texture vs. register combiners


What are the advantages or disadvantages of using NV_register_combiners over ARB_texture_env_combine? What are the situations where one would decide to use one over the other? Is it that register combiners allow you to do the combining before it is bound to a texture unit? I’m confused about which to use. Thanks.

  • Q.

Register combiners allow you to do more operations per pixel as well as do basic if statements (using the mux).

[This message has been edited by jra101 (edited 07-22-2003).]

And of course, NV_xyz only works on NVIDIA hardware. Otherwise I think it’s more general than texture environments (though in most cases you can do the same thing with both).

I think stuff like bumpmapping is not possible with texture combiners.
Well, at least i never tried it (and i am quite sure the reason was, that it´s not possible).

However, if you understand the one, than you also will understand the other extension. And then you will know, what is possible with each one.


Env_combine and dot3 extension allows bumpmapping with just opengl1.4 or any open with those extensions.

Incase there’s any lingering doubt here is a detailed tutorial on doing this:

Originally posted by Jan2000:
I think stuff like bumpmapping is not possible with texture combiners…

Uh-oh, I always though reg combs were designed to do bumpmapping.

Aren’t OpenGL “combiners” equivalent to DirectX texture stage operations?

It gives you greater control how textures are blended at each texture unit?

It is possible, there is code, it has been posted, move along there’s nothing to see.