HOWTO : EXT_vertex_blend

[pav]

hi, i kinda got confused with the hardware vertex blending using this extension..in a word...i can't do it..
i don't understand what the 4 matrices are for...
i didn't use any matrices in the software blending.

can any of you guide me how to blend the vertices in hardware?
(I have a Radeon card which supports it)
thanx...

 

[Humus]

Not that I'm particularily good at this myself, havenät used this extension, but if you've used any professional tool like maya for skinning the pieces will fall in place more easily, it's quite easy to understand when you look how things are done in those apps.

Basically, you make a model giving it a transform (a matrix) for each of it's bones and use vertices relative to the bone. Then you interpolate the vertices as if they would have been rotated by mat1 or by mat2, taking for instance 0.5 * mat1_result + 0.5 * mat2_result.

Hmm, I'm no good at explaining this ...
Anyway, ATi has an sample app using this extension, haven't checked it out too deeply myself though.