asshen at November 10th, 2003 15:41 — #1
How do I extract the 8 vertices of a frustum ?
I can calculate the 6 planes, and I have the result in frustum...
But how do I now extract the 8 frustum verts from that ???
Is there any opengl extension that extracts the frustum ?
davepermen at November 10th, 2003 20:34 — #2
gluUnproject (or similar) could help.. just throw in the 8 signed-unit-cube coords..
then again, thats just a blind guess..
you could as well search for a point intersection_of(plane a,plane b,plane c) code, and just intersect all combinations of planes for the points..
asshen at November 11th, 2003 11:15 — #3
gluUnproject is too slow for getting the frustum.
I'm currently using the frustum plane extraction code by Mark Morley.
But this only gives me 6 planes.
But I also need the 8 verts for my project
I heard that there is an opengl extension for extracting the frustum?
Maybe that one could help me ?
Anyway, if you could direct me to a 3x plane intersection code example, that would get me on my way
anubis at November 11th, 2003 12:55 — #4
always a good starting point if you have mathprobs
never heard of such an extension... http://oss.sgi.com/projects/ogl-sample/registry/
davepermen at November 11th, 2003 14:28 — #5
gluUnproject is not slow to get called 8 times. not that its the most efficient way. but something that gets called 8 times per frame never hurts.. i call very expensive functions 100000 times per frame and have smooth fps..
get it working.
get it save working.
get it fast working.
first: get it WORKING
anubis at November 11th, 2003 14:51 — #6
something is wrong with the posting screen, anway...
hehe, just the coding paradigm we talked about
davepermen at November 11th, 2003 15:49 — #7
whats wrong with it? i don't see anything..
yes. always the same:D