90 lines
		
	
	
		
			3.0 KiB
		
	
	
	
		
			Matlab
		
	
	
			
		
		
	
	
			90 lines
		
	
	
		
			3.0 KiB
		
	
	
	
		
			Matlab
		
	
	
| function [visiblePoints] = cylinderSampleProjection(K, pose, imageSize, cylinders)
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| 
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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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| 
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| import gtsam.*
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| 
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| camera = PinholeCameraCal3_S2(pose, K);
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| 
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| %% memory allocation
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| cylinderNum = length(cylinders);
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| 
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| %% check visiblity of points on each cylinder
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| pointCloudIndex = 0;
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| visiblePointIdx = 1;
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| for i = 1:cylinderNum
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|     
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|     pointNum = length(cylinders{i}.Points);
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| 
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|     % to check point visibility        
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|     for j = 1:pointNum
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| 
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|         pointCloudIndex  = pointCloudIndex + 1;
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|                 
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|         % Cheirality Exception
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|         sampledPoint3 = cylinders{i}.Points{j};
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|         sampledPoint3local = pose.transformTo(sampledPoint3);        
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|         if sampledPoint3local.z <= 0
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|             continue; 
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|         end
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|         Z2d = camera.project(sampledPoint3);
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| 
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|         % ignore points not visible in the scene
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|         if Z2d.x < 0 || Z2d.x >= imageSize.x || Z2d.y < 0 || Z2d.y >= imageSize.y 
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|             continue;       
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|         end            
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| 
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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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|         visible = true;
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|         for k = 1:cylinderNum
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| 
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|             rayCameraToPoint = pose.translation().between(sampledPoint3).vector();
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|             rayCameraToCylinder = pose.translation().between(cylinders{k}.centroid).vector();
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|             rayCylinderToPoint = cylinders{k}.centroid.between(sampledPoint3).vector();
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| 
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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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|                continue;
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|             else 
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|                 projectedRay = dot(rayCameraToCylinder, rayCameraToPoint) / norm(rayCameraToCylinder);
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|                 if projectedRay > 0
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|                     %rayCylinderToProjected = rayCameraToCylinder - norm(projectedRay) / norm(rayCameraToPoint) * rayCameraToPoint;
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|                     if rayCylinderToPoint(1) > cylinders{k}.radius && ...
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|                             rayCylinderToPoint(2) > cylinders{k}.radius
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|                        continue;
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|                     else
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|                         visible = false;
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|                         break;
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|                     end
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|                 end
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|             end
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|             
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|         end
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|         
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|         if visible
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|             visiblePoints.data{visiblePointIdx} = sampledPoint3;
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|             visiblePoints.Z{visiblePointIdx} = Z2d;
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|             visiblePoints.cylinderIdx{visiblePointIdx} = i;
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|             visiblePoints.overallIdx{visiblePointIdx} = pointCloudIndex;
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|             visiblePointIdx = visiblePointIdx + 1;
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|         end
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| 
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|     end
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|     
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| end
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|     
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| end
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