Retrieve the coordinates of the occluding (closest/drawn) pixels during 3D overlap, using OpenGL?

Posted by Big Rich on Game Development See other posts from Game Development or by Big Rich
Published on 2011-01-16T05:35:02Z Indexed on 2011/01/16 6:01 UTC
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3d

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opengl

Hi, Sorry if the question is not worded well, I'm a new to both 3D and OpenGL.

How could I go about obtaining the 3D coordinates of the occluding object, at the point where occlusion is happening (i.e. the 'intersection' of the object in front/closest to the screen)?

Just to offer a [very] rudimentary, visual, example, if you were to form an index-finger cross, with your right hand closest to your face, I'd like to know the coordinates of the part of your right finger which obscures the other finger (obviously back within the OpenGL context - no jokers ;-) ).

If there is a way to find out both about the occluder (hider) and the occluded (hidden) objects in OpenGL, then that would be of great use, also.

Cheers

Rich

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