[osg-users] Point Selection in Point Cloud

[Filip Arlet]

Hi,

It really depends on how big your point cloud is. General rule is to create tree (kd-tree, octree, ...). Either multiple nodes or on big custom drawable with tree in it. If you create custom drawable, you can test if ray intersects tree node or polytope contains tree node. If you create tree with osg::Nodes(Groups), osgUtil::Polytope intersector will do the job for you. But you would need to aguament it to contain all your intersections (if you would have many intersection I recommend three sets -> 1) nodes completely in polytope, 2) nodes partially in polytope 3) nodes completely outside polytope. 

2D window rectangle polytope can be created in window coordinates:
osgUtil::PolytopeIntersector (osgUtil::PolytopeIntersector::WINDOW, xMin, yMin, xMax, yMax)
Cheers,
Filip

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