_scan_matcher_2d.h"
+#include "cartographer/mapping/2d/scan_matching/real_time_correlative_scan_matcher_2d.h"
+#include "cartographer/mapping/2d/submap_2d.h"
 #include "cartographer/sensor/voxel_filter.h"
 
 namespace cartographer {
diff --git a/cartographer/mapping_2d/local_trajectory_builder_options_2d.h b/cartographer/mapping/2d/local_trajectory_builder_options_2d.h
similarity index 94%
rename from cartographer/mapping_2d/local_trajectory_builder_options_2d.h
rename to cartographer/mapping/2d/local_trajectory_builder_options_2d.h
index 68d0f4a..d66337e 100644
--- a/cartographer/mapping_2d/local_trajectory_builder_options_2d.h
+++ b/cartographer/mapping/2d/local_trajectory_builder_options_2d.h
@@ -18,7 +18,7 @@
 #define CARTOGRAPHER_MAPPING_2D_LOCAL_TRAJECTORY_BUILDER_OPTIONS_2D_H_
 
 #include "cartographer/common/lua_parameter_dictionary.h"
-#include "cartographer/mapping_2d/proto/local_trajectory_builder_options_2d.pb.h"
+#include "cartographer/mapping/2d/proto/local_trajectory_builder_options_2d.pb.h"
 
 namespace cartographer {
 namespace mapping {
diff --git a/cartographer/mapping_2d/map_limits.h b/cartographer/mapping/2d/map_limits.h
similarity index 97%
rename from cartographer/mapping_2d/map_limits.h
rename to cartographer/mapping/2d/map_limits.h
index a91fa06..d131bcb 100644
--- a/cartographer/mapping_2d/map_limits.h
+++ b/cartographer/mapping/2d/map_limits.h
@@ -23,9 +23,9 @@
 #include "Eigen/Core"
 #include "Eigen/Geometry"
 #include "cartographer/common/math.h"
+#include "cartographer/mapping/2d/proto/map_limits.pb.h"
+#include "cartographer/mapping/2d/xy_index.h"
 #include "cartographer/mapping/trajectory_node.h"
-#include "cartographer/mapping_2d/proto/map_limits.pb.h"
-#include "cartographer/mapping_2d/xy_index.h"
 #include "cartographer/sensor/point_cloud.h"
 #include "cartographer/sensor/range_data.h"
 #include "cartographer/transform/rigid_transform.h"
diff --git a/cartographer/mapping_2d/map_limits_test.cc b/cartographer/mapping/2d/map_limits_test.cc
similarity index 97%
rename from cartographer/mapping_2d/map_limits_test.cc
rename to cartographer/mapping/2d/map_limits_test.cc
index c3a414e..ee54164 100644
--- a/cartographer/mapping_2d/map_limits_test.cc
+++ b/cartographer/mapping/2d/map_limits_test.cc
@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-#include "cartographer/mapping_2d/map_limits.h"
+#include "cartographer/mapping/2d/map_limits.h"
 
 #include "gtest/gtest.h"
 
diff --git a/cartographer/mapping_2d/pose_graph/constraint_builder_2d.cc b/cartographer/mapping/2d/pose_graph/constraint_builder_2d.cc
similarity index 97%
rename from cartographer/mapping_2d/pose_graph/constraint_builder_2d.cc
rename to cartographer/mapping/2d/pose_graph/constraint_builder_2d.cc
index d6e1857..3ce1631 100644
--- a/cartographer/mapping_2d/pose_graph/constraint_builder_2d.cc
+++ b/cartographer/mapping/2d/pose_graph/constraint_builder_2d.cc
@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-#include "cartographer/mapping_2d/pose_graph/constraint_builder_2d.h"
+#include "cartographer/mapping/2d/pose_graph/constraint_builder_2d.h"
 
 #include <cmath>
 #include <functional>
@@ -29,8 +29,8 @@
 #include "cartographer/common/make_unique.h"
 #include "cartographer/common/math.h"
 #include "cartographer/common/thread_pool.h"
-#include "cartographer/mapping_2d/scan_matching/proto/ceres_scan_matcher_options_2d.pb.h"
-#include "cartographer/mapping_2d/scan_matching/proto/fast_correlative_scan_matcher_options_2d.pb.h"
+#include "cartographer/mapping/2d/scan_matching/proto/ceres_scan_matcher_options_2d.pb.h"
+#include "cartographer/mapping/2d/scan_matching/proto/fast_correlative_scan_matcher_options_2d.pb.h"
 #include "cartographer/metrics/counter.h"
 #include "cartographer/metrics/gauge.h"
 #include "cartographer/metrics/histogram.h"
@@ -307,7 +307,7 @@ void ConstraintBuilder2D::DeleteScanMatcher(const SubmapId& submap_id) {
 
 void ConstraintBuilder2D::RegisterMetrics(metrics::FamilyFactory* factory) {
   auto* counts = factory->NewCounterFamily(
-      "/mapping_2d/pose_graph/constraint_builder/constraints",
+      "/mapping/2d/pose_graph/constraint_builder/constraints",
       "Constraints computed");
   kConstraintsSearchedMetric =
       counts->Add({{"search_region", "local"}, {"matcher", "searched"}});
@@ -318,11 +318,11 @@ void ConstraintBuilder2D::RegisterMetrics(metrics::FamilyFactory* factory) {
   kGlobalConstraintsFoundMetric =
       counts->Add({{"search_region", "global"}, {"matcher", "found"}});
   auto* queue_length = factory->NewGaugeFamily(
-      "/mapping_2d/pose_graph/constraint_builder/queue_length", "Queue length");
+      "/mapping/2d/pose_graph/constraint_builder/queue_length", "Queue length");
   kQueueLengthMetric = queue_length->Add({{}});
   auto boundaries = metrics::Histogram::FixedWidth(0.05, 20);
   auto* scores = factory->NewHistogramFamily(
-      "/mapping_2d/pose_graph/constraint_builder/scores",
+      "/mapping/2d/pose_graph/constraint_builder/scores",
       "Constraint scores built", boundaries);
   kConstraintScoresMetric = scores->Add({{"search_region", "local"}});
   kGlobalConstraintScoresMetric = scores->Add({{"search_region", "global"}});
diff --git a/cartographer/mapping_2d/pose_graph/constraint_builder_2d.h b/cartographer/mapping/2d/pose_graph/constraint_builder_2d.h
similarity index 97%
rename from cartographer/mapping_2d/pose_graph/constraint_builder_2d.h
rename to cartographer/mapping/2d/pose_graph/constraint_builder_2d.h
index 93b0254..c671be1 100644
--- a/cartographer/mapping_2d/pose_graph/constraint_builder_2d.h
+++ b/cartographer/mapping/2d/pose_graph/constraint_builder_2d.h
@@ -30,11 +30,11 @@
 #include "cartographer/common/math.h"
 #include "cartographer/common/mutex.h"
 #include "cartographer/common/thread_pool.h"
+#include "cartographer/mapping/2d/scan_matching/ceres_scan_matcher_2d.h"
+#include "cartographer/mapping/2d/scan_matching/fast_correlative_scan_matcher_2d.h"
+#include "cartographer/mapping/2d/submap_2d.h"
 #include "cartographer/mapping/pose_graph/proto/constraint_builder_options.pb.h"
 #include "cartographer/mapping/pose_graph_interface.h"
-#include "cartographer/mapping_2d/scan_matching/ceres_scan_matcher_2d.h"
-#include "cartographer/mapping_2d/scan_matching/fast_correlative_scan_matcher_2d.h"
-#include "cartographer/mapping_2d/submap_2d.h"
 #include "cartographer/metrics/family_factory.h"
 #include "cartographer/sensor/point_cloud.h"
 #include "cartographer/sensor/voxel_filter.h"
diff --git a/cartographer/mapping_2d/pose_graph/landmark_cost_function_2d.h b/cartographer/mapping/2d/pose_graph/landmark_cost_function_2d.h
similarity index 98%
rename from cartographer/mapping_2d/pose_graph/landmark_cost_function_2d.h
rename to cartographer/mapping/2d/pose_graph/landmark_cost_function_2d.h
index 98dd7d2..17d6966 100644
--- a/cartographer/mapping_2d/pose_graph/landmark_cost_function_2d.h
+++ b/cartographer/mapping/2d/pose_graph/landmark_cost_function_2d.h
@@ -19,9 +19,9 @@
 
 #include "Eigen/Core"
 #include "Eigen/Geometry"
+#include "cartographer/mapping/2d/pose_graph/optimization_problem_2d.h"
 #include "cartographer/mapping/pose_graph/cost_helpers.h"
 #include "cartographer/mapping/pose_graph_interface.h"
-#include "cartographer/mapping_2d/pose_graph/optimization_problem_2d.h"
 #include "cartographer/transform/rigid_transform.h"
 #include "cartographer/transform/transform.h"
 #include "ceres/ceres.h"
diff --git a/cartographer/mapping_2d/pose_graph/landmark_cost_function_2d_test.cc b/cartographer/mapping/2d/pose_graph/landmark_cost_function_2d_test.cc
similarity index 97%
rename from cartographer/mapping_2d/pose_graph/landmark_cost_function_2d_test.cc
rename to cartographer/mapping/2d/pose_graph/landmark_cost_function_2d_test.cc
index 8d3220d..123e4c9 100644
--- a/cartographer/mapping_2d/pose_graph/landmark_cost_function_2d_test.cc
+++ b/cartographer/mapping/2d/pose_graph/landmark_cost_function_2d_test.cc
@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-#include "cartographer/mapping_2d/pose_graph/landmark_cost_function_2d.h"
+#include "cartographer/mapping/2d/pose_graph/landmark_cost_function_2d.h"
 
 #include <memory>
 
diff --git a/cartographer/mapping_2d/pose_graph/optimization_problem_2d.cc b/cartographer/mapping/2d/pose_graph/optimization_problem_2d.cc
similarity index 98%
rename from cartographer/mapping_2d/pose_graph/optimization_problem_2d.cc
rename to cartographer/mapping/2d/pose_graph/optimization_problem_2d.cc
index b6792eb..4b5b72b 100644
--- a/cartographer/mapping_2d/pose_graph/optimization_problem_2d.cc
+++ b/cartographer/mapping/2d/pose_graph/optimization_problem_2d.cc
@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-#include "cartographer/mapping_2d/pose_graph/optimization_problem_2d.h"
+#include "cartographer/mapping/2d/pose_graph/optimization_problem_2d.h"
 
 #include <algorithm>
 #include <array>
@@ -27,9 +27,9 @@
 #include "cartographer/common/ceres_solver_options.h"
 #include "cartographer/common/histogram.h"
 #include "cartographer/common/math.h"
+#include "cartographer/mapping/2d/pose_graph/landmark_cost_function_2d.h"
+#include "cartographer/mapping/2d/pose_graph/spa_cost_function_2d.h"
 #include "cartographer/mapping/pose_graph/ceres_pose.h"
-#include "cartographer/mapping_2d/pose_graph/landmark_cost_function_2d.h"
-#include "cartographer/mapping_2d/pose_graph/spa_cost_function_2d.h"
 #include "cartographer/sensor/odometry_data.h"
 #include "cartographer/transform/transform.h"
 #include "ceres/ceres.h"
diff --git a/cartographer/mapping_2d/pose_graph/optimization_problem_2d.h b/cartographer/mapping/2d/pose_graph/optimization_problem_2d.h
similarity index 100%
rename from cartographer/mapping_2d/pose_graph/optimization_problem_2d.h
rename to cartographer/mapping/2d/pose_graph/optimization_problem_2d.h
diff --git a/cartographer/mapping_2d/pose_graph/spa_cost_function_2d.h b/cartographer/mapping/2d/pose_graph/spa_cost_function_2d.h
similarity index 100%
rename from cartographer/mapping_2d/pose_graph/spa_cost_function_2d.h
rename to cartographer/mapping/2d/pose_graph/spa_cost_function_2d.h
diff --git a/cartographer/mapping_2d/pose_graph_2d.cc b/cartographer/mapping/2d/pose_graph_2d.cc
similarity index 99%
rename from cartographer/mapping_2d/pose_graph_2d.cc
rename to cartographer/mapping/2d/pose_graph_2d.cc
index 053825f..ccecb32 100644
--- a/cartographer/mapping_2d/pose_graph_2d.cc
+++ b/cartographer/mapping/2d/pose_graph_2d.cc
@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-#include "cartographer/mapping_2d/pose_graph_2d.h"
+#include "cartographer/mapping/2d/pose_graph_2d.h"
 
 #include <algorithm>
 #include <cmath>
diff --git a/cartographer/mapping_2d/pose_graph_2d.h b/cartographer/mapping/2d/pose_graph_2d.h
similarity index 98%
rename from cartographer/mapping_2d/pose_graph_2d.h
rename to cartographer/mapping/2d/pose_graph_2d.h
index 92d30d6..a6230e5 100644
--- a/cartographer/mapping_2d/pose_graph_2d.h
+++ b/cartographer/mapping/2d/pose_graph_2d.h
@@ -32,12 +32,12 @@
 #include "cartographer/common/mutex.h"
 #include "cartographer/common/thread_pool.h"
 #include "cartographer/common/time.h"
+#include "cartographer/mapping/2d/pose_graph/constraint_builder_2d.h"
+#include "cartographer/mapping/2d/pose_graph/optimization_problem_2d.h"
+#include "cartographer/mapping/2d/submap_2d.h"
 #include "cartographer/mapping/pose_graph.h"
 #include "cartographer/mapping/pose_graph_trimmer.h"
 #include "cartographer/mapping/trajectory_connectivity_state.h"
-#include "cartographer/mapping_2d/pose_graph/constraint_builder_2d.h"
-#include "cartographer/mapping_2d/pose_graph/optimization_problem_2d.h"
-#include "cartographer/mapping_2d/submap_2d.h"
 #include "cartographer/sensor/fixed_frame_pose_data.h"
 #include "cartographer/sensor/landmark_data.h"
 #include "cartographer/sensor/odometry_data.h"
diff --git a/cartographer/mapping_2d/pose_graph_2d_test.cc b/cartographer/mapping/2d/pose_graph_2d_test.cc
similarity index 98%
rename from cartographer/mapping_2d/pose_graph_2d_test.cc
rename to cartographer/mapping/2d/pose_graph_2d_test.cc
index 8366b98..4fc217f 100644
--- a/cartographer/mapping_2d/pose_graph_2d_test.cc
+++ b/cartographer/mapping/2d/pose_graph_2d_test.cc
@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-#include "cartographer/mapping_2d/pose_graph_2d.h"
+#include "cartographer/mapping/2d/pose_graph_2d.h"
 
 #include <cmath>
 #include <memory>
@@ -24,8 +24,8 @@
 #include "cartographer/common/make_unique.h"
 #include "cartographer/common/thread_pool.h"
 #include "cartographer/common/time.h"
-#include "cartographer/mapping_2d/range_data_inserter_2d.h"
-#include "cartographer/mapping_2d/submap_2d.h"
+#include "cartographer/mapping/2d/range_data_inserter_2d.h"
+#include "cartographer/mapping/2d/submap_2d.h"
 #include "cartographer/transform/rigid_transform.h"
 #include "cartographer/transform/rigid_transform_test_helpers.h"
 #include "cartographer/transform/transform.h"
diff --git a/cartographer/mapping_2d/probability_grid.cc b/cartographer/mapping/2d/probability_grid.cc
similarity index 99%
rename from cartographer/mapping_2d/probability_grid.cc
rename to cartographer/mapping/2d/probability_grid.cc
index 472bc43..dec5a89 100644
--- a/cartographer/mapping_2d/probability_grid.cc
+++ b/cartographer/mapping/2d/probability_grid.cc
@@ -1,4 +1,4 @@
-#include "cartographer/mapping_2d/probability_grid.h"
+#include "cartographer/mapping/2d/probability_grid.h"
 
 #include <limits>
 
diff --git a/cartographer/mapping_2d/probability_grid.h b/cartographer/mapping/2d/probability_grid.h
similarity index 95%
rename from cartographer/mapping_2d/probability_grid.h
rename to cartographer/mapping/2d/probability_grid.h
index 38ffe4a..7723f2e 100644
--- a/cartographer/mapping_2d/probability_grid.h
+++ b/cartographer/mapping/2d/probability_grid.h
@@ -20,9 +20,9 @@
 #include <vector>
 
 #include "cartographer/common/port.h"
-#include "cartographer/mapping_2d/map_limits.h"
-#include "cartographer/mapping_2d/proto/probability_grid.pb.h"
-#include "cartographer/mapping_2d/xy_index.h"
+#include "cartographer/mapping/2d/map_limits.h"
+#include "cartographer/mapping/2d/proto/probability_grid.pb.h"
+#include "cartographer/mapping/2d/xy_index.h"
 
 namespace cartographer {
 namespace mapping {
diff --git a/cartographer/mapping_2d/probability_grid_test.cc b/cartographer/mapping/2d/probability_grid_test.cc
similarity index 99%
rename from cartographer/mapping_2d/probability_grid_test.cc
rename to cartographer/mapping/2d/probability_grid_test.cc
index b9530ea..1cedc46 100644
--- a/cartographer/mapping_2d/probability_grid_test.cc
+++ b/cartographer/mapping/2d/probability_grid_test.cc
@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-#include "cartographer/mapping_2d/probability_grid.h"
+#include "cartographer/mapping/2d/probability_grid.h"
 
 #include <random>
 
diff --git a/cartographer/mapping_2d/proto/cell_limits.proto b/cartographer/mapping/2d/proto/cell_limits.proto
similarity index 100%
rename from cartographer/mapping_2d/proto/cell_limits.proto
rename to cartographer/mapping/2d/proto/cell_limits.proto
diff --git a/cartographer/mapping_2d/proto/local_trajectory_builder_options_2d.proto b/cartographer/mapping/2d/proto/local_trajectory_builder_options_2d.proto
similarity index 95%
rename from cartographer/mapping_2d/proto/local_trajectory_builder_options_2d.proto
rename to cartographer/mapping/2d/proto/local_trajectory_builder_options_2d.proto
index 5829384..1c9a91c 100644
--- a/cartographer/mapping_2d/proto/local_trajectory_builder_options_2d.proto
+++ b/cartographer/mapping/2d/proto/local_trajectory_builder_options_2d.proto
@@ -18,8 +18,8 @@ package cartographer.mapping.proto;
 
 import "cartographer/mapping/proto/motion_filter_options.proto";
 import "cartographer/sensor/proto/adaptive_voxel_filter_options.proto";
-import "cartographer/mapping_2d/proto/submaps_options_2d.proto";
-import "cartographer/mapping_2d/scan_matching/proto/ceres_scan_matcher_options_2d.proto";
+import "cartographer/mapping/2d/proto/submaps_options_2d.proto";
+import "cartographer/mapping/2d/scan_matching/proto/ceres_scan_matcher_options_2d.proto";
 import "cartographer/mapping/scan_matching/proto/real_time_correlative_scan_matcher_options.proto";
 
 message LocalTrajectoryBuilderOptions2D {
diff --git a/cartographer/mapping_2d/proto/map_limits.proto b/cartographer/mapping/2d/proto/map_limits.proto
similarity index 93%
rename from cartographer/mapping_2d/proto/map_limits.proto
rename to cartographer/mapping/2d/proto/map_limits.proto
index 592f3b7..20bd883 100644
--- a/cartographer/mapping_2d/proto/map_limits.proto
+++ b/cartographer/mapping/2d/proto/map_limits.proto
@@ -14,7 +14,7 @@
 
 syntax = "proto3";
 
-import "cartographer/mapping_2d/proto/cell_limits.proto";
+import "cartographer/mapping/2d/proto/cell_limits.proto";
 import "cartographer/transform/proto/transform.proto";
 
 package cartographer.mapping.proto;
diff --git a/cartographer/mapping_2d/proto/probability_grid.proto b/cartographer/mapping/2d/proto/probability_grid.proto
similarity index 94%
rename from cartographer/mapping_2d/proto/probability_grid.proto
rename to cartographer/mapping/2d/proto/probability_grid.proto
index 700e31c..7620249 100644
--- a/cartographer/mapping_2d/proto/probability_grid.proto
+++ b/cartographer/mapping/2d/proto/probability_grid.proto
@@ -14,7 +14,7 @@
 
 syntax = "proto3";
 
-import "cartographer/mapping_2d/proto/map_limits.proto";
+import "cartographer/mapping/2d/proto/map_limits.proto";
 
 package cartographer.mapping.proto;
 
diff --git a/cartographer/mapping_2d/proto/range_data_inserter_options_2d.proto b/cartographer/mapping/2d/proto/range_data_inserter_options_2d.proto
similarity index 100%
rename from cartographer/mapping_2d/proto/range_data_inserter_options_2d.proto
rename to cartographer/mapping/2d/proto/range_data_inserter_options_2d.proto
diff --git a/cartographer/mapping_2d/proto/submaps_options_2d.proto b/cartographer/mapping/2d/proto/submaps_options_2d.proto
similarity index 94%
rename from cartographer/mapping_2d/proto/submaps_options_2d.proto
rename to cartographer/mapping/2d/proto/submaps_options_2d.proto
index d8fa1f4..96f11bd 100644
--- a/cartographer/mapping_2d/proto/submaps_options_2d.proto
+++ b/cartographer/mapping/2d/proto/submaps_options_2d.proto
@@ -14,7 +14,7 @@
 
 syntax = "proto3";
 
-import "cartographer/mapping_2d/proto/range_data_inserter_options_2d.proto";
+import "cartographer/mapping/2d/proto/range_data_inserter_options_2d.proto";
 
 package cartographer.mapping.proto;
 
diff --git a/cartographer/mapping_2d/range_data_inserter_2d.cc b/cartographer/mapping/2d/range_data_inserter_2d.cc
similarity index 93%
rename from cartographer/mapping_2d/range_data_inserter_2d.cc
rename to cartographer/mapping/2d/range_data_inserter_2d.cc
index 4bbe288..387d2e0 100644
--- a/cartographer/mapping_2d/range_data_inserter_2d.cc
+++ b/cartographer/mapping/2d/range_data_inserter_2d.cc
@@ -14,15 +14,15 @@
  * limitations under the License.
  */
 
-#include "cartographer/mapping_2d/range_data_inserter_2d.h"
+#include "cartographer/mapping/2d/range_data_inserter_2d.h"
 
 #include <cstdlib>
 
 #include "Eigen/Core"
 #include "Eigen/Geometry"
+#include "cartographer/mapping/2d/ray_casting.h"
+#include "cartographer/mapping/2d/xy_index.h"
 #include "cartographer/mapping/probability_values.h"
-#include "cartographer/mapping_2d/ray_casting.h"
-#include "cartographer/mapping_2d/xy_index.h"
 #include "glog/logging.h"
 
 namespace cartographer {
diff --git a/cartographer/mapping_2d/range_data_inserter_2d.h b/cartographer/mapping/2d/range_data_inserter_2d.h
similarity index 91%
rename from cartographer/mapping_2d/range_data_inserter_2d.h
rename to cartographer/mapping/2d/range_data_inserter_2d.h
index 5211a67..ff6e0eb 100644
--- a/cartographer/mapping_2d/range_data_inserter_2d.h
+++ b/cartographer/mapping/2d/range_data_inserter_2d.h
@@ -22,9 +22,9 @@
 
 #include "cartographer/common/lua_parameter_dictionary.h"
 #include "cartographer/common/port.h"
-#include "cartographer/mapping_2d/probability_grid.h"
-#include "cartographer/mapping_2d/proto/range_data_inserter_options_2d.pb.h"
-#include "cartographer/mapping_2d/xy_index.h"
+#include "cartographer/mapping/2d/probability_grid.h"
+#include "cartographer/mapping/2d/proto/range_data_inserter_options_2d.pb.h"
+#include "cartographer/mapping/2d/xy_index.h"
 #include "cartographer/sensor/point_cloud.h"
 #include "cartographer/sensor/range_data.h"
 
diff --git a/cartographer/mapping_2d/range_data_inserter_2d_test.cc b/cartographer/mapping/2d/range_data_inserter_2d_test.cc
similarity index 97%
rename from cartographer/mapping_2d/range_data_inserter_2d_test.cc
rename to cartographer/mapping/2d/range_data_inserter_2d_test.cc
index d53f6d4..5a1b934 100644
--- a/cartographer/mapping_2d/range_data_inserter_2d_test.cc
+++ b/cartographer/mapping/2d/range_data_inserter_2d_test.cc
@@ -14,15 +14,15 @@
  * limitations under the License.
  */
 
-#include "cartographer/mapping_2d/range_data_inserter_2d.h"
+#include "cartographer/mapping/2d/range_data_inserter_2d.h"
 
 #include <memory>
 
 #include "cartographer/common/lua_parameter_dictionary.h"
 #include "cartographer/common/lua_parameter_dictionary_test_helpers.h"
 #include "cartographer/common/make_unique.h"
+#include "cartographer/mapping/2d/probability_grid.h"
 #include "cartographer/mapping/probability_values.h"
-#include "cartographer/mapping_2d/probability_grid.h"
 #include "gmock/gmock.h"
 
 namespace cartographer {
diff --git a/cartographer/mapping_2d/ray_casting.cc b/cartographer/mapping/2d/ray_casting.cc
similarity index 99%
rename from cartographer/mapping_2d/ray_casting.cc
rename to cartographer/mapping/2d/ray_casting.cc
index 9d9b3f8..6691e5d 100644
--- a/cartographer/mapping_2d/ray_casting.cc
+++ b/cartographer/mapping/2d/ray_casting.cc
@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-#include "cartographer/mapping_2d/ray_casting.h"
+#include "cartographer/mapping/2d/ray_casting.h"
 
 namespace cartographer {
 namespace mapping {
diff --git a/cartographer/mapping_2d/ray_casting.h b/cartographer/mapping/2d/ray_casting.h
similarity index 96%
rename from cartographer/mapping_2d/ray_casting.h
rename to cartographer/mapping/2d/ray_casting.h
index f9fe956..dee0c57 100644
--- a/cartographer/mapping_2d/ray_casting.h
+++ b/cartographer/mapping/2d/ray_casting.h
@@ -20,7 +20,7 @@
 #include <vector>
 
 #include "cartographer/common/port.h"
-#include "cartographer/mapping_2d/probability_grid.h"
+#include "cartographer/mapping/2d/probability_grid.h"
 #include "cartographer/sensor/point_cloud.h"
 #include "cartographer/sensor/range_data.h"
 #include "cartographer/transform/transform.h"
diff --git a/cartographer/mapping_2d/scan_matching/ceres_scan_matcher_2d.cc b/cartographer/mapping/2d/scan_matching/ceres_scan_matcher_2d.cc
similarity index 92%
rename from cartographer/mapping_2d/scan_matching/ceres_scan_matcher_2d.cc
rename to cartographer/mapping/2d/scan_matching/ceres_scan_matcher_2d.cc
index e98eb6d..69776d1 100644
--- a/cartographer/mapping_2d/scan_matching/ceres_scan_matcher_2d.cc
+++ b/cartographer/mapping/2d/scan_matching/ceres_scan_matcher_2d.cc
@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-#include "cartographer/mapping_2d/scan_matching/ceres_scan_matcher_2d.h"
+#include "cartographer/mapping/2d/scan_matching/ceres_scan_matcher_2d.h"
 
 #include <utility>
 #include <vector>
@@ -22,10 +22,10 @@
 #include "Eigen/Core"
 #include "cartographer/common/ceres_solver_options.h"
 #include "cartographer/common/lua_parameter_dictionary.h"
-#include "cartographer/internal/mapping_2d/scan_matching/occupied_space_cost_function_2d.h"
-#include "cartographer/mapping_2d/probability_grid.h"
-#include "cartographer/mapping_2d/scan_matching/rotation_delta_cost_functor_2d.h"
-#include "cartographer/mapping_2d/scan_matching/translation_delta_cost_functor_2d.h"
+#include "cartographer/internal/mapping/2d/scan_matching/occupied_space_cost_function_2d.h"
+#include "cartographer/mapping/2d/probability_grid.h"
+#include "cartographer/mapping/2d/scan_matching/rotation_delta_cost_functor_2d.h"
+#include "cartographer/mapping/2d/scan_matching/translation_delta_cost_functor_2d.h"
 #include "cartographer/transform/transform.h"
 #include "ceres/ceres.h"
 #include "glog/logging.h"
diff --git a/cartographer/mapping_2d/scan_matching/ceres_scan_matcher_2d.h b/cartographer/mapping/2d/scan_matching/ceres_scan_matcher_2d.h
similarity index 95%
rename from cartographer/mapping_2d/scan_matching/ceres_scan_matcher_2d.h
rename to cartographer/mapping/2d/scan_matching/ceres_scan_matcher_2d.h
index 5b124e1..d517754 100644
--- a/cartographer/mapping_2d/scan_matching/ceres_scan_matcher_2d.h
+++ b/cartographer/mapping/2d/scan_matching/ceres_scan_matcher_2d.h
@@ -22,8 +22,8 @@
 
 #include "Eigen/Core"
 #include "cartographer/common/lua_parameter_dictionary.h"
-#include "cartographer/mapping_2d/probability_grid.h"
-#include "cartographer/mapping_2d/scan_matching/proto/ceres_scan_matcher_options_2d.pb.h"
+#include "cartographer/mapping/2d/probability_grid.h"
+#include "cartographer/mapping/2d/scan_matching/proto/ceres_scan_matcher_options_2d.pb.h"
 #include "cartographer/sensor/point_cloud.h"
 #include "ceres/ceres.h"
 
diff --git a/cartographer/mapping_2d/scan_matching/ceres_scan_matcher_2d_test.cc b/cartographer/mapping/2d/scan_matching/ceres_scan_matcher_2d_test.cc
similarity index 96%
rename from cartographer/mapping_2d/scan_matching/ceres_scan_matcher_2d_test.cc
rename to cartographer/mapping/2d/scan_matching/ceres_scan_matcher_2d_test.cc
index d5b49c6..6cf4788 100644
--- a/cartographer/mapping_2d/scan_matching/ceres_scan_matcher_2d_test.cc
+++ b/cartographer/mapping/2d/scan_matching/ceres_scan_matcher_2d_test.cc
@@ -14,15 +14,15 @@
  * limitations under the License.
  */
 
-#include "cartographer/mapping_2d/scan_matching/ceres_scan_matcher_2d.h"
+#include "cartographer/mapping/2d/scan_matching/ceres_scan_matcher_2d.h"
 
 #include <memory>
 
 #include "cartographer/common/lua_parameter_dictionary.h"
 #include "cartographer/common/lua_parameter_dictionary_test_helpers.h"
 #include "cartographer/common/make_unique.h"
+#include "cartographer/mapping/2d/probability_grid.h"
 #include "cartographer/mapping/probability_values.h"
-#include "cartographer/mapping_2d/probability_grid.h"
 #include "cartographer/sensor/point_cloud.h"
 #include "cartographer/transform/rigid_transform_test_helpers.h"
 #include "gtest/gtest.h"
diff --git a/cartographer/mapping_2d/scan_matching/correlative_scan_matcher_2d.cc b/cartographer/mapping/2d/scan_matching/correlative_scan_matcher_2d.cc
similarity index 98%
rename from cartographer/mapping_2d/scan_matching/correlative_scan_matcher_2d.cc
rename to cartographer/mapping/2d/scan_matching/correlative_scan_matcher_2d.cc
index d7b5de6..12b8529 100644
--- a/cartographer/mapping_2d/scan_matching/correlative_scan_matcher_2d.cc
+++ b/cartographer/mapping/2d/scan_matching/correlative_scan_matcher_2d.cc
@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-#include "cartographer/mapping_2d/scan_matching/correlative_scan_matcher_2d.h"
+#include "cartographer/mapping/2d/scan_matching/correlative_scan_matcher_2d.h"
 
 #include <cmath>
 
diff --git a/cartographer/mapping_2d/scan_matching/correlative_scan_matcher_2d.h b/cartographer/mapping/2d/scan_matching/correlative_scan_matcher_2d.h
similarity index 97%
rename from cartographer/mapping_2d/scan_matching/correlative_scan_matcher_2d.h
rename to cartographer/mapping/2d/scan_matching/correlative_scan_matcher_2d.h
index 515402e..205d5d9 100644
--- a/cartographer/mapping_2d/scan_matching/correlative_scan_matcher_2d.h
+++ b/cartographer/mapping/2d/scan_matching/correlative_scan_matcher_2d.h
@@ -21,8 +21,8 @@
 
 #include "Eigen/Core"
 #include "cartographer/common/lua_parameter_dictionary.h"
-#include "cartographer/mapping_2d/map_limits.h"
-#include "cartographer/mapping_2d/xy_index.h"
+#include "cartographer/mapping/2d/map_limits.h"
+#include "cartographer/mapping/2d/xy_index.h"
 #include "cartographer/sensor/point_cloud.h"
 
 namespace cartographer {
diff --git a/cartographer/mapping_2d/scan_matching/correlative_scan_matcher_test.cc b/cartographer/mapping/2d/scan_matching/correlative_scan_matcher_test.cc
similarity index 98%
rename from cartographer/mapping_2d/scan_matching/correlative_scan_matcher_test.cc
rename to cartographer/mapping/2d/scan_matching/correlative_scan_matcher_test.cc
index 1fa9072..6e16e90 100644
--- a/cartographer/mapping_2d/scan_matching/correlative_scan_matcher_test.cc
+++ b/cartographer/mapping/2d/scan_matching/correlative_scan_matcher_test.cc
@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-#include "cartographer/mapping_2d/scan_matching/correlative_scan_matcher_2d.h"
+#include "cartographer/mapping/2d/scan_matching/correlative_scan_matcher_2d.h"
 
 #include "cartographer/sensor/point_cloud.h"
 #include "gtest/gtest.h"
diff --git a/cartographer/mapping_2d/scan_matching/fast_correlative_scan_matcher_2d.cc b/cartographer/mapping/2d/scan_matching/fast_correlative_scan_matcher_2d.cc
similarity index 99%
rename from cartographer/mapping_2d/scan_matching/fast_correlative_scan_matcher_2d.cc
rename to cartographer/mapping/2d/scan_matching/fast_correlative_scan_matcher_2d.cc
index 3cba7af..7530f76 100644
--- a/cartographer/mapping_2d/scan_matching/fast_correlative_scan_matcher_2d.cc
+++ b/cartographer/mapping/2d/scan_matching/fast_correlative_scan_matcher_2d.cc
@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-#include "cartographer/mapping_2d/scan_matching/fast_correlative_scan_matcher_2d.h"
+#include "cartographer/mapping/2d/scan_matching/fast_correlative_scan_matcher_2d.h"
 
 #include <algorithm>
 #include <cmath>
@@ -24,7 +24,7 @@
 
 #include "Eigen/Geometry"
 #include "cartographer/common/math.h"
-#include "cartographer/mapping_2d/probability_grid.h"
+#include "cartographer/mapping/2d/probability_grid.h"
 #include "cartographer/sensor/point_cloud.h"
 #include "cartographer/transform/transform.h"
 #include "glog/logging.h"
diff --git a/cartographer/mapping_2d/scan_matching/fast_correlative_scan_matcher_2d.h b/cartographer/mapping/2d/scan_matching/fast_correlative_scan_matcher_2d.h
similarity index 97%
rename from cartographer/mapping_2d/scan_matching/fast_correlative_scan_matcher_2d.h
rename to cartographer/mapping/2d/scan_matching/fast_correlative_scan_matcher_2d.h
index 819f373..3f62e44 100644
--- a/cartographer/mapping_2d/scan_matching/fast_correlative_scan_matcher_2d.h
+++ b/cartographer/mapping/2d/scan_matching/fast_correlative_scan_matcher_2d.h
@@ -30,10 +30,10 @@
 
 #include "Eigen/Core"
 #include "cartographer/common/port.h"
+#include "cartographer/mapping/2d/probability_grid.h"
+#include "cartographer/mapping/2d/scan_matching/correlative_scan_matcher_2d.h"
+#include "cartographer/mapping/2d/scan_matching/proto/fast_correlative_scan_matcher_options_2d.pb.h"
 #include "cartographer/mapping/probability_values.h"
-#include "cartographer/mapping_2d/probability_grid.h"
-#include "cartographer/mapping_2d/scan_matching/correlative_scan_matcher_2d.h"
-#include "cartographer/mapping_2d/scan_matching/proto/fast_correlative_scan_matcher_options_2d.pb.h"
 #include "cartographer/sensor/point_cloud.h"
 
 namespace cartographer {
diff --git a/cartographer/mapping_2d/scan_matching/fast_correlative_scan_matcher_2d_test.cc b/cartographer/mapping/2d/scan_matching/fast_correlative_scan_matcher_2d_test.cc
similarity index 98%
rename from cartographer/mapping_2d/scan_matching/fast_correlative_scan_matcher_2d_test.cc
rename to cartographer/mapping/2d/scan_matching/fast_correlative_scan_matcher_2d_test.cc
index 118fef2..d540d9e 100644
--- a/cartographer/mapping_2d/scan_matching/fast_correlative_scan_matcher_2d_test.cc
+++ b/cartographer/mapping/2d/scan_matching/fast_correlative_scan_matcher_2d_test.cc
@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-#include "cartographer/mapping_2d/scan_matching/fast_correlative_scan_matcher_2d.h"
+#include "cartographer/mapping/2d/scan_matching/fast_correlative_scan_matcher_2d.h"
 
 #include <algorithm>
 #include <cmath>
@@ -23,8 +23,8 @@
 #include <string>
 
 #include "cartographer/common/lua_parameter_dictionary_test_helpers.h"
-#include "cartographer/mapping_2d/probability_grid.h"
-#include "cartographer/mapping_2d/range_data_inserter_2d.h"
+#include "cartographer/mapping/2d/probability_grid.h"
+#include "cartographer/mapping/2d/range_data_inserter_2d.h"
 #include "cartographer/transform/rigid_transform_test_helpers.h"
 #include "cartographer/transform/transform.h"
 #include "gtest/gtest.h"
diff --git a/cartographer/mapping_2d/scan_matching/fast_global_localizer.cc b/cartographer/mapping/2d/scan_matching/fast_global_localizer.cc
similarity index 96%
rename from cartographer/mapping_2d/scan_matching/fast_global_localizer.cc
rename to cartographer/mapping/2d/scan_matching/fast_global_localizer.cc
index 02c4f5f..fab9d77 100644
--- a/cartographer/mapping_2d/scan_matching/fast_global_localizer.cc
+++ b/cartographer/mapping/2d/scan_matching/fast_global_localizer.cc
@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-#include "cartographer/mapping_2d/scan_matching/fast_global_localizer.h"
+#include "cartographer/mapping/2d/scan_matching/fast_global_localizer.h"
 
 #include "glog/logging.h"
 
diff --git a/cartographer/mapping_2d/scan_matching/fast_global_localizer.h b/cartographer/mapping/2d/scan_matching/fast_global_localizer.h
similarity index 96%
rename from cartographer/mapping_2d/scan_matching/fast_global_localizer.h
rename to cartographer/mapping/2d/scan_matching/fast_global_localizer.h
index e15f204..ad8acfb 100644
--- a/cartographer/mapping_2d/scan_matching/fast_global_localizer.h
+++ b/cartographer/mapping/2d/scan_matching/fast_global_localizer.h
@@ -20,7 +20,7 @@
 #include <vector>
 
 #include "Eigen/Geometry"
-#include "cartographer/mapping_2d/scan_matching/fast_correlative_scan_matcher_2d.h"
+#include "cartographer/mapping/2d/scan_matching/fast_correlative_scan_matcher_2d.h"
 #include "cartographer/sensor/voxel_filter.h"
 
 namespace cartographer {
diff --git a/cartographer/mapping_2d/scan_matching/proto/ceres_scan_matcher_options_2d.proto b/cartographer/mapping/2d/scan_matching/proto/ceres_scan_matcher_options_2d.proto
similarity index 100%
rename from cartographer/mapping_2d/scan_matching/proto/ceres_scan_matcher_options_2d.proto
rename to cartographer/mapping/2d/scan_matching/proto/ceres_scan_matcher_options_2d.proto
diff --git a/cartographer/mapping_2d/scan_matching/proto/fast_correlative_scan_matcher_options_2d.proto b/cartographer/mapping/2d/scan_matching/proto/fast_correlative_scan_matcher_options_2d.proto
similarity index 100%
rename from cartographer/mapping_2d/scan_matching/proto/fast_correlative_scan_matcher_options_2d.proto
rename to cartographer/mapping/2d/scan_matching/proto/fast_correlative_scan_matcher_options_2d.proto
diff --git a/cartographer/mapping_2d/scan_matching/real_time_correlative_scan_matcher_2d.cc b/cartographer/mapping/2d/scan_matching/real_time_correlative_scan_matcher_2d.cc
similarity index 97%
rename from cartographer/mapping_2d/scan_matching/real_time_correlative_scan_matcher_2d.cc
rename to cartographer/mapping/2d/scan_matching/real_time_correlative_scan_matcher_2d.cc
index aeeb607..f1d45e7 100644
--- a/cartographer/mapping_2d/scan_matching/real_time_correlative_scan_matcher_2d.cc
+++ b/cartographer/mapping/2d/scan_matching/real_time_correlative_scan_matcher_2d.cc
@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-#include "cartographer/mapping_2d/scan_matching/real_time_correlative_scan_matcher_2d.h"
+#include "cartographer/mapping/2d/scan_matching/real_time_correlative_scan_matcher_2d.h"
 
 #include <algorithm>
 #include <cmath>
@@ -24,7 +24,7 @@
 #include "Eigen/Geometry"
 #include "cartographer/common/lua_parameter_dictionary.h"
 #include "cartographer/common/math.h"
-#include "cartographer/mapping_2d/probability_grid.h"
+#include "cartographer/mapping/2d/probability_grid.h"
 #include "cartographer/sensor/point_cloud.h"
 #include "cartographer/transform/transform.h"
 #include "glog/logging.h"
diff --git a/cartographer/mapping_2d/scan_matching/real_time_correlative_scan_matcher_2d.h b/cartographer/mapping/2d/scan_matching/real_time_correlative_scan_matcher_2d.h
similarity index 96%
rename from cartographer/mapping_2d/scan_matching/real_time_correlative_scan_matcher_2d.h
rename to cartographer/mapping/2d/scan_matching/real_time_correlative_scan_matcher_2d.h
index fcad1c1..3b7e919 100644
--- a/cartographer/mapping_2d/scan_matching/real_time_correlative_scan_matcher_2d.h
+++ b/cartographer/mapping/2d/scan_matching/real_time_correlative_scan_matcher_2d.h
@@ -41,10 +41,10 @@
 #include <vector>
 
 #include "Eigen/Core"
+#include "cartographer/mapping/2d/probability_grid.h"
+#include "cartographer/mapping/2d/scan_matching/correlative_scan_matcher_2d.h"
 #include "cartographer/mapping/scan_matching/proto/real_time_correlative_scan_matcher_options.pb.h"
 #include "cartographer/mapping/scan_matching/real_time_correlative_scan_matcher.h"
-#include "cartographer/mapping_2d/probability_grid.h"
-#include "cartographer/mapping_2d/scan_matching/correlative_scan_matcher_2d.h"
 
 namespace cartographer {
 namespace mapping {
diff --git a/cartographer/mapping_2d/scan_matching/real_time_correlative_scan_matcher_2d_test.cc b/cartographer/mapping/2d/scan_matching/real_time_correlative_scan_matcher_2d_test.cc
similarity index 96%
rename from cartographer/mapping_2d/scan_matching/real_time_correlative_scan_matcher_2d_test.cc
rename to cartographer/mapping/2d/scan_matching/real_time_correlative_scan_matcher_2d_test.cc
index 0b25c10..d66c6fc 100644
--- a/cartographer/mapping_2d/scan_matching/real_time_correlative_scan_matcher_2d_test.cc
+++ b/cartographer/mapping/2d/scan_matching/real_time_correlative_scan_matcher_2d_test.cc
@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-#include "cartographer/mapping_2d/scan_matching/real_time_correlative_scan_matcher_2d.h"
+#include "cartographer/mapping/2d/scan_matching/real_time_correlative_scan_matcher_2d.h"
 
 #include <cmath>
 #include <memory>
@@ -22,8 +22,8 @@
 #include "Eigen/Geometry"
 #include "cartographer/common/lua_parameter_dictionary_test_helpers.h"
 #include "cartographer/common/make_unique.h"
-#include "cartographer/mapping_2d/probability_grid.h"
-#include "cartographer/mapping_2d/range_data_inserter_2d.h"
+#include "cartographer/mapping/2d/probability_grid.h"
+#include "cartographer/mapping/2d/range_data_inserter_2d.h"
 #include "cartographer/sensor/point_cloud.h"
 #include "cartographer/transform/transform.h"
 #include "gtest/gtest.h"
diff --git a/cartographer/mapping_2d/scan_matching/rotation_delta_cost_functor_2d.h b/cartographer/mapping/2d/scan_matching/rotation_delta_cost_functor_2d.h
similarity index 100%
rename from cartographer/mapping_2d/scan_matching/rotation_delta_cost_functor_2d.h
rename to cartographer/mapping/2d/scan_matching/rotation_delta_cost_functor_2d.h
diff --git a/cartographer/mapping_2d/scan_matching/translation_delta_cost_functor_2d.h b/cartographer/mapping/2d/scan_matching/translation_delta_cost_functor_2d.h
similarity index 100%
rename from cartographer/mapping_2d/scan_matching/translation_delta_cost_functor_2d.h
rename to cartographer/mapping/2d/scan_matching/translation_delta_cost_functor_2d.h
diff --git a/cartographer/mapping_2d/submap_2d.cc b/cartographer/mapping/2d/submap_2d.cc
similarity index 99%
rename from cartographer/mapping_2d/submap_2d.cc
rename to cartographer/mapping/2d/submap_2d.cc
index 1d2d1d6..2016af7 100644
--- a/cartographer/mapping_2d/submap_2d.cc
+++ b/cartographer/mapping/2d/submap_2d.cc
@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-#include "cartographer/mapping_2d/submap_2d.h"
+#include "cartographer/mapping/2d/submap_2d.h"
 
 #include <cinttypes>
 #include <cmath>
diff --git a/cartographer/mapping_2d/submap_2d.h b/cartographer/mapping/2d/submap_2d.h
similarity index 94%
rename from cartographer/mapping_2d/submap_2d.h
rename to cartographer/mapping/2d/submap_2d.h
index 2793aaa..ba35e4c 100644
--- a/cartographer/mapping_2d/submap_2d.h
+++ b/cartographer/mapping/2d/submap_2d.h
@@ -22,14 +22,14 @@
 
 #include "Eigen/Core"
 #include "cartographer/common/lua_parameter_dictionary.h"
+#include "cartographer/mapping/2d/map_limits.h"
+#include "cartographer/mapping/2d/probability_grid.h"
+#include "cartographer/mapping/2d/proto/submaps_options_2d.pb.h"
+#include "cartographer/mapping/2d/range_data_inserter_2d.h"
 #include "cartographer/mapping/proto/serialization.pb.h"
 #include "cartographer/mapping/proto/submap_visualization.pb.h"
 #include "cartographer/mapping/submaps.h"
 #include "cartographer/mapping/trajectory_node.h"
-#include "cartographer/mapping_2d/map_limits.h"
-#include "cartographer/mapping_2d/probability_grid.h"
-#include "cartographer/mapping_2d/proto/submaps_options_2d.pb.h"
-#include "cartographer/mapping_2d/range_data_inserter_2d.h"
 #include "cartographer/sensor/range_data.h"
 #include "cartographer/transform/rigid_transform.h"
 
diff --git a/cartographer/mapping_2d/submap_2d_test.cc b/cartographer/mapping/2d/submap_2d_test.cc
similarity index 98%
rename from cartographer/mapping_2d/submap_2d_test.cc
rename to cartographer/mapping/2d/submap_2d_test.cc
index 075e1d0..64380c1 100644
--- a/cartographer/mapping_2d/submap_2d_test.cc
+++ b/cartographer/mapping/2d/submap_2d_test.cc
@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-#include "cartographer/mapping_2d/submap_2d.h"
+#include "cartographer/mapping/2d/submap_2d.h"
 
 #include <map>
 #include <memory>
diff --git a/cartographer/mapping_2d/xy_index.h b/cartographer/mapping/2d/xy_index.h
similarity index 98%
rename from cartographer/mapping_2d/xy_index.h
rename to cartographer/mapping/2d/xy_index.h
index 1e11629..1d0e78b 100644
--- a/cartographer/mapping_2d/xy_index.h
+++ b/cartographer/mapping/2d/xy_index.h
@@ -25,7 +25,7 @@
 #include "Eigen/Core"
 #include "cartographer/common/math.h"
 #include "cartographer/common/port.h"
-#include "cartographer/mapping_2d/proto/cell_limits.pb.h"
+#include "cartographer/mapping/2d/proto/cell_limits.pb.h"
 #include "glog/logging.h"
 
 namespace cartographer {
diff --git a/cartographer/mapping_2d/xy_index_test.cc b/cartographer/mapping/2d/xy_index_test.cc
similarity index 97%
rename from cartographer/mapping_2d/xy_index_test.cc
rename to cartographer/mapping/2d/xy_index_test.cc
index ad750e0..e80dfc4 100644
--- a/cartographer/mapping_2d/xy_index_test.cc
+++ b/cartographer/mapping/2d/xy_index_test.cc
@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-#include "cartographer/mapping_2d/xy_index.h"
+#include "cartographer/mapping/2d/xy_index.h"
 
 #include "gtest/gtest.h"
 
diff --git a/cartographer/mapping_3d/hybrid_grid.h b/cartographer/mapping/3d/hybrid_grid.h
similarity index 99%
rename from cartographer/mapping_3d/hybrid_grid.h
rename to cartographer/mapping/3d/hybrid_grid.h
index b5fa75e..c9e19c6 100644
--- a/cartographer/mapping_3d/hybrid_grid.h
+++ b/cartographer/mapping/3d/hybrid_grid.h
@@ -27,8 +27,8 @@
 #include "cartographer/common/make_unique.h"
 #include "cartographer/common/math.h"
 #include "cartographer/common/port.h"
+#include "cartographer/mapping/3d/proto/hybrid_grid.pb.h"
 #include "cartographer/mapping/probability_values.h"
-#include "cartographer/mapping_3d/proto/hybrid_grid.pb.h"
 #include "cartographer/transform/transform.h"
 #include "glog/logging.h"
 
diff --git a/cartographer/mapping_3d/hybrid_grid_test.cc b/cartographer/mapping/3d/hybrid_grid_test.cc
similarity index 99%
rename from cartographer/mapping_3d/hybrid_grid_test.cc
rename to cartographer/mapping/3d/hybrid_grid_test.cc
index aba7c75..62309de 100644
--- a/cartographer/mapping_3d/hybrid_grid_test.cc
+++ b/cartographer/mapping/3d/hybrid_grid_test.cc
@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-#include "cartographer/mapping_3d/hybrid_grid.h"
+#include "cartographer/mapping/3d/hybrid_grid.h"
 
 #include <map>
 #include <random>
diff --git a/cartographer/mapping_3d/imu_integration.h b/cartographer/mapping/3d/imu_integration.h
similarity index 100%
rename from cartographer/mapping_3d/imu_integration.h
rename to cartographer/mapping/3d/imu_integration.h
diff --git a/cartographer/mapping_3d/local_trajectory_builder_options_3d.cc b/cartographer/mapping/3d/local_trajectory_builder_options_3d.cc
similarity index 94%
rename from cartographer/mapping_3d/local_trajectory_builder_options_3d.cc
rename to cartographer/mapping/3d/local_trajectory_builder_options_3d.cc
index 134fc72..efc464d 100644
--- a/cartographer/mapping_3d/local_trajectory_builder_options_3d.cc
+++ b/cartographer/mapping/3d/local_trajectory_builder_options_3d.cc
@@ -14,12 +14,12 @@
  * limitations under the License.
  */
 
-#include "cartographer/mapping_3d/local_trajectory_builder_options_3d.h"
+#include "cartographer/mapping/3d/local_trajectory_builder_options_3d.h"
 
 #include "cartographer/internal/mapping/motion_filter.h"
+#include "cartographer/mapping/3d/scan_matching/ceres_scan_matcher_3d.h"
+#include "cartographer/mapping/3d/submap_3d.h"
 #include "cartographer/mapping/scan_matching/real_time_correlative_scan_matcher.h"
-#include "cartographer/mapping_3d/scan_matching/ceres_scan_matcher_3d.h"
-#include "cartographer/mapping_3d/submap_3d.h"
 #include "cartographer/sensor/voxel_filter.h"
 #include "glog/logging.h"
 
diff --git a/cartographer/mapping_3d/local_trajectory_builder_options_3d.h b/cartographer/mapping/3d/local_trajectory_builder_options_3d.h
similarity index 94%
rename from cartographer/mapping_3d/local_trajectory_builder_options_3d.h
rename to cartographer/mapping/3d/local_trajectory_builder_options_3d.h
index 7c0dc5c..e7165c5 100644
--- a/cartographer/mapping_3d/local_trajectory_builder_options_3d.h
+++ b/cartographer/mapping/3d/local_trajectory_builder_options_3d.h
@@ -18,7 +18,7 @@
 #define CARTOGRAPHER_MAPPING_3D_LOCAL_TRAJECTORY_BUILDER_OPTIONS_3D_H_
 
 #include "cartographer/common/lua_parameter_dictionary.h"
-#include "cartographer/mapping_3d/proto/local_trajectory_builder_options_3d.pb.h"
+#include "cartographer/mapping/3d/proto/local_trajectory_builder_options_3d.pb.h"
 
 namespace cartographer {
 namespace mapping {
diff --git a/cartographer/mapping_3d/pose_graph/constraint_builder_3d.cc b/cartographer/mapping/3d/pose_graph/constraint_builder_3d.cc
similarity index 97%
rename from cartographer/mapping_3d/pose_graph/constraint_builder_3d.cc
rename to cartographer/mapping/3d/pose_graph/constraint_builder_3d.cc
index 03f5972..3fda925 100644
--- a/cartographer/mapping_3d/pose_graph/constraint_builder_3d.cc
+++ b/cartographer/mapping/3d/pose_graph/constraint_builder_3d.cc
@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-#include "cartographer/mapping_3d/pose_graph/constraint_builder_3d.h"
+#include "cartographer/mapping/3d/pose_graph/constraint_builder_3d.h"
 
 #include <cmath>
 #include <functional>
@@ -29,8 +29,8 @@
 #include "cartographer/common/make_unique.h"
 #include "cartographer/common/math.h"
 #include "cartographer/common/thread_pool.h"
-#include "cartographer/mapping_3d/scan_matching/proto/ceres_scan_matcher_options_3d.pb.h"
-#include "cartographer/mapping_3d/scan_matching/proto/fast_correlative_scan_matcher_options_3d.pb.h"
+#include "cartographer/mapping/3d/scan_matching/proto/ceres_scan_matcher_options_3d.pb.h"
+#include "cartographer/mapping/3d/scan_matching/proto/fast_correlative_scan_matcher_options_3d.pb.h"
 #include "cartographer/metrics/counter.h"
 #include "cartographer/metrics/gauge.h"
 #include "cartographer/metrics/histogram.h"
@@ -340,7 +340,7 @@ void ConstraintBuilder3D::DeleteScanMatcher(const SubmapId& submap_id) {
 
 void ConstraintBuilder3D::RegisterMetrics(metrics::FamilyFactory* factory) {
   auto* counts = factory->NewCounterFamily(
-      "/mapping_3d/pose_graph/constraint_builder/constraints",
+      "/mapping/3d/pose_graph/constraint_builder/constraints",
       "Constraints computed");
   kConstraintsSearchedMetric =
       counts->Add({{"search_region", "local"}, {"matcher", "searched"}});
@@ -351,11 +351,11 @@ void ConstraintBuilder3D::RegisterMetrics(metrics::FamilyFactory* factory) {
   kGlobalConstraintsFoundMetric =
       counts->Add({{"search_region", "global"}, {"matcher", "found"}});
   auto* queue_length = factory->NewGaugeFamily(
-      "/mapping_3d/pose_graph/constraint_builder/queue_length", "Queue length");
+      "/mapping/3d/pose_graph/constraint_builder/queue_length", "Queue length");
   kQueueLengthMetric = queue_length->Add({{}});
   auto boundaries = metrics::Histogram::FixedWidth(0.05, 20);
   auto* scores = factory->NewHistogramFamily(
-      "/mapping_3d/pose_graph/constraint_builder/scores",
+      "/mapping/3d/pose_graph/constraint_builder/scores",
       "Constraint scores built", boundaries);
   kConstraintScoresMetric =
       scores->Add({{"search_region", "local"}, {"kind", "score"}});
diff --git a/cartographer/mapping_3d/pose_graph/constraint_builder_3d.h b/cartographer/mapping/3d/pose_graph/constraint_builder_3d.h
similarity index 97%
rename from cartographer/mapping_3d/pose_graph/constraint_builder_3d.h
rename to cartographer/mapping/3d/pose_graph/constraint_builder_3d.h
index 9b66f2f..f90e575 100644
--- a/cartographer/mapping_3d/pose_graph/constraint_builder_3d.h
+++ b/cartographer/mapping/3d/pose_graph/constraint_builder_3d.h
@@ -31,12 +31,12 @@
 #include "cartographer/common/math.h"
 #include "cartographer/common/mutex.h"
 #include "cartographer/common/thread_pool.h"
+#include "cartographer/mapping/3d/scan_matching/ceres_scan_matcher_3d.h"
+#include "cartographer/mapping/3d/scan_matching/fast_correlative_scan_matcher_3d.h"
+#include "cartographer/mapping/3d/submap_3d.h"
 #include "cartographer/mapping/pose_graph/proto/constraint_builder_options.pb.h"
 #include "cartographer/mapping/pose_graph_interface.h"
 #include "cartographer/mapping/trajectory_node.h"
-#include "cartographer/mapping_3d/scan_matching/ceres_scan_matcher_3d.h"
-#include "cartographer/mapping_3d/scan_matching/fast_correlative_scan_matcher_3d.h"
-#include "cartographer/mapping_3d/submap_3d.h"
 #include "cartographer/metrics/family_factory.h"
 #include "cartographer/sensor/compressed_point_cloud.h"
 #include "cartographer/sensor/point_cloud.h"
diff --git a/cartographer/mapping_3d/pose_graph/landmark_cost_function_3d.h b/cartographer/mapping/3d/pose_graph/landmark_cost_function_3d.h
similarity index 98%
rename from cartographer/mapping_3d/pose_graph/landmark_cost_function_3d.h
rename to cartographer/mapping/3d/pose_graph/landmark_cost_function_3d.h
index ebaa415..520b75d 100644
--- a/cartographer/mapping_3d/pose_graph/landmark_cost_function_3d.h
+++ b/cartographer/mapping/3d/pose_graph/landmark_cost_function_3d.h
@@ -19,9 +19,9 @@
 
 #include "Eigen/Core"
 #include "Eigen/Geometry"
+#include "cartographer/mapping/3d/pose_graph/optimization_problem_3d.h"
 #include "cartographer/mapping/pose_graph/cost_helpers.h"
 #include "cartographer/mapping/pose_graph_interface.h"
-#include "cartographer/mapping_3d/pose_graph/optimization_problem_3d.h"
 #include "cartographer/transform/rigid_transform.h"
 #include "cartographer/transform/transform.h"
 #include "ceres/ceres.h"
diff --git a/cartographer/mapping_3d/pose_graph/landmark_cost_function_3d_test.cc b/cartographer/mapping/3d/pose_graph/landmark_cost_function_3d_test.cc
similarity index 97%
rename from cartographer/mapping_3d/pose_graph/landmark_cost_function_3d_test.cc
rename to cartographer/mapping/3d/pose_graph/landmark_cost_function_3d_test.cc
index 0e2aa49..543395b 100644
--- a/cartographer/mapping_3d/pose_graph/landmark_cost_function_3d_test.cc
+++ b/cartographer/mapping/3d/pose_graph/landmark_cost_function_3d_test.cc
@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-#include "cartographer/mapping_3d/pose_graph/landmark_cost_function_3d.h"
+#include "cartographer/mapping/3d/pose_graph/landmark_cost_function_3d.h"
 
 #include <memory>
 
diff --git a/cartographer/mapping_3d/pose_graph/optimization_problem_3d.cc b/cartographer/mapping/3d/pose_graph/optimization_problem_3d.cc
similarity index 98%
rename from cartographer/mapping_3d/pose_graph/optimization_problem_3d.cc
rename to cartographer/mapping/3d/pose_graph/optimization_problem_3d.cc
index 835d52b..5ce557f 100644
--- a/cartographer/mapping_3d/pose_graph/optimization_problem_3d.cc
+++ b/cartographer/mapping/3d/pose_graph/optimization_problem_3d.cc
@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-#include "cartographer/mapping_3d/pose_graph/optimization_problem_3d.h"
+#include "cartographer/mapping/3d/pose_graph/optimization_problem_3d.h"
 
 #include <algorithm>
 #include <array>
@@ -30,13 +30,13 @@
 #include "cartographer/common/make_unique.h"
 #include "cartographer/common/math.h"
 #include "cartographer/common/time.h"
-#include "cartographer/internal/mapping_3d/acceleration_cost_function_3d.h"
-#include "cartographer/internal/mapping_3d/rotation_cost_function_3d.h"
+#include "cartographer/internal/mapping/3d/acceleration_cost_function_3d.h"
+#include "cartographer/internal/mapping/3d/rotation_cost_function_3d.h"
+#include "cartographer/mapping/3d/imu_integration.h"
+#include "cartographer/mapping/3d/pose_graph/landmark_cost_function_3d.h"
+#include "cartographer/mapping/3d/pose_graph/spa_cost_function_3d.h"
+#include "cartographer/mapping/3d/rotation_parameterization.h"
 #include "cartographer/mapping/pose_graph/ceres_pose.h"
-#include "cartographer/mapping_3d/imu_integration.h"
-#include "cartographer/mapping_3d/pose_graph/landmark_cost_function_3d.h"
-#include "cartographer/mapping_3d/pose_graph/spa_cost_function_3d.h"
-#include "cartographer/mapping_3d/rotation_parameterization.h"
 #include "cartographer/transform/timestamped_transform.h"
 #include "cartographer/transform/transform.h"
 #include "ceres/ceres.h"
diff --git a/cartographer/mapping_3d/pose_graph/optimization_problem_3d.h b/cartographer/mapping/3d/pose_graph/optimization_problem_3d.h
similarity index 100%
rename from cartographer/mapping_3d/pose_graph/optimization_problem_3d.h
rename to cartographer/mapping/3d/pose_graph/optimization_problem_3d.h
diff --git a/cartographer/mapping_3d/pose_graph/optimization_problem_3d_test.cc b/cartographer/mapping/3d/pose_graph/optimization_problem_3d_test.cc
similarity index 99%
rename from cartographer/mapping_3d/pose_graph/optimization_problem_3d_test.cc
rename to cartographer/mapping/3d/pose_graph/optimization_problem_3d_test.cc
index 13a55e1..be329e9 100644
--- a/cartographer/mapping_3d/pose_graph/optimization_problem_3d_test.cc
+++ b/cartographer/mapping/3d/pose_graph/optimization_problem_3d_test.cc
@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-#include "cartographer/mapping_3d/pose_graph/optimization_problem_3d.h"
+#include "cartographer/mapping/3d/pose_graph/optimization_problem_3d.h"
 
 #include <random>
 
diff --git a/cartographer/mapping_3d/pose_graph/spa_cost_function_3d.h b/cartographer/mapping/3d/pose_graph/spa_cost_function_3d.h
similarity index 100%
rename from cartographer/mapping_3d/pose_graph/spa_cost_function_3d.h
rename to cartographer/mapping/3d/pose_graph/spa_cost_function_3d.h
diff --git a/cartographer/mapping_3d/pose_graph_3d.cc b/cartographer/mapping/3d/pose_graph_3d.cc
similarity index 99%
rename from cartographer/mapping_3d/pose_graph_3d.cc
rename to cartographer/mapping/3d/pose_graph_3d.cc
index 1df7216..3a99751 100644
--- a/cartographer/mapping_3d/pose_graph_3d.cc
+++ b/cartographer/mapping/3d/pose_graph_3d.cc
@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-#include "cartographer/mapping_3d/pose_graph_3d.h"
+#include "cartographer/mapping/3d/pose_graph_3d.h"
 
 #include <algorithm>
 #include <cmath>
diff --git a/cartographer/mapping_3d/pose_graph_3d.h b/cartographer/mapping/3d/pose_graph_3d.h
similarity index 98%
rename from cartographer/mapping_3d/pose_graph_3d.h
rename to cartographer/mapping/3d/pose_graph_3d.h
index 5bef40f..c426160 100644
--- a/cartographer/mapping_3d/pose_graph_3d.h
+++ b/cartographer/mapping/3d/pose_graph_3d.h
@@ -32,12 +32,12 @@
 #include "cartographer/common/mutex.h"
 #include "cartographer/common/thread_pool.h"
 #include "cartographer/common/time.h"
+#include "cartographer/mapping/3d/pose_graph/constraint_builder_3d.h"
+#include "cartographer/mapping/3d/pose_graph/optimization_problem_3d.h"
+#include "cartographer/mapping/3d/submap_3d.h"
 #include "cartographer/mapping/pose_graph.h"
 #include "cartographer/mapping/pose_graph_trimmer.h"
 #include "cartographer/mapping/trajectory_connectivity_state.h"
-#include "cartographer/mapping_3d/pose_graph/constraint_builder_3d.h"
-#include "cartographer/mapping_3d/pose_graph/optimization_problem_3d.h"
-#include "cartographer/mapping_3d/submap_3d.h"
 #include "cartographer/sensor/fixed_frame_pose_data.h"
 #include "cartographer/sensor/landmark_data.h"
 #include "cartographer/sensor/odometry_data.h"
diff --git a/cartographer/mapping_3d/proto/hybrid_grid.proto b/cartographer/mapping/3d/proto/hybrid_grid.proto
similarity index 100%
rename from cartographer/mapping_3d/proto/hybrid_grid.proto
rename to cartographer/mapping/3d/proto/hybrid_grid.proto
diff --git a/cartographer/mapping_3d/proto/local_trajectory_builder_options_3d.proto b/cartographer/mapping/3d/proto/local_trajectory_builder_options_3d.proto
similarity index 95%
rename from cartographer/mapping_3d/proto/local_trajectory_builder_options_3d.proto
rename to cartographer/mapping/3d/proto/local_trajectory_builder_options_3d.proto
index c173266..42d6b31 100644
--- a/cartographer/mapping_3d/proto/local_trajectory_builder_options_3d.proto
+++ b/cartographer/mapping/3d/proto/local_trajectory_builder_options_3d.proto
@@ -19,8 +19,8 @@ package cartographer.mapping.proto;
 import "cartographer/mapping/proto/motion_filter_options.proto";
 import "cartographer/sensor/proto/adaptive_voxel_filter_options.proto";
 import "cartographer/mapping/scan_matching/proto/real_time_correlative_scan_matcher_options.proto";
-import "cartographer/mapping_3d/proto/submaps_options_3d.proto";
-import "cartographer/mapping_3d/scan_matching/proto/ceres_scan_matcher_options_3d.proto";
+import "cartographer/mapping/3d/proto/submaps_options_3d.proto";
+import "cartographer/mapping/3d/scan_matching/proto/ceres_scan_matcher_options_3d.proto";
 
 // NEXT ID: 18
 message LocalTrajectoryBuilderOptions3D {
diff --git a/cartographer/mapping_3d/proto/range_data_inserter_options_3d.proto b/cartographer/mapping/3d/proto/range_data_inserter_options_3d.proto
similarity index 100%
rename from cartographer/mapping_3d/proto/range_data_inserter_options_3d.proto
rename to cartographer/mapping/3d/proto/range_data_inserter_options_3d.proto
diff --git a/cartographer/mapping_3d/proto/submaps_options_3d.proto b/cartographer/mapping/3d/proto/submaps_options_3d.proto
similarity index 95%
rename from cartographer/mapping_3d/proto/submaps_options_3d.proto
rename to cartographer/mapping/3d/proto/submaps_options_3d.proto
index cf703a7..27a6813 100644
--- a/cartographer/mapping_3d/proto/submaps_options_3d.proto
+++ b/cartographer/mapping/3d/proto/submaps_options_3d.proto
@@ -14,7 +14,7 @@
 
 syntax = "proto3";
 
-import "cartographer/mapping_3d/proto/range_data_inserter_options_3d.proto";
+import "cartographer/mapping/3d/proto/range_data_inserter_options_3d.proto";
 
 package cartographer.mapping.proto;
 
diff --git a/cartographer/mapping_3d/range_data_inserter_3d.cc b/cartographer/mapping/3d/range_data_inserter_3d.cc
similarity index 98%
rename from cartographer/mapping_3d/range_data_inserter_3d.cc
rename to cartographer/mapping/3d/range_data_inserter_3d.cc
index b601067..698ea2d 100644
--- a/cartographer/mapping_3d/range_data_inserter_3d.cc
+++ b/cartographer/mapping/3d/range_data_inserter_3d.cc
@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-#include "cartographer/mapping_3d/range_data_inserter_3d.h"
+#include "cartographer/mapping/3d/range_data_inserter_3d.h"
 
 #include "Eigen/Core"
 #include "cartographer/mapping/probability_values.h"
diff --git a/cartographer/mapping_3d/range_data_inserter_3d.h b/cartographer/mapping/3d/range_data_inserter_3d.h
similarity index 93%
rename from cartographer/mapping_3d/range_data_inserter_3d.h
rename to cartographer/mapping/3d/range_data_inserter_3d.h
index 9af26f5..524dbfa 100644
--- a/cartographer/mapping_3d/range_data_inserter_3d.h
+++ b/cartographer/mapping/3d/range_data_inserter_3d.h
@@ -17,8 +17,8 @@
 #ifndef CARTOGRAPHER_MAPPING_3D_RANGE_DATA_INSERTER_3D_H_
 #define CARTOGRAPHER_MAPPING_3D_RANGE_DATA_INSERTER_3D_H_
 
-#include "cartographer/mapping_3d/hybrid_grid.h"
-#include "cartographer/mapping_3d/proto/range_data_inserter_options_3d.pb.h"
+#include "cartographer/mapping/3d/hybrid_grid.h"
+#include "cartographer/mapping/3d/proto/range_data_inserter_options_3d.pb.h"
 #include "cartographer/sensor/point_cloud.h"
 #include "cartographer/sensor/range_data.h"
 
diff --git a/cartographer/mapping_3d/range_data_inserter_3d_test.cc b/cartographer/mapping/3d/range_data_inserter_3d_test.cc
similarity index 98%
rename from cartographer/mapping_3d/range_data_inserter_3d_test.cc
rename to cartographer/mapping/3d/range_data_inserter_3d_test.cc
index e652d30..68efcff 100644
--- a/cartographer/mapping_3d/range_data_inserter_3d_test.cc
+++ b/cartographer/mapping/3d/range_data_inserter_3d_test.cc
@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-#include "cartographer/mapping_3d/range_data_inserter_3d.h"
+#include "cartographer/mapping/3d/range_data_inserter_3d.h"
 
 #include <memory>
 #include <vector>
diff --git a/cartographer/mapping_3d/rotation_parameterization.h b/cartographer/mapping/3d/rotation_parameterization.h
similarity index 100%
rename from cartographer/mapping_3d/rotation_parameterization.h
rename to cartographer/mapping/3d/rotation_parameterization.h
diff --git a/cartographer/mapping_3d/scan_matching/ceres_scan_matcher_3d.cc b/cartographer/mapping/3d/scan_matching/ceres_scan_matcher_3d.cc
similarity index 93%
rename from cartographer/mapping_3d/scan_matching/ceres_scan_matcher_3d.cc
rename to cartographer/mapping/3d/scan_matching/ceres_scan_matcher_3d.cc
index c2904bc..217eaff 100644
--- a/cartographer/mapping_3d/scan_matching/ceres_scan_matcher_3d.cc
+++ b/cartographer/mapping/3d/scan_matching/ceres_scan_matcher_3d.cc
@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-#include "cartographer/mapping_3d/scan_matching/ceres_scan_matcher_3d.h"
+#include "cartographer/mapping/3d/scan_matching/ceres_scan_matcher_3d.h"
 
 #include <string>
 #include <utility>
@@ -22,11 +22,11 @@
 
 #include "cartographer/common/ceres_solver_options.h"
 #include "cartographer/common/make_unique.h"
-#include "cartographer/internal/mapping_3d/scan_matching/occupied_space_cost_function_3d.h"
+#include "cartographer/internal/mapping/3d/scan_matching/occupied_space_cost_function_3d.h"
+#include "cartographer/mapping/3d/rotation_parameterization.h"
+#include "cartographer/mapping/3d/scan_matching/rotation_delta_cost_functor_3d.h"
+#include "cartographer/mapping/3d/scan_matching/translation_delta_cost_functor_3d.h"
 #include "cartographer/mapping/pose_graph/ceres_pose.h"
-#include "cartographer/mapping_3d/rotation_parameterization.h"
-#include "cartographer/mapping_3d/scan_matching/rotation_delta_cost_functor_3d.h"
-#include "cartographer/mapping_3d/scan_matching/translation_delta_cost_functor_3d.h"
 #include "cartographer/transform/rigid_transform.h"
 #include "cartographer/transform/transform.h"
 #include "ceres/ceres.h"
diff --git a/cartographer/mapping_3d/scan_matching/ceres_scan_matcher_3d.h b/cartographer/mapping/3d/scan_matching/ceres_scan_matcher_3d.h
similarity index 95%
rename from cartographer/mapping_3d/scan_matching/ceres_scan_matcher_3d.h
rename to cartographer/mapping/3d/scan_matching/ceres_scan_matcher_3d.h
index 58708f7..63b1e3e 100644
--- a/cartographer/mapping_3d/scan_matching/ceres_scan_matcher_3d.h
+++ b/cartographer/mapping/3d/scan_matching/ceres_scan_matcher_3d.h
@@ -22,8 +22,8 @@
 
 #include "Eigen/Core"
 #include "cartographer/common/lua_parameter_dictionary.h"
-#include "cartographer/mapping_3d/hybrid_grid.h"
-#include "cartographer/mapping_3d/scan_matching/proto/ceres_scan_matcher_options_3d.pb.h"
+#include "cartographer/mapping/3d/hybrid_grid.h"
+#include "cartographer/mapping/3d/scan_matching/proto/ceres_scan_matcher_options_3d.pb.h"
 #include "cartographer/sensor/point_cloud.h"
 #include "cartographer/transform/rigid_transform.h"
 
diff --git a/cartographer/mapping_3d/scan_matching/ceres_scan_matcher_3d_test.cc b/cartographer/mapping/3d/scan_matching/ceres_scan_matcher_3d_test.cc
similarity index 97%
rename from cartographer/mapping_3d/scan_matching/ceres_scan_matcher_3d_test.cc
rename to cartographer/mapping/3d/scan_matching/ceres_scan_matcher_3d_test.cc
index 7b50c2e..f013ac2 100644
--- a/cartographer/mapping_3d/scan_matching/ceres_scan_matcher_3d_test.cc
+++ b/cartographer/mapping/3d/scan_matching/ceres_scan_matcher_3d_test.cc
@@ -14,13 +14,13 @@
  * limitations under the License.
  */
 
-#include "cartographer/mapping_3d/scan_matching/ceres_scan_matcher_3d.h"
+#include "cartographer/mapping/3d/scan_matching/ceres_scan_matcher_3d.h"
 
 #include <memory>
 
 #include "Eigen/Core"
 #include "cartographer/common/lua_parameter_dictionary_test_helpers.h"
-#include "cartographer/mapping_3d/hybrid_grid.h"
+#include "cartographer/mapping/3d/hybrid_grid.h"
 #include "cartographer/sensor/point_cloud.h"
 #include "cartographer/transform/rigid_transform.h"
 #include "cartographer/transform/rigid_transform_test_helpers.h"
diff --git a/cartographer/mapping_3d/scan_matching/fast_correlative_scan_matcher_3d.cc b/cartographer/mapping/3d/scan_matching/fast_correlative_scan_matcher_3d.cc
similarity index 98%
rename from cartographer/mapping_3d/scan_matching/fast_correlative_scan_matcher_3d.cc
rename to cartographer/mapping/3d/scan_matching/fast_correlative_scan_matcher_3d.cc
index 11c582e..ba020ab 100644
--- a/cartographer/mapping_3d/scan_matching/fast_correlative_scan_matcher_3d.cc
+++ b/cartographer/mapping/3d/scan_matching/fast_correlative_scan_matcher_3d.cc
@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-#include "cartographer/mapping_3d/scan_matching/fast_correlative_scan_matcher_3d.h"
+#include "cartographer/mapping/3d/scan_matching/fast_correlative_scan_matcher_3d.h"
 
 #include <algorithm>
 #include <cmath>
@@ -24,9 +24,9 @@
 #include "Eigen/Geometry"
 #include "cartographer/common/make_unique.h"
 #include "cartographer/common/math.h"
-#include "cartographer/mapping_3d/scan_matching/low_resolution_matcher.h"
-#include "cartographer/mapping_3d/scan_matching/precomputation_grid_3d.h"
-#include "cartographer/mapping_3d/scan_matching/proto/fast_correlative_scan_matcher_options_3d.pb.h"
+#include "cartographer/mapping/3d/scan_matching/low_resolution_matcher.h"
+#include "cartographer/mapping/3d/scan_matching/precomputation_grid_3d.h"
+#include "cartographer/mapping/3d/scan_matching/proto/fast_correlative_scan_matcher_options_3d.pb.h"
 #include "cartographer/transform/transform.h"
 #include "glog/logging.h"
 
diff --git a/cartographer/mapping_3d/scan_matching/fast_correlative_scan_matcher_3d.h b/cartographer/mapping/3d/scan_matching/fast_correlative_scan_matcher_3d.h
similarity index 96%
rename from cartographer/mapping_3d/scan_matching/fast_correlative_scan_matcher_3d.h
rename to cartographer/mapping/3d/scan_matching/fast_correlative_scan_matcher_3d.h
index ab14ea1..1f7b59d 100644
--- a/cartographer/mapping_3d/scan_matching/fast_correlative_scan_matcher_3d.h
+++ b/cartographer/mapping/3d/scan_matching/fast_correlative_scan_matcher_3d.h
@@ -25,11 +25,11 @@
 
 #include "Eigen/Core"
 #include "cartographer/common/port.h"
+#include "cartographer/mapping/2d/scan_matching/fast_correlative_scan_matcher_2d.h"
+#include "cartographer/mapping/3d/hybrid_grid.h"
+#include "cartographer/mapping/3d/scan_matching/proto/fast_correlative_scan_matcher_options_3d.pb.h"
+#include "cartographer/mapping/3d/scan_matching/rotational_scan_matcher.h"
 #include "cartographer/mapping/trajectory_node.h"
-#include "cartographer/mapping_2d/scan_matching/fast_correlative_scan_matcher_2d.h"
-#include "cartographer/mapping_3d/hybrid_grid.h"
-#include "cartographer/mapping_3d/scan_matching/proto/fast_correlative_scan_matcher_options_3d.pb.h"
-#include "cartographer/mapping_3d/scan_matching/rotational_scan_matcher.h"
 #include "cartographer/sensor/point_cloud.h"
 
 namespace cartographer {
diff --git a/cartographer/mapping_3d/scan_matching/fast_correlative_scan_matcher_3d_test.cc b/cartographer/mapping/3d/scan_matching/fast_correlative_scan_matcher_3d_test.cc
similarity index 98%
rename from cartographer/mapping_3d/scan_matching/fast_correlative_scan_matcher_3d_test.cc
rename to cartographer/mapping/3d/scan_matching/fast_correlative_scan_matcher_3d_test.cc
index 9b678c9..c60297e 100644
--- a/cartographer/mapping_3d/scan_matching/fast_correlative_scan_matcher_3d_test.cc
+++ b/cartographer/mapping/3d/scan_matching/fast_correlative_scan_matcher_3d_test.cc
@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-#include "cartographer/mapping_3d/scan_matching/fast_correlative_scan_matcher_3d.h"
+#include "cartographer/mapping/3d/scan_matching/fast_correlative_scan_matcher_3d.h"
 
 #include <algorithm>
 #include <cmath>
@@ -23,7 +23,7 @@
 
 #include "cartographer/common/lua_parameter_dictionary_test_helpers.h"
 #include "cartographer/common/make_unique.h"
-#include "cartographer/mapping_3d/range_data_inserter_3d.h"
+#include "cartographer/mapping/3d/range_data_inserter_3d.h"
 #include "cartographer/transform/rigid_transform_test_helpers.h"
 #include "cartographer/transform/transform.h"
 #include "gtest/gtest.h"
diff --git a/cartographer/mapping_3d/scan_matching/interpolated_grid.h b/cartographer/mapping/3d/scan_matching/interpolated_grid.h
similarity index 99%
rename from cartographer/mapping_3d/scan_matching/interpolated_grid.h
rename to cartographer/mapping/3d/scan_matching/interpolated_grid.h
index e88e508..3d11cff 100644
--- a/cartographer/mapping_3d/scan_matching/interpolated_grid.h
+++ b/cartographer/mapping/3d/scan_matching/interpolated_grid.h
@@ -19,7 +19,7 @@
 
 #include <cmath>
 
-#include "cartographer/mapping_3d/hybrid_grid.h"
+#include "cartographer/mapping/3d/hybrid_grid.h"
 
 namespace cartographer {
 namespace mapping {
diff --git a/cartographer/mapping_3d/scan_matching/interpolated_grid_test.cc b/cartographer/mapping/3d/scan_matching/interpolated_grid_test.cc
similarity index 96%
rename from cartographer/mapping_3d/scan_matching/interpolated_grid_test.cc
rename to cartographer/mapping/3d/scan_matching/interpolated_grid_test.cc
index 4981d14..f3bbbf3 100644
--- a/cartographer/mapping_3d/scan_matching/interpolated_grid_test.cc
+++ b/cartographer/mapping/3d/scan_matching/interpolated_grid_test.cc
@@ -14,10 +14,10 @@
  * limitations under the License.
  */
 
-#include "cartographer/mapping_3d/scan_matching/interpolated_grid.h"
+#include "cartographer/mapping/3d/scan_matching/interpolated_grid.h"
 
 #include "Eigen/Core"
-#include "cartographer/mapping_3d/hybrid_grid.h"
+#include "cartographer/mapping/3d/hybrid_grid.h"
 #include "gtest/gtest.h"
 
 namespace cartographer {
diff --git a/cartographer/mapping_3d/scan_matching/low_resolution_matcher.cc b/cartographer/mapping/3d/scan_matching/low_resolution_matcher.cc
similarity index 95%
rename from cartographer/mapping_3d/scan_matching/low_resolution_matcher.cc
rename to cartographer/mapping/3d/scan_matching/low_resolution_matcher.cc
index f9cfd39..c8bebe1 100644
--- a/cartographer/mapping_3d/scan_matching/low_resolution_matcher.cc
+++ b/cartographer/mapping/3d/scan_matching/low_resolution_matcher.cc
@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-#include "cartographer/mapping_3d/scan_matching/low_resolution_matcher.h"
+#include "cartographer/mapping/3d/scan_matching/low_resolution_matcher.h"
 
 namespace cartographer {
 namespace mapping {
diff --git a/cartographer/mapping_3d/scan_matching/low_resolution_matcher.h b/cartographer/mapping/3d/scan_matching/low_resolution_matcher.h
similarity index 96%
rename from cartographer/mapping_3d/scan_matching/low_resolution_matcher.h
rename to cartographer/mapping/3d/scan_matching/low_resolution_matcher.h
index 2bf23e3..f202140 100644
--- a/cartographer/mapping_3d/scan_matching/low_resolution_matcher.h
+++ b/cartographer/mapping/3d/scan_matching/low_resolution_matcher.h
@@ -19,7 +19,7 @@
 
 #include <functional>
 
-#include "cartographer/mapping_3d/hybrid_grid.h"
+#include "cartographer/mapping/3d/hybrid_grid.h"
 #include "cartographer/sensor/point_cloud.h"
 #include "cartographer/transform/rigid_transform.h"
 
diff --git a/cartographer/mapping_3d/scan_matching/precomputation_grid_3d.cc b/cartographer/mapping/3d/scan_matching/precomputation_grid_3d.cc
similarity index 98%
rename from cartographer/mapping_3d/scan_matching/precomputation_grid_3d.cc
rename to cartographer/mapping/3d/scan_matching/precomputation_grid_3d.cc
index 614be10..ecf014c 100644
--- a/cartographer/mapping_3d/scan_matching/precomputation_grid_3d.cc
+++ b/cartographer/mapping/3d/scan_matching/precomputation_grid_3d.cc
@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-#include "cartographer/mapping_3d/scan_matching/precomputation_grid_3d.h"
+#include "cartographer/mapping/3d/scan_matching/precomputation_grid_3d.h"
 
 #include <algorithm>
 
diff --git a/cartographer/mapping_3d/scan_matching/precomputation_grid_3d.h b/cartographer/mapping/3d/scan_matching/precomputation_grid_3d.h
similarity index 97%
rename from cartographer/mapping_3d/scan_matching/precomputation_grid_3d.h
rename to cartographer/mapping/3d/scan_matching/precomputation_grid_3d.h
index f1d8686..a1dc68c 100644
--- a/cartographer/mapping_3d/scan_matching/precomputation_grid_3d.h
+++ b/cartographer/mapping/3d/scan_matching/precomputation_grid_3d.h
@@ -17,7 +17,7 @@
 #ifndef CARTOGRAPHER_MAPPING_3D_SCAN_MATCHING_PRECOMPUTATION_GRID_3D_H_
 #define CARTOGRAPHER_MAPPING_3D_SCAN_MATCHING_PRECOMPUTATION_GRID_3D_H_
 
-#include "cartographer/mapping_3d/hybrid_grid.h"
+#include "cartographer/mapping/3d/hybrid_grid.h"
 
 namespace cartographer {
 namespace mapping {
diff --git a/cartographer/mapping_3d/scan_matching/precomputation_grid_3d_test.cc b/cartographer/mapping/3d/scan_matching/precomputation_grid_3d_test.cc
similarity index 96%
rename from cartographer/mapping_3d/scan_matching/precomputation_grid_3d_test.cc
rename to cartographer/mapping/3d/scan_matching/precomputation_grid_3d_test.cc
index 3f2463e..749b3b3 100644
--- a/cartographer/mapping_3d/scan_matching/precomputation_grid_3d_test.cc
+++ b/cartographer/mapping/3d/scan_matching/precomputation_grid_3d_test.cc
@@ -14,13 +14,13 @@
  * limitations under the License.
  */
 
-#include "cartographer/mapping_3d/scan_matching/precomputation_grid_3d.h"
+#include "cartographer/mapping/3d/scan_matching/precomputation_grid_3d.h"
 
 #include <random>
 #include <tuple>
 #include <vector>
 
-#include "cartographer/mapping_3d/hybrid_grid.h"
+#include "cartographer/mapping/3d/hybrid_grid.h"
 #include "gmock/gmock.h"
 
 namespace cartographer {
diff --git a/cartographer/mapping_3d/scan_matching/proto/ceres_scan_matcher_options_3d.proto b/cartographer/mapping/3d/scan_matching/proto/ceres_scan_matcher_options_3d.proto
similarity index 100%
rename from cartographer/mapping_3d/scan_matching/proto/ceres_scan_matcher_options_3d.proto
rename to cartographer/mapping/3d/scan_matching/proto/ceres_scan_matcher_options_3d.proto
diff --git a/cartographer/mapping_3d/scan_matching/proto/fast_correlative_scan_matcher_options_3d.proto b/cartographer/mapping/3d/scan_matching/proto/fast_correlative_scan_matcher_options_3d.proto
similarity index 100%
rename from cartographer/mapping_3d/scan_matching/proto/fast_correlative_scan_matcher_options_3d.proto
rename to cartographer/mapping/3d/scan_matching/proto/fast_correlative_scan_matcher_options_3d.proto
diff --git a/cartographer/mapping_3d/scan_matching/real_time_correlative_scan_matcher_3d.cc b/cartographer/mapping/3d/scan_matching/real_time_correlative_scan_matcher_3d.cc
similarity index 98%
rename from cartographer/mapping_3d/scan_matching/real_time_correlative_scan_matcher_3d.cc
rename to cartographer/mapping/3d/scan_matching/real_time_correlative_scan_matcher_3d.cc
index 482e1e9..14b74c9 100644
--- a/cartographer/mapping_3d/scan_matching/real_time_correlative_scan_matcher_3d.cc
+++ b/cartographer/mapping/3d/scan_matching/real_time_correlative_scan_matcher_3d.cc
@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-#include "cartographer/mapping_3d/scan_matching/real_time_correlative_scan_matcher_3d.h"
+#include "cartographer/mapping/3d/scan_matching/real_time_correlative_scan_matcher_3d.h"
 
 #include <cmath>
 
diff --git a/cartographer/mapping_3d/scan_matching/real_time_correlative_scan_matcher_3d.h b/cartographer/mapping/3d/scan_matching/real_time_correlative_scan_matcher_3d.h
similarity index 98%
rename from cartographer/mapping_3d/scan_matching/real_time_correlative_scan_matcher_3d.h
rename to cartographer/mapping/3d/scan_matching/real_time_correlative_scan_matcher_3d.h
index bdedfc6..f955d73 100644
--- a/cartographer/mapping_3d/scan_matching/real_time_correlative_scan_matcher_3d.h
+++ b/cartographer/mapping/3d/scan_matching/real_time_correlative_scan_matcher_3d.h
@@ -20,8 +20,8 @@
 #include <vector>
 
 #include "Eigen/Core"
+#include "cartographer/mapping/3d/hybrid_grid.h"
 #include "cartographer/mapping/scan_matching/proto/real_time_correlative_scan_matcher_options.pb.h"
-#include "cartographer/mapping_3d/hybrid_grid.h"
 #include "cartographer/sensor/point_cloud.h"
 
 namespace cartographer {
diff --git a/cartographer/mapping_3d/scan_matching/real_time_correlative_scan_matcher_3d_test.cc b/cartographer/mapping/3d/scan_matching/real_time_correlative_scan_matcher_3d_test.cc
similarity index 95%
rename from cartographer/mapping_3d/scan_matching/real_time_correlative_scan_matcher_3d_test.cc
rename to cartographer/mapping/3d/scan_matching/real_time_correlative_scan_matcher_3d_test.cc
index d94675b..f473a7b 100644
--- a/cartographer/mapping_3d/scan_matching/real_time_correlative_scan_matcher_3d_test.cc
+++ b/cartographer/mapping/3d/scan_matching/real_time_correlative_scan_matcher_3d_test.cc
@@ -14,14 +14,14 @@
  * limitations under the License.
  */
 
-#include "cartographer/mapping_3d/scan_matching/real_time_correlative_scan_matcher_3d.h"
+#include "cartographer/mapping/3d/scan_matching/real_time_correlative_scan_matcher_3d.h"
 
 #include <memory>
 
 #include "Eigen/Core"
 #include "cartographer/common/lua_parameter_dictionary_test_helpers.h"
-#include "cartographer/mapping_2d/scan_matching/real_time_correlative_scan_matcher_2d.h"
-#include "cartographer/mapping_3d/hybrid_grid.h"
+#include "cartographer/mapping/2d/scan_matching/real_time_correlative_scan_matcher_2d.h"
+#include "cartographer/mapping/3d/hybrid_grid.h"
 #include "cartographer/sensor/point_cloud.h"
 #include "cartographer/transform/rigid_transform.h"
 #include "cartographer/transform/rigid_transform_test_helpers.h"
diff --git a/cartographer/mapping_3d/scan_matching/rotation_delta_cost_functor_3d.h b/cartographer/mapping/3d/scan_matching/rotation_delta_cost_functor_3d.h
similarity index 100%
rename from cartographer/mapping_3d/scan_matching/rotation_delta_cost_functor_3d.h
rename to cartographer/mapping/3d/scan_matching/rotation_delta_cost_functor_3d.h
diff --git a/cartographer/mapping_3d/scan_matching/rotation_delta_cost_functor_3d_test.cc b/cartographer/mapping/3d/scan_matching/rotation_delta_cost_functor_3d_test.cc
similarity index 98%
rename from cartographer/mapping_3d/scan_matching/rotation_delta_cost_functor_3d_test.cc
rename to cartographer/mapping/3d/scan_matching/rotation_delta_cost_functor_3d_test.cc
index fe4bf90..18d9328 100644
--- a/cartographer/mapping_3d/scan_matching/rotation_delta_cost_functor_3d_test.cc
+++ b/cartographer/mapping/3d/scan_matching/rotation_delta_cost_functor_3d_test.cc
@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-#include "cartographer/mapping_3d/scan_matching/rotation_delta_cost_functor_3d.h"
+#include "cartographer/mapping/3d/scan_matching/rotation_delta_cost_functor_3d.h"
 
 #include "gtest/gtest.h"
 
diff --git a/cartographer/mapping_3d/scan_matching/rotational_scan_matcher.cc b/cartographer/mapping/3d/scan_matching/rotational_scan_matcher.cc
similarity index 99%
rename from cartographer/mapping_3d/scan_matching/rotational_scan_matcher.cc
rename to cartographer/mapping/3d/scan_matching/rotational_scan_matcher.cc
index b3ebd04..348a77e 100644
--- a/cartographer/mapping_3d/scan_matching/rotational_scan_matcher.cc
+++ b/cartographer/mapping/3d/scan_matching/rotational_scan_matcher.cc
@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-#include "cartographer/mapping_3d/scan_matching/rotational_scan_matcher.h"
+#include "cartographer/mapping/3d/scan_matching/rotational_scan_matcher.h"
 
 #include <map>
 #include <vector>
diff --git a/cartographer/mapping_3d/scan_matching/rotational_scan_matcher.h b/cartographer/mapping/3d/scan_matching/rotational_scan_matcher.h
similarity index 100%
rename from cartographer/mapping_3d/scan_matching/rotational_scan_matcher.h
rename to cartographer/mapping/3d/scan_matching/rotational_scan_matcher.h
diff --git a/cartographer/mapping_3d/scan_matching/rotational_scan_matcher_test.cc b/cartographer/mapping/3d/scan_matching/rotational_scan_matcher_test.cc
similarity index 97%
rename from cartographer/mapping_3d/scan_matching/rotational_scan_matcher_test.cc
rename to cartographer/mapping/3d/scan_matching/rotational_scan_matcher_test.cc
index 077ba7a..fabebc7 100644
--- a/cartographer/mapping_3d/scan_matching/rotational_scan_matcher_test.cc
+++ b/cartographer/mapping/3d/scan_matching/rotational_scan_matcher_test.cc
@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-#include "cartographer/mapping_3d/scan_matching/rotational_scan_matcher.h"
+#include "cartographer/mapping/3d/scan_matching/rotational_scan_matcher.h"
 
 #include <cmath>
 
diff --git a/cartographer/mapping_3d/scan_matching/translation_delta_cost_functor_3d.h b/cartographer/mapping/3d/scan_matching/translation_delta_cost_functor_3d.h
similarity index 100%
rename from cartographer/mapping_3d/scan_matching/translation_delta_cost_functor_3d.h
rename to cartographer/mapping/3d/scan_matching/translation_delta_cost_functor_3d.h
diff --git a/cartographer/mapping_3d/submap_3d.cc b/cartographer/mapping/3d/submap_3d.cc
similarity index 99%
rename from cartographer/mapping_3d/submap_3d.cc
rename to cartographer/mapping/3d/submap_3d.cc
index 02e590a..816de4a 100644
--- a/cartographer/mapping_3d/submap_3d.cc
+++ b/cartographer/mapping/3d/submap_3d.cc
@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-#include "cartographer/mapping_3d/submap_3d.h"
+#include "cartographer/mapping/3d/submap_3d.h"
 
 #include <cmath>
 #include <limits>
diff --git a/cartographer/mapping_3d/submap_3d.h b/cartographer/mapping/3d/submap_3d.h
similarity index 95%
rename from cartographer/mapping_3d/submap_3d.h
rename to cartographer/mapping/3d/submap_3d.h
index 153b888..5a1367f 100644
--- a/cartographer/mapping_3d/submap_3d.h
+++ b/cartographer/mapping/3d/submap_3d.h
@@ -23,13 +23,13 @@
 
 #include "Eigen/Geometry"
 #include "cartographer/common/port.h"
+#include "cartographer/mapping/3d/hybrid_grid.h"
+#include "cartographer/mapping/3d/proto/submaps_options_3d.pb.h"
+#include "cartographer/mapping/3d/range_data_inserter_3d.h"
 #include "cartographer/mapping/id.h"
 #include "cartographer/mapping/proto/serialization.pb.h"
 #include "cartographer/mapping/proto/submap_visualization.pb.h"
 #include "cartographer/mapping/submaps.h"
-#include "cartographer/mapping_3d/hybrid_grid.h"
-#include "cartographer/mapping_3d/proto/submaps_options_3d.pb.h"
-#include "cartographer/mapping_3d/range_data_inserter_3d.h"
 #include "cartographer/sensor/range_data.h"
 #include "cartographer/transform/rigid_transform.h"
 #include "cartographer/transform/transform.h"
diff --git a/cartographer/mapping_3d/submap_3d_test.cc b/cartographer/mapping/3d/submap_3d_test.cc
similarity index 97%
rename from cartographer/mapping_3d/submap_3d_test.cc
rename to cartographer/mapping/3d/submap_3d_test.cc
index e272e31..b16fd41 100644
--- a/cartographer/mapping_3d/submap_3d_test.cc
+++ b/cartographer/mapping/3d/submap_3d_test.cc
@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-#include "cartographer/mapping_3d/submap_3d.h"
+#include "cartographer/mapping/3d/submap_3d.h"
 
 #include "cartographer/transform/transform.h"
 #include "gmock/gmock.h"
diff --git a/cartographer/mapping/local_slam_result_data.h b/cartographer/mapping/local_slam_result_data.h
index 4bb9880..fa89ead 100644
--- a/cartographer/mapping/local_slam_result_data.h
+++ b/cartographer/mapping/local_slam_result_data.h
@@ -17,8 +17,8 @@
 #ifndef CARTOGRAPHER_MAPPING_LOCAL_SLAM_RESULT_DATA_H
 #define CARTOGRAPHER_MAPPING_LOCAL_SLAM_RESULT_DATA_H
 
-#include "cartographer/mapping_2d/pose_graph_2d.h"
-#include "cartographer/mapping_3d/pose_graph_3d.h"
+#include "cartographer/mapping/2d/pose_graph_2d.h"
+#include "cartographer/mapping/3d/pose_graph_3d.h"
 #include "cartographer/sensor/data.h"
 
 namespace cartographer {
diff --git a/cartographer/mapping/map_builder.cc b/cartographer/mapping/map_builder.cc
index 99a5b17..229f859 100644
--- a/cartographer/mapping/map_builder.cc
+++ b/cartographer/mapping/map_builder.cc
@@ -24,9 +24,9 @@
 
 #include "cartographer/common/make_unique.h"
 #include "cartographer/common/time.h"
+#include "cartographer/internal/mapping/2d/local_trajectory_builder_2d.h"
+#include "cartographer/internal/mapping/3d/local_trajectory_builder_3d.h"
 #include "cartographer/internal/mapping/global_trajectory_builder.h"
-#include "cartographer/internal/mapping_2d/local_trajectory_builder_2d.h"
-#include "cartographer/internal/mapping_3d/local_trajectory_builder_3d.h"
 #include "cartographer/mapping/collated_trajectory_builder.h"
 #include "cartographer/sensor/collator.h"
 #include "cartographer/sensor/range_data.h"
diff --git a/cartographer/mapping/map_builder.h b/cartographer/mapping/map_builder.h
index 02a2690..3609d4c 100644
--- a/cartographer/mapping/map_builder.h
+++ b/cartographer/mapping/map_builder.h
@@ -23,9 +23,9 @@
 #include <set>
 
 #include "cartographer/common/thread_pool.h"
+#include "cartographer/mapping/2d/pose_graph_2d.h"
+#include "cartographer/mapping/3d/pose_graph_3d.h"
 #include "cartographer/mapping/proto/map_builder_options.pb.h"
-#include "cartographer/mapping_2d/pose_graph_2d.h"
-#include "cartographer/mapping_3d/pose_graph_3d.h"
 #include "cartographer/sensor/collator_interface.h"
 
 namespace cartographer {
diff --git a/cartographer/mapping/pose_graph/constraint_builder.cc b/cartographer/mapping/pose_graph/constraint_builder.cc
index cec0e2e..fec217e 100644
--- a/cartographer/mapping/pose_graph/constraint_builder.cc
+++ b/cartographer/mapping/pose_graph/constraint_builder.cc
@@ -16,10 +16,10 @@
 
 #include "cartographer/mapping/pose_graph/constraint_builder.h"
 
-#include "cartographer/mapping_2d/scan_matching/ceres_scan_matcher_2d.h"
-#include "cartographer/mapping_2d/scan_matching/fast_correlative_scan_matcher_2d.h"
-#include "cartographer/mapping_3d/scan_matching/ceres_scan_matcher_3d.h"
-#include "cartographer/mapping_3d/scan_matching/fast_correlative_scan_matcher_3d.h"
+#include "cartographer/mapping/2d/scan_matching/ceres_scan_matcher_2d.h"
+#include "cartographer/mapping/2d/scan_matching/fast_correlative_scan_matcher_2d.h"
+#include "cartographer/mapping/3d/scan_matching/ceres_scan_matcher_3d.h"
+#include "cartographer/mapping/3d/scan_matching/fast_correlative_scan_matcher_3d.h"
 #include "cartographer/sensor/voxel_filter.h"
 
 namespace cartographer {
diff --git a/cartographer/mapping/pose_graph/proto/constraint_builder_options.proto b/cartographer/mapping/pose_graph/proto/constraint_builder_options.proto
index 594a4c6..13f8f38 100644
--- a/cartographer/mapping/pose_graph/proto/constraint_builder_options.proto
+++ b/cartographer/mapping/pose_graph/proto/constraint_builder_options.proto
@@ -16,10 +16,10 @@ syntax = "proto3";
 
 package cartographer.mapping.pose_graph.proto;
 
-import "cartographer/mapping_2d/scan_matching/proto/ceres_scan_matcher_options_2d.proto";
-import "cartographer/mapping_2d/scan_matching/proto/fast_correlative_scan_matcher_options_2d.proto";
-import "cartographer/mapping_3d/scan_matching/proto/ceres_scan_matcher_options_3d.proto";
-import "cartographer/mapping_3d/scan_matching/proto/fast_correlative_scan_matcher_options_3d.proto";
+import "cartographer/mapping/2d/scan_matching/proto/ceres_scan_matcher_options_2d.proto";
+import "cartographer/mapping/2d/scan_matching/proto/fast_correlative_scan_matcher_options_2d.proto";
+import "cartographer/mapping/3d/scan_matching/proto/ceres_scan_matcher_options_3d.proto";
+import "cartographer/mapping/3d/scan_matching/proto/fast_correlative_scan_matcher_options_3d.proto";
 
 message ConstraintBuilderOptions {
   // A constraint will be added if the proportion of added constraints to
diff --git a/cartographer/mapping/proto/submap.proto b/cartographer/mapping/proto/submap.proto
index 09fbbab..48db24d 100644
--- a/cartographer/mapping/proto/submap.proto
+++ b/cartographer/mapping/proto/submap.proto
@@ -16,8 +16,8 @@ syntax = "proto3";
 
 package cartographer.mapping.proto;
 
-import "cartographer/mapping_2d/proto/probability_grid.proto";
-import "cartographer/mapping_3d/proto/hybrid_grid.proto";
+import "cartographer/mapping/2d/proto/probability_grid.proto";
+import "cartographer/mapping/3d/proto/hybrid_grid.proto";
 import "cartographer/transform/proto/transform.proto";
 
 // Serialized state of a Submap2D.
diff --git a/cartographer/mapping/proto/trajectory_builder_options.proto b/cartographer/mapping/proto/trajectory_builder_options.proto
index 08c4ebf..4967e8c 100644
--- a/cartographer/mapping/proto/trajectory_builder_options.proto
+++ b/cartographer/mapping/proto/trajectory_builder_options.proto
@@ -15,8 +15,8 @@
 syntax = "proto3";
 
 import "cartographer/transform/proto/transform.proto";
-import "cartographer/mapping_2d/proto/local_trajectory_builder_options_2d.proto";
-import "cartographer/mapping_3d/proto/local_trajectory_builder_options_3d.proto";
+import "cartographer/mapping/2d/proto/local_trajectory_builder_options_2d.proto";
+import "cartographer/mapping/3d/proto/local_trajectory_builder_options_3d.proto";
 
 package cartographer.mapping.proto;
 
diff --git a/cartographer/mapping/submaps.h b/cartographer/mapping/submaps.h
index dd77f5a..c92a951 100644
--- a/cartographer/mapping/submaps.h
+++ b/cartographer/mapping/submaps.h
@@ -23,12 +23,12 @@
 #include "Eigen/Geometry"
 #include "cartographer/common/math.h"
 #include "cartographer/common/port.h"
+#include "cartographer/mapping/2d/probability_grid.h"
 #include "cartographer/mapping/id.h"
 #include "cartographer/mapping/probability_values.h"
 #include "cartographer/mapping/proto/serialization.pb.h"
 #include "cartographer/mapping/proto/submap_visualization.pb.h"
 #include "cartographer/mapping/trajectory_node.h"
-#include "cartographer/mapping_2d/probability_grid.h"
 #include "glog/logging.h"
 
 namespace cartographer {
diff --git a/cartographer/mapping/trajectory_builder_interface.cc b/cartographer/mapping/trajectory_builder_interface.cc
index 1f0c13c..ff5ce79 100644
--- a/cartographer/mapping/trajectory_builder_interface.cc
+++ b/cartographer/mapping/trajectory_builder_interface.cc
@@ -16,9 +16,9 @@
 
 #include "cartographer/mapping/trajectory_builder_interface.h"
 
+#include "cartographer/mapping/2d/local_trajectory_builder_options_2d.h"
+#include "cartographer/mapping/3d/local_trajectory_builder_options_3d.h"
 #include "cartographer/mapping/local_slam_result_data.h"
-#include "cartographer/mapping_2d/local_trajectory_builder_options_2d.h"
-#include "cartographer/mapping_3d/local_trajectory_builder_options_3d.h"
 
 namespace cartographer {
 namespace mapping {
diff --git a/cartographer/metrics/register.cc b/cartographer/metrics/register.cc
index 0e690c6..9b7e1a3 100644
--- a/cartographer/metrics/register.cc
+++ b/cartographer/metrics/register.cc
@@ -16,8 +16,8 @@
 
 #include "cartographer/metrics/register.h"
 
-#include "cartographer/mapping_2d/pose_graph/constraint_builder_2d.h"
-#include "cartographer/mapping_3d/pose_graph/constraint_builder_3d.h"
+#include "cartographer/mapping/2d/pose_graph/constraint_builder_2d.h"
+#include "cartographer/mapping/3d/pose_graph/constraint_builder_3d.h"
 
 namespace cartographer {
 namespace metrics {
diff --git a/cartographer/sensor/compressed_point_cloud.cc b/cartographer/sensor/compressed_point_cloud.cc
index 63f03d6..8e52f91 100644
--- a/cartographer/sensor/compressed_point_cloud.cc
+++ b/cartographer/sensor/compressed_point_cloud.cc
@@ -19,7 +19,7 @@
 #include <limits>
 
 #include "cartographer/common/math.h"
-#include "cartographer/mapping_3d/hybrid_grid.h"
+#include "cartographer/mapping/3d/hybrid_grid.h"
 
 namespace cartographer {
 namespace sensor {
diff --git a/cartographer/sensor/voxel_filter.h b/cartographer/sensor/voxel_filter.h
index da7d192..0470b0b 100644
--- a/cartographer/sensor/voxel_filter.h
+++ b/cartographer/sensor/voxel_filter.h
@@ -18,7 +18,7 @@
 #define CARTOGRAPHER_SENSOR_VOXEL_FILTER_H_
 
 #include "cartographer/common/lua_parameter_dictionary.h"
-#include "cartographer/mapping_3d/hybrid_grid.h"
+#include "cartographer/mapping/3d/hybrid_grid.h"
 #include "cartographer/sensor/point_cloud.h"
 #include "cartographer/sensor/proto/adaptive_voxel_filter_options.pb.h"
 
diff --git a/cartographer_grpc/map_builder_context.h b/cartographer_grpc/map_builder_context.h
index 411ee05..b9018e9 100644
--- a/cartographer_grpc/map_builder_context.h
+++ b/cartographer_grpc/map_builder_context.h
@@ -17,8 +17,8 @@
 #ifndef CARTOGRAPHER_GRPC_MAP_BUILDER_CONTEXT_H
 #define CARTOGRAPHER_GRPC_MAP_BUILDER_CONTEXT_H
 
-#include "cartographer/mapping_2d/submap_2d.h"
-#include "cartographer/mapping_3d/submap_3d.h"
+#include "cartographer/mapping/2d/submap_2d.h"
+#include "cartographer/mapping/3d/submap_3d.h"
 #include "cartographer_grpc/map_builder_context_interface.h"
 
 namespace cartographer_grpc {