multi-level collision detection

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Hello, CAn Anyone Help ...


Problem:
I´am working in a multi-level collision detection using a depth map.
The process is simple, In a top view, I down the Z-Near to Z-Far, and save the image depth in a matrix. Then I compare the Depth´s in images to finder a path without a collision. But Opengl not keep a perpendicular line in the image.....


So, there is the question:
In a top view, when down the Z-Near the vertical walls of a building disappear of the top image, so that, I can´t identify this collision.
I have used glPolygonMode(GL_BACK,GL_LINE) to keep at the end the the line that corresponds at a wall, but when use glEnable(GL_DEPHT_TEST) the problem persists.

Any idea? to solve this?

:wacko:

Thanks all

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