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dabeav
12-13-2002, 10:05 AM
Im working on a cell shading renderer, and i was curious, What is the performance difference (if any) between multitexturing a 1D and 2D texture togeather OR calling a color call per vertex along with a 2D texture? Is the color modulated to the texture in one pass or two?

Coriolis
12-13-2002, 10:42 AM
My guess is they'd be the same. But try and see! That's always the best way to be sure.

EDIT: but if you do a 1D texture you will get perspective-correct interpolation, while if you use vertex colors it will probably be affine interpolation.

[This message has been edited by Coriolis (edited 12-13-2002).]

mcraighead
12-13-2002, 12:31 PM
All NVIDIA hardware released in the last 4 years has perspective-correct color interpolation.

- Matt

Coriolis
12-13-2002, 04:00 PM
Matt -

I had some annoying artifacts in color interpolation on my GeForce4 when triangles got clipped to the frustum until I set GL_PERSPECTIVE_CORRECTION_HINT to GL_NICEST. So I surmised that the video card / driver defaults to affine interpolation, though I guess this could have been a different issue.

mcraighead
12-13-2002, 09:42 PM
I have a hard time believing that story... we quite thoroughly ignore the perspective correction hint on all hardware, and have ignored it as along as I can remember. I suspect you got a placebo effect.

- Matt

Zeno
12-13-2002, 11:15 PM
Maybe the problem only appears in rotating reference frames?

Har har. Sorry, I couldn't resist http://www.opengl.org/discussion_boards/ubb/wink.gif

-- Zeno

[This message has been edited by Zeno (edited 12-14-2002).]