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Krippy2k

Having issues with frustrum culling

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Hi all Well I now have my complex level data partitioned into an octree and everything is working fine with the operation of the octree as a data structure and it works when using it to do collision detection but my old method I was able to work out enough that it is actually faster than the octree for this. But now I am stuck on trying to figure out how to determine if a node (an axis-aligned cube) is completely outside of the viewing frustrum or not. Yes I have searched google and have not come up with anything that is useful to me. I get lots of links to pages telling what view frustrum culling is, and pre-built engines that use it but nothing about the actual math or algorithm involved. I''m sure that there is something out there to be found and I will find it eventually but I am hoping somebody can help point me in the right direction here Thanks alot, Krippy

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Check this link:

http://www.cubic.org/~submissive/sourcerer/3dclip.htm

I guess that will help you out!

Also another tip:
Cull in ObjectSapce! You don''t want to transform the whole 8-tree thingie and compare it to the frustem.
Do a inverse-transform on your frustum and cull the octree using that frustum.

There''s a tutorial on 3D Culling in Objspace also on the link:
http://www.cubic.org/~submissive/sourcerer/

Gr,
BoRReL

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Hey thanks alot man!

That is exactly what I needed. Now I am culling my octree at blazing speeds lol

Actually I am now averaging 70fps (my refresh rate) at 1600x1200x16 compared to 35 before implementing the octree. And I know I can still optimize things a considerable amount more now because my implementation is brute force at the moment. And my math functions are all using the standard C library math functions operating on doubles.

Thanks again

Seeya
Krippy

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