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