free physics sdk

The two that come immediately to mind are ODE and Newton. I've never used the latter; the former is pretty good, though it doesn't stack up to commercial packages like Havok.

Thank you for your recomendation i will look into these ones now

In the realm of free physics engines, there are 5 options:
ODE
Newton
Tokamak
TrueAxis
PhysX SDK (formerly Novodex)

PhysX is fantastic, and should be the one you choose. The only issue with it is that commercial licensing is not public. Let me say this though -- if you're going commercial, you can afford it.

Newton is really great too. The API is really comfortable to work with. It used to be the slowest of the engines, but work over the course of the last two years has made it quite good in that regard too.

Tokamak's API is just ok. The thing about Tokamak is that it's blazing fast, but less stable than the other engines. Not a bad choice, though I'd go for Newton.

ODE is the only open source engine in the line up. It's a crappy engine that frequently explodes for no apparent reason. (In other words, it goes from stable to trashed very easily.) The API is terrible. I wouldn't recommend it at all unless you desperately need your physics engine's source for some reason.

I don't know anything about TrueAxis. It's the newest on the scene, I believe.

cheers i have looked at newton and it seems it has what i needed cheer all that helped

Bullet is another free open source physics engine.
http://bullet.sf.net

It is active under development, and includes concave and convex collision shapes, cylinders, COLLADA physics format import/export. For collision queries, it has convex sweep API, and experimental continuous collision detection (rotational).
It has projectfiles for Microsoft Visual Studio, and with CMake you can generate Mac OSX Xcode, Linux Kdevelop projectfiles etc.

Its Zlib license means free for commercial use without obligations.
But if you want to go commercial, non-free Havok is the best engine available.

Thanks,
Erwin

The continuous collision detection in bullet makes it a definite plus, but I heard that its being ported to ODE soon (rumour).

For the record; Concave, in general all kind of convex shapes, and continue collision are ordinary and trivial functionality supported by any physics engine.
So simple and ordinary that most physics engines do not even bother list it as main feature.

Quote:

Original post by jovani For the record; Concave, in general all kind of convex shapes, and continue collision are ordinary and trivial functionality supported by any physics engine.

Implementing robust, efficient (memory + performance) swept collision detection between arbitrary shapes is not (a) ordinary (b) trivial (c) supported by any physics SDK apart from the extraordinarily non-trivial ones :)