Celestia Forums

hello there,

after a while of absence i got back to compiling me a latest svn release yesterday (r4651).
since the last time my computer specs have changed a bit and i upgraded all my old nvidia cards with ati cards.

build was fine and celestia runs fine but when I enable antialiassamples in config or through CCC i see this:


as you can see the once beautiful asteroid-belt has turned into a weird blob of grey and my usually 60 FPS (synced to tft) turn into a slideshow.
i tried x2, x4 and x8 which only gets worse.
the problem only persists with opengl 2.0 render path and only with that asteroid belt.
as soon as i leave it's sight everything is back to normal again.

after tweaking every possible 3d-setting in CCC enabling "catalyst A.I." to "advanced" will crash celestia upon start without an error, it just drops back to windows and does nothing.

tested both on windows xp pro 32 bit with an HD3870 and HD4670 with same results on two different intel machines.
here's the opengl info for the 3870 if it helps.

This is a problem with the ATI OpenGL driver's and support for point sprites, which are used in the asteroid belt add-on. Quite simply, the newer ATI drivers seem to have completely broken point sprite support on all platforms. The sizing of the sprites is completely wrong: instead of tiny points, the sprites are huge blobs. Drawing tens of thousands of these blobs is slowing down rendering to a crawl.

Does the problem go away when antialiasing is disabled?

--Chris

yes, no AA = no problem

phoenix wrote:yes, no AA = no problem

Interesting! This information might lead to a workaround for the ATI point sprites problem. Can you post a screenshot with AA disabled?

--Chris

phoenix wrote:yes, no AA = no problem

FSAA is enabled on my ATI machine. I never switched it OFF to test my sprites models before. I may try some test this weekend to see if there's any differences...

with no AA it looks just normal: