I'm working on a fairly simple terrain engine that needs to run on as wide a variety of machines as possible. I am in the process of implementing splatting and have got it working fine on my desktop, an XP 2000+ running XP and a pretty high end graphics card (nvidia 5200 se or something along those lines). I have written the program using Managed DirectX 9.0 Summer 2004 SDK and C# (VS 2003). Taking the same app and running it unchanged on my laptop with an old Rage Mobility (8 megs SDRam) causes some very strange behavior. It seems that the vertex buffers are fine, as I can render the vertices as pointlists without a problem. However, the index arrays don't seem to be working correctly, as the triangles being rendered jumps around as the viewpoint moves and never renders all the triangles (and renders many incorrectly). I've attached a few shots of the problem, along with a shot of the program running in reference mode on the laptop. The fact that it runs fine on my desktop and in reference mode suggests that it is a problem with the Mobility card. If anyone recognizes this behavior as a symptom of something (perhaps running out of memory? no errors from it..) or has any suggestions of how to fix it I'd appreciate it. I've tried several different driver sets (and they aren't easy to find for legacy laptop cards) and while they have given different results, none of which were correct. Problem Pictures:
What it should look like:

I am not sure about this, but I have heard that some cards do not support int (32bit) indexes, but only short (16bit) indexes. Which are you using?

I was using ints, changing it to shorts fixed the problem!

Thanks a ton, I don't know if I ever would have thought of that solution! Its too easy to write off the space difference between a short and an int when you're using modern hardware, but this older stuff is a bit more picky.

:-D

Sweet.