   a part of my Mesh is Dark !!!!
  hi guys , down u can find a link to a screen Shot taken on 2 different Computers and the lighting differs between them on different VGA cards i am using fixed function pipeline lighting not Shaders . is the Nvidia VGA Card better than Radeon VGA Card knowing that the radeon is 256MB while the Nvidia is 128MB !!! Did anyone face this problem before ?? and what could be the problem ? thanx for help.PS : the stage is only one .X file with the lighted and not lighted parthttp://tinypic.com/icjkhg.jpg   
  Could you please rephase?   ;  The first 2 possibilities that occur to me:1) Driver bug. They're very rare though, so if you assume it's your fault you're usually right.  Try running it using the Reference Rasterizer on both cards and see what the result is.2) You're not setting/resetting your states properly.  Maybe 1 driver is setting a different default than the other. At any rate, if you need a render/texture state set a certain way, set it explicitly.;  i  installed the VGA driver again but the same problem , and also tried to create my driver in different ways but also the same problem , but i noticed something on the computer that the graphic is shown  that is if i define a light in with direction (0,0,0) , the scene will be lighted and the ground will appeare but if i changed the direction of the light the scene will be dark as on the other computer which contain the radeon VGA Card so without this lightdirection(0,0,0) the scene will be half black like the picture above . but this is not working on the radeon VGA computer with or without this light direction it will stay dark . so any advices ????   ;  either the texture wasn't loaded at all or there is something diffrent about the way the GFX card responded i would recomend to switch to REF and see if its still black.   ;  Nvidia's drivers tend to be more forgiving of programmer error than ATI drivers. So if something works on Nvidia and doesn't work on ATI, suspect your own code.Check the debug spew... is it telling you anything that sounds troubling?   ;  i used reference Device but still the same problem  and the debug contains no suspicious errors . the normals of the ground mesh are computed correctly and everything seems to be correct but i noticed something when i open this .X file on Mesh Viewer if i look at the Road from up it will be shown but if i look from the road it will become dark (Black) !!!!!!!!  check this picture please  http://tinypic.com/im1c3k.jpg   ;  *bump*   