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python_regious

Geomipmapping...

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Ok, I''m about to implement geomipmapping into my engine, and there is one thing that I don''t know. How would I find the "Top coordinate of the near-clipping plane"? Finding the near clipping plane I can do, but surely that depends on the modelview matrix aswell, and this is supposed to be precalculated... Hmm... Death of one is a tragedy, death of a million is just a statistic.

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Somewhere in your app you either make a call to gluPerspective or glfrustrum. the top-coordinate is one of the params to the glFrustrum call. If you use gluPerspective you can calculate it this way (this is from the mesa source btw) :

t = zNear * tan(fovy * PI/360.0f);

zNear and fovy are the params you pass to gluPerspective.

(I'm assuming you're using opengl, direct3d probably has something similar)

[edited by - George2 on September 2, 2002 2:24:50 PM]

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