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MButchers
05-19-2001, 01:21 AM
Hello there,

would it be possible to enable changes to the current matrix between these calls to
glBegin(..) glEnd() as this would be
extremely usefull in rendering particle fx
and skeletal animations.

Siigron
05-19-2001, 03:26 AM
glBegin and glEnd are old and deprecated.
use vertex arrays instead.

ET3D
05-19-2001, 07:11 AM
I don't think that they are deprecated. Are they? And in any case, I'm not sure that this answers MButchers. If I understand correctly, what he wants to do is transform one vertex using one matrix, and another using another matrix. Using vertex arrays is not an answer to this.

MButchers, if I understand correctly what you want, then there are a couple of extensions that provide several modelview matrices, and blend the results of vector transformation using them. They could be used to specify different matrices for different vertices, but using 1 for the blend factor of the specific matrix, and 0 for the others, or you can blend the results, which would perhaps be even better for things like skeletal animations.

Unfortunately, it seems that NVIDIA (TNT, GeForce chip families) and ATI (Radeon) use different extensions. ATI uses ARB_vertex_blend(http://oss.sgi.com/projects/ogl-sample/registry/ARB/vertex_blend.txt), which supports up to 32 matrices, while NVIDIA seems to implement only EXT_vertex_weighting
(http://oss.sgi.com/projects/ogl-sample/registry/EXT/vertex_weighting.txt), which supports only two modelview matrices.

MButchers
05-19-2001, 08:21 AM
Thanks ET3D i will take a look at these.