Is there any physics engine SDK for iPhone/iPod touch and iPad?

Question

Is there any physics engine SDK for iPhone/iPod touch and iPad?

Answer 1

I've used the SIO2 engine for developing games on the iPhone, and it uses the open-source physics engine bullet. I'm not sure if all the soft-body features are available, but certainly the rigid body ones are. I don't know if anybody has written an Objective-C wrapper, but you certainly don't need one.

Answer 2

The Chipmunk engine is written in C, and they've even provided an Objective-C wrapper.

The Box2D engine is written in C++, and so it can be compiled/linked into an iPhone OS project by telling Xcode to treat it as Objective-C++.

Both are excellent. (I've only extensively used Box2D, but I've heard great things about Chipmunk too.)