Hi everybody,
I’m a little confused right now. I’ve been working on switching my system to using glVertexAttrib* (either immediate mode in DLists or VBOs). I’m currently just running the fixed function pipeline, not a shader.
On nVidia that works fine, but on ATI it seems like only the position is used, the other arguments are just ignored. I’ve just gone through the GL_ARB_vertex_program spec, and I’m not sure I really understand how that applies to my case.
I know that there issues to be expected when mixing classical and generic attributes, but I’m not doing that, everything is generic. In that case I would expect everything to alias nicely into the classical attributes and therefore just work for the fixed function pipeline. If that is not the case, why does it work for the position but for nothing else? Or is that covered by saying the aliasing behaviour is just undefined?
Can anybody enlighten me? Am I barking at a bug in ATI’s driver (1.3.5140 (X4.3.0-8.14.13) on Fedora Core 4)? Is there any way to enable/control this behaviour?
Because I’m putting this stuff into display lists that can be shared between objects with different materials, switching between classic and attribute rendering will be very difficult to do. Not to talk about completely killing the nice separation of state and geometry I have right now, and that I would really like to keep.
Thanks
Dirk