gtsam/matlab/+gtsam/cylinderSampleProjection.m

90 lines
3.0 KiB
Matlab

function [visiblePoints] = cylinderSampleProjection(K, pose, imageSize, cylinders)
% Input:
% Output:
% visiblePoints: data{k} 3D Point in overal point clouds with index k
% Z{k} 2D measurements in overal point clouds with index k
% index {i}{j}
% i: the cylinder index;
% j: the point index on the cylinder;
%
% @Description: Project sampled points on cylinder to camera frame
% @Authors: Zhaoyang Lv
import gtsam.*
camera = PinholeCameraCal3_S2(pose, K);
%% memory allocation
cylinderNum = length(cylinders);
%% check visiblity of points on each cylinder
pointCloudIndex = 0;
visiblePointIdx = 1;
for i = 1:cylinderNum
pointNum = length(cylinders{i}.Points);
% to check point visibility
for j = 1:pointNum
pointCloudIndex = pointCloudIndex + 1;
% Cheirality Exception
sampledPoint3 = cylinders{i}.Points{j};
sampledPoint3local = pose.transformTo(sampledPoint3);
if sampledPoint3local.z <= 0
continue;
end
Z2d = camera.project(sampledPoint3);
% ignore points not visible in the scene
if Z2d.x < 0 || Z2d.x >= imageSize.x || Z2d.y < 0 || Z2d.y >= imageSize.y
continue;
end
% ignore points occluded
% use a simple math hack to check occlusion:
% 1. All points in front of cylinders' surfaces are visible
% 2. For points behind the cylinders' surfaces, the cylinder
visible = true;
for k = 1:cylinderNum
rayCameraToPoint = pose.translation().between(sampledPoint3).vector();
rayCameraToCylinder = pose.translation().between(cylinders{k}.centroid).vector();
rayCylinderToPoint = cylinders{k}.centroid.between(sampledPoint3).vector();
% Condition 1: all points in front of the cylinders'
% surfaces are visible
if dot(rayCylinderToPoint, rayCameraToCylinder) < 0
continue;
else
projectedRay = dot(rayCameraToCylinder, rayCameraToPoint) / norm(rayCameraToCylinder);
if projectedRay > 0
%rayCylinderToProjected = rayCameraToCylinder - norm(projectedRay) / norm(rayCameraToPoint) * rayCameraToPoint;
if rayCylinderToPoint(1) > cylinders{k}.radius && ...
rayCylinderToPoint(2) > cylinders{k}.radius
continue;
else
visible = false;
break;
end
end
end
end
if visible
visiblePoints.data{visiblePointIdx} = sampledPoint3;
visiblePoints.Z{visiblePointIdx} = Z2d;
visiblePoints.cylinderIdx{visiblePointIdx} = i;
visiblePoints.overallIdx{visiblePointIdx} = pointCloudIndex;
visiblePointIdx = visiblePointIdx + 1;
end
end
end
end