Thursday, May 28, 2009

PhysX and DirectX 10

For the past week or so, I've been working on getting PhysX working in DirectX 10. I ported over my Shape3D class from my previous blog post to C++ in order to draw the boxes and spheres (no cylinders because PhysX doesn't have a cylinder shape).

I set up a simple scene with a ground plane (not rendered), normal Earth gravity, two boxes and a sphere. The space bar spawns new boxes at the origin and the Alt key spawns new spheres.

In my first implementation, the application would slow down to 20fps when I added about 75 shapes. I tracked down this slowdown to the creation of the vertex input layout each frame. Once I moved that out of the render loop, I could then have 1000 shapes in the scene and still maintain 30fps. I'm still trying to figure out if I can speed up the rendering even more because without rendering, the PhysX engine was able to handle 2000 shapes and maintain 60fps. I doubt I can speed it up much more though.

Here are some screenshots. Pretty simple, but the debug info helps to illustrate the speeds.

I have decided to share the Visual Studio 2008 project and source code to hopefully provide a nice starting point for others. I'm not using an official license or anything, but I'll state that is it free for whatever use you desire, be it commercial, hobby, or education.

Download the zip file: here

Next, I'm going to work on using static triangle meshes in PhysX to have a displaced sphere making up a planet, as well as using force fields to simulate planetary gravity.

1 comment:

AlextTesla said...

thanks for the source.Gonna use it to implement dx 10 and physx 3.2.