Hi,
One reason why I couldn’t get mipmapping to work properly was duie to the fast that I was trying to use GL_TEXTURE_BASE_LEVEL and GL_TEXTURE_MAX_LEVEL in glTexParameter*().
I know that these are 1.2 features and not 1.1, but as I thought the NVidia driver I have would take it, it seemed like it might work. When I used these two parameters, it kills the speed of the rendering to somewhere between 0-10 FPS.
This is very strange. Is there a way of using these features? What about other drivers (for other cards)?
I am currently using the new Detonator 3 drivers from NVidia.
Thanks to the people who tried to help me with this problem.
Thanks,
Luke A. Guest.
On TNT/TNT2, those particular features are implemented in SW with currently-released drivers. All GeForce-class cards do them in HW. (The MIN_LOD and MAX_LOD floating-point clamp are also the same way – SW on TNT2, HW on GeForce.)
Our next driver release will add support for MAX_LEVEL in HW on TNT2, but no BASE_LEVEL, MIN_LOD, or MAX_LOD. It would be nice to do BASE_LEVEL, but we can’t do it in the totally general case, only in certain specific cases, on that particular HW, and then the set of rules you’d have to learn for when it would work would get confusing.
Originally posted by mcraighead:
[b]On TNT/TNT2, those particular features are implemented in SW with currently-released drivers. All GeForce-class cards do them in HW. (The MIN_LOD and MAX_LOD floating-point clamp are also the same way – SW on TNT2, HW on GeForce.)
Our next driver release will add support for MAX_LEVEL in HW on TNT2, but no BASE_LEVEL, MIN_LOD, or MAX_LOD. It would be nice to do BASE_LEVEL, but we can’t do it in the totally general case, only in certain specific cases, on that particular HW, and then the set of rules you’d have to learn for when it would work would get confusing.
I thought the BASE_LEVEL and MAX_LEVEL parameters just defined the number of mimaps you wan to use for your texture? Surely, this shouldn’t slow the machine down to a crawl? Surely?
Thanks,
Luke.
It shouldn’t, but we don’t have a good way of selecting which mipmaps to use on that particular HW, and so we have no choice but to fall back to SW.
Originally posted by mcraighead:
[b]It shouldn’t, but we don’t have a good way of selecting which mipmaps to use on that particular HW, and so we have no choice but to fall back to SW.
Hmmm, strange. Would it be possible to say, I want 3 levels and just set those to switch at particular distances defined by the driver?
Luke.
No, we have nowhere near that much control.