Hello everybody. I''m currently working on a little 3D game. The engine is advanced enough to fly around over an island, like seen on the screen shots there : http://artillerie.vdc4.org The island is displayed using a LOD method. My big problem is that it doesn''t seem to work on ATI brand cards. I was reported the island simply doesn''t appear !! On NVidia it works pretty good. Also the framerate is a problem, because on a Geforce FX 5900 XT I reach 160 FPS, and on a ATI 9800 it runs at 2.5 FPS !! Anyone has ever seen something like that?? Any hint where there ca be a bug?? I''m really getting nuts with this stuff. Any help will be greatly appreciated. A little demo of the program can be downloadaed there http://artillerie.vdc4.org/Artillerie.zip

ATI cards are mroe sensitive to various parametrs in the calls. I ran into a similar issue with DrawIndexedPrimitive. Check its values are all correct. NVidia cards do not care but for ATI cards all valeus must be correct.

If your all values are corerct, then it will run on both the cards

AQ : Ok, thanks for the tip. I''ll check the DrawIndexedPrimitive call again. Anybody who has a working example of it using triangle_fans?

Hedos : thanks for the report :-)

her is the discussion thread for the problem that i reported. Jsut make sure you clearly understand all the prameters of DrawIndexedPrimitive(). It was a big problem for me!

http://www.gamedev.net/community/forums/topic.asp?topic_id=225176

AQ : thanks a lot, i juste spotted this thraed 5 minutes ago :-p

It''s weird because before making my own thread I tried to search the forum for this. Anyway I now understand what was wrong. Thanks a lot indeed.