Coder Corner

This last test (“SeaOfStaticBoxes3”) didn’t fit in any category, so I kept it for the end. It does not actually do anything, it only creates a massive amount of static boxes (255*255). There is otherwise no dynamic objects in the scene, nothing to simulate at all.

There are 2 things to notice here. The first one is memory usage. We went from 94Mb to 54Mb to 39Mb, from one PhysX version to another. That’s the right direction here!

The other thing is the time it takes to simulate an empty scene. As you can see, it doesn’t take much time with PhysX – as it should. Bullet however, for some reason, takes a massive amount of time here. On my home PC, Bullet takes about 34ms (!?) to simulate this empty scene. I double-checked everything, looking for something I did wrong, but it turns out the problem has already been reported on the Bullet forums. I think this should be fixed and work out-of-the-box.

In any case, I am not here to fix Bullet issues. The point is simply, again, that contrary to what people may still believe, PhysX is actually very optimized and a perfectly fine CPU physics engine. In fact, if some competitors would not prevent me from publishing the results, I would happily show you that it often beats everybody else. I invite curious readers to create their own benchmarks and see for themselves.

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This report is currently incomplete: it did not talk about CCD, or multithreaded simulations, or overlap tests. It also barely scratched the surface of what these physics engines have to offer: I did not talk about character controllers, vehicles, the performance of binary deserialization, or any of those more advanced topics.

As you can easily imagine, I’d need to write a book to cover all this, not just some blog posts.

However I think these posts may reach their limited goal, which is simply to show with very basic tests that:

• PhysX is getting faster all the time
• PhysX is very well optimized, thank you very much

This entry was posted on Saturday, May 11th, 2013 at 4:14 pm and is filed under Physics. You can follow any responses to this entry through the RSS 2.0 feed. Both comments and pings are currently closed.