Adds publishing of the scan matched point could. (#53)

cartographer_ros/configuration_files/demo_2d.rviz

@@ -19,8 +19,9 @@ Panels:
     Property Tree Widget:
       Expanded:
         - /Submaps1
+        - /PointCloud21
       Splitter Ratio: 0.600671
-    Tree Height: 817
+    Tree Height: 821
   - Class: rviz/Selection
     Name: Selection
   - Class: rviz/Tool Properties
@@ -39,7 +40,7 @@ Panels:
     Experimental: false
     Name: Time
     SyncMode: 0
-    SyncSource: ""
+    SyncSource: PointCloud2
 Visualization Manager:
   Class: ""
   Displays:
@@ -139,6 +140,36 @@ Visualization Manager:
       Tracking frame: base_link
       Unreliable: false
       Value: true
+    - Alpha: 1
+      Autocompute Intensity Bounds: true
+      Autocompute Value Bounds:
+        Max Value: 10
+        Min Value: -10
+        Value: true
+      Axis: Z
+      Channel Name: intensity
+      Class: rviz/PointCloud2
+      Color: 0; 255; 0
+      Color Transformer: FlatColor
+      Decay Time: 0
+      Enabled: true
+      Invert Rainbow: false
+      Max Color: 255; 255; 255
+      Max Intensity: 4096
+      Min Color: 0; 0; 0
+      Min Intensity: 0
+      Name: PointCloud2
+      Position Transformer: XYZ
+      Queue Size: 10
+      Selectable: true
+      Size (Pixels): 3
+      Size (m): 0.05
+      Style: Flat Squares
+      Topic: /scan_matched_points2
+      Unreliable: false
+      Use Fixed Frame: true
+      Use rainbow: true
+      Value: true
   Enabled: true
   Global Options:
     Background Color: 100; 100; 100

cartographer_ros/configuration_files/demo_3d.rviz

@@ -202,6 +202,36 @@ Visualization Manager:
       Tracking frame: base_link
       Unreliable: false
       Value: true
+    - Alpha: 1
+      Autocompute Intensity Bounds: true
+      Autocompute Value Bounds:
+        Max Value: 8.77916
+        Min Value: 4.51287
+        Value: true
+      Axis: Z
+      Channel Name: intensity
+      Class: rviz/PointCloud2
+      Color: 0; 255; 0
+      Color Transformer: AxisColor
+      Decay Time: 0
+      Enabled: false
+      Invert Rainbow: false
+      Max Color: 255; 255; 255
+      Max Intensity: 4096
+      Min Color: 0; 0; 0
+      Min Intensity: 0
+      Name: PointCloud2
+      Position Transformer: XYZ
+      Queue Size: 20
+      Selectable: true
+      Size (Pixels): 3
+      Size (m): 0.05
+      Style: Flat Squares
+      Topic: /scan_matched_points2
+      Unreliable: false
+      Use Fixed Frame: true
+      Use rainbow: true
+      Value: false
   Enabled: true
   Global Options:
     Background Color: 100; 100; 100

cartographer_ros/configuration_files/demo_turtlebot.rviz

@@ -0,0 +1,317 @@
+# Copyright 2016 The Cartographer Authors
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+Panels:
+  - Class: rviz/Displays
+    Help Height: 78
+    Name: Displays
+    Property Tree Widget:
+      Expanded:
+        - /Submaps1
+        - /PointCloud21
+      Splitter Ratio: 0.600671
+    Tree Height: 821
+  - Class: rviz/Selection
+    Name: Selection
+  - Class: rviz/Tool Properties
+    Expanded:
+      - /2D Pose Estimate1
+      - /2D Nav Goal1
+      - /Publish Point1
+    Name: Tool Properties
+    Splitter Ratio: 0.588679
+  - Class: rviz/Views
+    Expanded:
+      - /Current View1
+    Name: Views
+    Splitter Ratio: 0.5
+  - Class: rviz/Time
+    Experimental: false
+    Name: Time
+    SyncMode: 0
+    SyncSource: PointCloud2
+Visualization Manager:
+  Class: ""
+  Displays:
+    - Alpha: 0.5
+      Cell Size: 1
+      Class: rviz/Grid
+      Color: 160; 160; 164
+      Enabled: true
+      Line Style:
+        Line Width: 0.03
+        Value: Lines
+      Name: Grid
+      Normal Cell Count: 0
+      Offset:
+        X: 0
+        Y: 0
+        Z: 0
+      Plane: XY
+      Plane Cell Count: 100
+      Reference Frame: <Fixed Frame>
+      Value: true
+    - Class: rviz/TF
+      Enabled: true
+      Frame Timeout: 15
+      Frames:
+        All Enabled: true
+        base_footprint:
+          Value: true
+        base_link:
+          Value: true
+        camera_depth_frame:
+          Value: true
+        camera_depth_optical_frame:
+          Value: true
+        camera_link:
+          Value: true
+        camera_rgb_frame:
+          Value: true
+        camera_rgb_optical_frame:
+          Value: true
+        caster_back_link:
+          Value: true
+        caster_front_link:
+          Value: true
+        cliff_sensor_front_link:
+          Value: true
+        cliff_sensor_left_link:
+          Value: true
+        cliff_sensor_right_link:
+          Value: true
+        gyro_link:
+          Value: true
+        laser:
+          Value: true
+        laser_mount_link:
+          Value: true
+        map:
+          Value: true
+        odom:
+          Value: true
+        plate_bottom_link:
+          Value: true
+        plate_middle_link:
+          Value: true
+        plate_top_link:
+          Value: true
+        pole_bottom_0_link:
+          Value: true
+        pole_bottom_1_link:
+          Value: true
+        pole_bottom_2_link:
+          Value: true
+        pole_bottom_3_link:
+          Value: true
+        pole_bottom_4_link:
+          Value: true
+        pole_bottom_5_link:
+          Value: true
+        pole_kinect_0_link:
+          Value: true
+        pole_kinect_1_link:
+          Value: true
+        pole_middle_0_link:
+          Value: true
+        pole_middle_1_link:
+          Value: true
+        pole_middle_2_link:
+          Value: true
+        pole_middle_3_link:
+          Value: true
+        pole_top_0_link:
+          Value: true
+        pole_top_1_link:
+          Value: true
+        pole_top_2_link:
+          Value: true
+        pole_top_3_link:
+          Value: true
+        wheel_left_link:
+          Value: true
+        wheel_right_link:
+          Value: true
+      Marker Scale: 1
+      Name: TF
+      Show Arrows: true
+      Show Axes: true
+      Show Names: true
+      Tree:
+        map:
+          odom:
+            base_footprint:
+              base_link:
+                camera_rgb_frame:
+                  camera_depth_frame:
+                    camera_depth_optical_frame:
+                      {}
+                  camera_link:
+                    {}
+                  camera_rgb_optical_frame:
+                    {}
+                caster_back_link:
+                  {}
+                caster_front_link:
+                  {}
+                cliff_sensor_front_link:
+                  {}
+                cliff_sensor_left_link:
+                  {}
+                cliff_sensor_right_link:
+                  {}
+                gyro_link:
+                  {}
+                laser_mount_link:
+                  laser:
+                    {}
+                plate_bottom_link:
+                  {}
+                plate_middle_link:
+                  {}
+                plate_top_link:
+                  {}
+                pole_bottom_0_link:
+                  {}
+                pole_bottom_1_link:
+                  {}
+                pole_bottom_2_link:
+                  {}
+                pole_bottom_3_link:
+                  {}
+                pole_bottom_4_link:
+                  {}
+                pole_bottom_5_link:
+                  {}
+                pole_kinect_0_link:
+                  {}
+                pole_kinect_1_link:
+                  {}
+                pole_middle_0_link:
+                  {}
+                pole_middle_1_link:
+                  {}
+                pole_middle_2_link:
+                  {}
+                pole_middle_3_link:
+                  {}
+                pole_top_0_link:
+                  {}
+                pole_top_1_link:
+                  {}
+                pole_top_2_link:
+                  {}
+                pole_top_3_link:
+                  {}
+                wheel_left_link:
+                  {}
+                wheel_right_link:
+                  {}
+      Update Interval: 0
+      Value: true
+    - Class: Submaps
+      Enabled: true
+      Map frame: map
+      Name: Submaps
+      Submap query service: /cartographer/submap_query
+      Topic: /cartographer/submap_list
+      Tracking frame: base_link
+      Unreliable: false
+      Value: true
+    - Alpha: 1
+      Autocompute Intensity Bounds: true
+      Autocompute Value Bounds:
+        Max Value: 10
+        Min Value: -10
+        Value: true
+      Axis: Z
+      Channel Name: intensity
+      Class: rviz/PointCloud2
+      Color: 0; 255; 0
+      Color Transformer: FlatColor
+      Decay Time: 0
+      Enabled: true
+      Invert Rainbow: false
+      Max Color: 255; 255; 255
+      Max Intensity: 4096
+      Min Color: 0; 0; 0
+      Min Intensity: 0
+      Name: PointCloud2
+      Position Transformer: XYZ
+      Queue Size: 10
+      Selectable: true
+      Size (Pixels): 3
+      Size (m): 0.05
+      Style: Flat Squares
+      Topic: /scan_matched_points2
+      Unreliable: false
+      Use Fixed Frame: true
+      Use rainbow: true
+      Value: true
+  Enabled: true
+  Global Options:
+    Background Color: 100; 100; 100
+    Fixed Frame: map
+    Frame Rate: 30
+  Name: root
+  Tools:
+    - Class: rviz/Interact
+      Hide Inactive Objects: true
+    - Class: rviz/MoveCamera
+    - Class: rviz/Select
+    - Class: rviz/FocusCamera
+    - Class: rviz/Measure
+    - Class: rviz/SetInitialPose
+      Topic: /initialpose
+    - Class: rviz/SetGoal
+      Topic: /move_base_simple/goal
+    - Class: rviz/PublishPoint
+      Single click: true
+      Topic: /clicked_point
+  Value: true
+  Views:
+    Current:
+      Angle: 0
+      Class: rviz/TopDownOrtho
+      Enable Stereo Rendering:
+        Stereo Eye Separation: 0.06
+        Stereo Focal Distance: 1
+        Swap Stereo Eyes: false
+        Value: false
+      Name: Current View
+      Near Clip Distance: 0.01
+      Scale: 10
+      Target Frame: <Fixed Frame>
+      Value: TopDownOrtho (rviz)
+      X: 0
+      Y: 0
+    Saved: ~
+Window Geometry:
+  Displays:
+    collapsed: false
+  Height: 1123
+  Hide Left Dock: false
+  Hide Right Dock: false
+  QMainWindow State: 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
+  Selection:
+    collapsed: false
+  Time:
+    collapsed: false
+  Tool Properties:
+    collapsed: false
+  Views:
+    collapsed: false
+  Width: 1918
+  X: 0
+  Y: 24

cartographer_ros/launch/demo_turtlebot.launch

@@ -0,0 +1,29 @@
+<!--
+  Copyright 2016 The Cartographer Authors
+
+  Licensed under the Apache License, Version 2.0 (the "License");
+  you may not use this file except in compliance with the License.
+  You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+  Unless required by applicable law or agreed to in writing, software
+  distributed under the License is distributed on an "AS IS" BASIS,
+  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  See the License for the specific language governing permissions and
+  limitations under the License.
+-->
+
+<launch>
+  <param name="/use_sim_time" value="true" />
+
+  <node name="cartographer" pkg="cartographer_ros"
+      type="cartographer_node" args="
+          -configuration_directory $(find cartographer_ros)/configuration_files
+          -configuration_basename turtlebot.lua"
+      output="screen" />
+  <node name="rviz" pkg="rviz" type="rviz" required="true"
+      args="-d $(find cartographer_ros)/configuration_files/demo_turtlebot.rviz" />
+  <node name="playbag" pkg="rosbag" type="play"
+      args="--clock $(arg bag_filename)" />
+</launch>

cartographer_ros/src/cartographer_node_main.cc

@@ -43,6 +43,7 @@
 #include "cartographer/mapping_3d/local_trajectory_builder_options.h"
 #include "cartographer/mapping_3d/sparse_pose_graph.h"
 #include "cartographer/sensor/laser.h"
+#include "cartographer/sensor/point_cloud.h"
 #include "cartographer/sensor/proto/sensor.pb.h"
 #include "cartographer/transform/rigid_transform.h"
 #include "cartographer/transform/transform.h"
@@ -97,6 +98,7 @@ constexpr char kPointCloud2Topic[] = "/points2";
 constexpr char kImuTopic[] = "/imu";
 constexpr char kOdometryTopic[] = "/odom";
 constexpr char kOccupancyGridTopic[] = "/map";
+constexpr char kScanMatchedPointCloudTopic[] = "/scan_matched_points2";
 
 struct NodeOptions {
   carto::mapping::proto::MapBuilderOptions map_builder_options;
@@ -206,7 +208,8 @@ class Node {
       ::cartographer_ros_msgs::SubmapQuery::Response& response);
 
   void PublishSubmapList(const ::ros::WallTimerEvent& timer_event);
-  void PublishPose(const ::ros::WallTimerEvent& timer_event);
+  void PublishPoseAndScanMatchedPointCloud(
+      const ::ros::WallTimerEvent& timer_event);
   void SpinOccupancyGridThreadForever();
 
   const NodeOptions options_;
@@ -226,6 +229,7 @@ class Node {
   ::ros::Subscriber odometry_subscriber_;
   ::ros::Publisher submap_list_publisher_;
   ::ros::ServiceServer submap_query_server_;
+  ::ros::Publisher scan_matched_point_cloud_publisher_;
 
   tf2_ros::Buffer tf_buffer_;
   tf2_ros::TransformListener tf_;
@@ -426,12 +430,16 @@ void Node::Initialize() {
         std::thread(&Node::SpinOccupancyGridThreadForever, this);
   }
 
+  scan_matched_point_cloud_publisher_ =
+      node_handle_.advertise<sensor_msgs::PointCloud2>(
+          kScanMatchedPointCloudTopic, 10);
+
   wall_timers_.push_back(node_handle_.createWallTimer(
       ::ros::WallDuration(options_.submap_publish_period_sec),
       &Node::PublishSubmapList, this));
   wall_timers_.push_back(node_handle_.createWallTimer(
-      ::ros::WallDuration(options_.pose_publish_period_sec), &Node::PublishPose,
+      ::ros::WallDuration(options_.pose_publish_period_sec),
-      this));
+      &Node::PublishPoseAndScanMatchedPointCloud, this));
 }
 
 bool Node::HandleSubmapQuery(
@@ -508,21 +516,26 @@ void Node::PublishSubmapList(const ::ros::WallTimerEvent& timer_event) {
   submap_list_publisher_.publish(ros_submap_list);
 }
 
-void Node::PublishPose(const ::ros::WallTimerEvent& timer_event) {
+void Node::PublishPoseAndScanMatchedPointCloud(
+    const ::ros::WallTimerEvent& timer_event) {
   carto::common::MutexLocker lock(&mutex_);
-  const Rigid3d tracking_to_local =
+  const carto::mapping::GlobalTrajectoryBuilderInterface::PoseEstimate
-      map_builder_.GetTrajectoryBuilder(kTrajectoryBuilderId)
+      last_pose_estimate =
-          ->pose_estimate()
+          map_builder_.GetTrajectoryBuilder(kTrajectoryBuilderId)
-          .pose;
+              ->pose_estimate();
+  if (carto::common::ToUniversal(last_pose_estimate.time) < 0) {
+    return;
+  }
+
+  const Rigid3d tracking_to_local = last_pose_estimate.pose;
   const carto::mapping::Submaps* submaps =
       map_builder_.GetTrajectoryBuilder(kTrajectoryBuilderId)->submaps();
   const Rigid3d local_to_map =
       map_builder_.sparse_pose_graph()->GetLocalToGlobalTransform(*submaps);
   const Rigid3d tracking_to_map = local_to_map * tracking_to_local;
 
-  const ::ros::Time now = ::ros::Time::now();
   geometry_msgs::TransformStamped stamped_transform;
-  stamped_transform.header.stamp = now;
+  stamped_transform.header.stamp = ToRos(last_pose_estimate.time);
   stamped_transform.header.frame_id = options_.map_frame;
   stamped_transform.child_frame_id = options_.odom_frame;
 
@@ -537,7 +550,8 @@ void Node::PublishPose(const ::ros::WallTimerEvent& timer_event) {
   } else {
     try {
       const Rigid3d tracking_to_odom =
-          LookupToTrackingTransformOrThrow(FromRos(now), options_.odom_frame)
+          LookupToTrackingTransformOrThrow(last_pose_estimate.time,
+                                           options_.odom_frame)
               .inverse();
       const Rigid3d odom_to_map = tracking_to_map * tracking_to_odom.inverse();
       stamped_transform.transform = ToGeometryMsgTransform(odom_to_map);
@@ -547,6 +561,12 @@ void Node::PublishPose(const ::ros::WallTimerEvent& timer_event) {
                    << options_.odom_frame << ": " << ex.what();
     }
   }
+
+  scan_matched_point_cloud_publisher_.publish(ToPointCloud2Message(
+      carto::common::ToUniversal(last_pose_estimate.time), options_.tracking_frame,
+      carto::sensor::TransformPointCloud(
+          last_pose_estimate.point_cloud,
+          tracking_to_local.inverse().cast<float>())));
 }
 
 void Node::SpinOccupancyGridThreadForever() {

cartographer_ros/src/msg_conversion.cc

@@ -37,6 +37,7 @@
 #include "time_conversion.h"
 
 namespace cartographer_ros {
+
 namespace {
 
 // The ros::sensor_msgs::PointCloud2 binary data contains 4 floats for each
@@ -62,6 +63,35 @@ void ToMessage(const ::cartographer::transform::proto::Quaterniond& proto,
   quaternion->z = proto.z();
 }
 
+sensor_msgs::PointCloud2 PreparePointCloud2Message(const int64 timestamp,
+                                                   const string& frame_id,
+                                                   const int num_points) {
+  sensor_msgs::PointCloud2 msg;
+  msg.header.stamp = ToRos(::cartographer::common::FromUniversal(timestamp));
+  msg.header.frame_id = frame_id;
+  msg.height = 1;
+  msg.width = num_points;
+  msg.fields.resize(3);
+  msg.fields[0].name = "x";
+  msg.fields[0].offset = 0;
+  msg.fields[0].datatype = 7;
+  msg.fields[0].count = 1;
+  msg.fields[1].name = "y";
+  msg.fields[1].offset = 4;
+  msg.fields[1].datatype = 7;
+  msg.fields[1].count = 1;
+  msg.fields[2].name = "z";
+  msg.fields[2].offset = 8;
+  msg.fields[2].datatype = 7;
+  msg.fields[2].count = 1;
+  msg.is_bigendian = false;
+  msg.point_step = 16;
+  msg.row_step = 16 * msg.width;
+  msg.is_dense = true;
+  msg.data.resize(16 * num_points);
+  return msg;
+}
+
 }  // namespace
 
 sensor_msgs::MultiEchoLaserScan ToMultiEchoLaserScanMessage(
@@ -149,42 +179,32 @@ sensor_msgs::LaserScan ToLaserScan(
   return msg;
 }
 
+sensor_msgs::PointCloud2 ToPointCloud2Message(
+    const int64 timestamp, const string& frame_id,
+    const ::cartographer::sensor::PointCloud& point_cloud) {
+  auto msg = PreparePointCloud2Message(timestamp, frame_id, point_cloud.size());
+  ::ros::serialization::OStream stream(msg.data.data(), msg.data.size());
+  for (const auto& point : point_cloud) {
+    stream.next(point.x());
+    stream.next(point.y());
+    stream.next(point.z());
+    stream.next(kPointCloudComponentFourMagic);
+  }
+  return msg;
+}
+
 sensor_msgs::PointCloud2 ToPointCloud2Message(
     const int64 timestamp, const string& frame_id,
     const ::cartographer::sensor::proto::LaserFan3D& laser_scan_3d) {
   CHECK(::cartographer::transform::ToEigen(laser_scan_3d.origin()).norm() == 0)
       << "Trying to convert a laser_scan_3d that is not at the origin.";
 
-  sensor_msgs::PointCloud2 msg;
-  msg.header.stamp = ToRos(::cartographer::common::FromUniversal(timestamp));
-  msg.header.frame_id = frame_id;
-
   const auto& point_cloud = laser_scan_3d.point_cloud();
   CHECK_EQ(point_cloud.x_size(), point_cloud.y_size());
   CHECK_EQ(point_cloud.x_size(), point_cloud.z_size());
   const auto num_points = point_cloud.x_size();
 
-  msg.height = 1;
+  auto msg = PreparePointCloud2Message(timestamp, frame_id, num_points);
-  msg.width = num_points;
-  msg.fields.resize(3);
-  msg.fields[0].name = "x";
-  msg.fields[0].offset = 0;
-  msg.fields[0].datatype = 7;
-  msg.fields[0].count = 1;
-  msg.fields[1].name = "y";
-  msg.fields[1].offset = 4;
-  msg.fields[1].datatype = 7;
-  msg.fields[1].count = 1;
-  msg.fields[2].name = "z";
-  msg.fields[2].offset = 8;
-  msg.fields[2].datatype = 7;
-  msg.fields[2].count = 1;
-  msg.is_bigendian = false;
-  msg.point_step = 16;
-  msg.row_step = 16 * msg.width;
-  msg.is_dense = true;
-  msg.data.resize(16 * num_points);
-
   ::ros::serialization::OStream stream(msg.data.data(), msg.data.size());
   for (int i = 0; i < num_points; ++i) {
     stream.next(point_cloud.x(i));

cartographer_ros/src/msg_conversion.h

@@ -19,6 +19,7 @@
 
 #include "cartographer/common/port.h"
 #include "cartographer/kalman_filter/pose_tracker.h"
+#include "cartographer/sensor/point_cloud.h"
 #include "cartographer/sensor/proto/sensor.pb.h"
 #include "cartographer/transform/rigid_transform.h"
 #include "geometry_msgs/Pose.h"
@@ -34,7 +35,7 @@
 
 namespace cartographer_ros {
 
-// Only uses first echo of each beam.
+// Returns a laser scan consisting of the first echo of each beam.
 sensor_msgs::LaserScan ToLaserScan(
     int64 timestamp, const string& frame_id,
     const ::cartographer::sensor::proto::LaserScan& laser_scan);
@@ -46,6 +47,10 @@ sensor_msgs::MultiEchoLaserScan ToMultiEchoLaserScanMessage(
 sensor_msgs::Imu ToImuMessage(int64 timestamp, const string& frame_id,
                               const ::cartographer::sensor::proto::Imu& imu);
 
+sensor_msgs::PointCloud2 ToPointCloud2Message(
+    int64 timestamp, const string& frame_id,
+    const ::cartographer::sensor::PointCloud& point_cloud);
+
 sensor_msgs::PointCloud2 ToPointCloud2Message(
     int64 timestamp, const string& frame_id,
     const ::cartographer::sensor::proto::LaserFan3D& laser_scan_3d);