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37 lines
1.3 KiB
37 lines
1.3 KiB
3 years ago
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function inside = PointInsideVolume(point, faces, vertices)
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%% Point within the volume test
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% TriangleRayIntersection is a low level function which can be used to
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% solve higher level problems. For example a test to see if point is inside
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% or outside of a volume defined by a continous surface:
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%% chack input
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if nargin==2 && isa(faces, 'triangulation')
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[faces, vertices] = freeBoundary(faces);
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end
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switch size(point,2)
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case 2 % 2D case
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xv = vertices(faces', 1); % define polygon
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yv = vertices(faces', 2);
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inside = inpolygon(point(:,1), point(:,2), xv, yv);
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case 3
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eps = 1e-5;
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vert1 = vertices(faces(:,1),:);
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vert2 = vertices(faces(:,2),:);
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vert3 = vertices(faces(:,3),:);
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inside = false(size(point,1),1);
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for iPoint = 1:size(point,1)
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certain = 0;
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while ~certain
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dir = rand(1,3)-0.5; % pick random direction
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[intersect, ~, u, v] = TriangleRayIntersection(point(iPoint,:), ...
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dir, vert1, vert2, vert3, 'border', 'inclusive');
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nIntersect = sum(intersect); % number of intersections
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inside(iPoint) = mod(nIntersect,2)>0; % inside if odd number of intersections
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% make sure ray stays away fron surface triangle edges
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bary = [u, v, 1-u-v];
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bary = bary(intersect,:);
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certain = all( min(abs(bary),[], 2)>eps );
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end
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end
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end
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