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View Full Version : Mipmapping on ATI Rage Pro?



Bert
09-27-2000, 12:41 PM
I have set up mipmapping for a brick wall and on my iMac DV SE with a ATI Rage 128 it works fine. But on an iMac 333 with an ATI Rage Pro I believe, there does not seem to be any mipmapping at all. I get the moire pattern or whatever they are called. Is this a card specific thing or is there a way to enable mipmaping on the older machines?

Morgan
09-28-2000, 09:01 AM
Ha! That's funny, when I switched from my iMac (Rev B) w/Rage Pro to my PowerBook (Pismo) w/Rage 128 Mobility I didn't like the fact that my mipmapped textures were so blurry when really far away. I don't think the 333Mhz iMacs had Rage Pro's, but I could be mistaken, you shouls use the Apple System Profiler app to check on that, but there is mipmap support, it's just not as great.

Morgan

Bert
09-28-2000, 06:05 PM
I thought that was the right card but I may be mistaken. What constitutes "not as great support" for mipmapping?

Some of the textures look better without and some with mipmapping. I think it is best to decide texture by texture. Though textures with skinnylines, like bricks or skinny lettering styles, tend to look better with mipmapping. The high frequency stuff makes bad patterns all on the texture. While textures with fatter details tend to look better without mipmapping. There are no high frequency patterns to be created from wrong frequency sampling.

tdavie
09-28-2000, 11:54 PM
I have an iMac 333 too, I am pretty sure that it is an ATi RAGE pro in it (the only differance in graphics hardware from the previous version is that it has 6 Mb instead of 4 Mb).
I have also had the same problems with mipmapping, although the times I have had the problems is only with greyscale textures. These when viewed at a distance (or mapped onto a small object) get interfearance patterns all over them. However simmilarly sized colour textures do not.

Morgan
09-29-2000, 06:35 AM
Hmm, mine is an iMac (Rev B), 266Mhz, RAGE Pro (w/6MB VRAM), it was the first with the RAGE Pro (w/6MB VRAM instead or 4MB VRAM), I thought they changed it a couple models laterf, but I guess not.

Morgan

Bert
09-29-2000, 07:48 AM
Hmmm. My problem is with color textures. I made a Miniature Golf game and the bricks, mostly red, brown, gray, and white in color, has patterns when far away and I use either trilinear filtering or nearest mipmapping. The results seem the same if I do not use mipmapping at all. I do not know if this is a card thing or a software rendering thing or what.

tdavie
09-30-2000, 03:23 AM
I can understand this happening with nearest mipmapping but with linear mipmapping it should use a bicubic algorithm to calculate the texel colours so you should get a blury immage instead of one with interfearance patters.
Have you tried not using mip mapping but usinging realtime linear rendering (just to see what happens)?