The Best Physic Engine for commercial,multiplatform project?

nomad · Post by **nomad** » Sun Dec 10, 2006 12:01 pm

If you want an open source engine, then I'd recommend Bullet over ODE.
I gave up on ODE due to the inaccuracies of the solver. Yes, ODE is slightly faster but Bullet is being actively developed and has the ++promise++ of continuous collision detection (I think you can already do continuous convex casts in Bullet). And Bullet is very easy to use once you get into it.

Eternl Knight · Post by **Eternl Knight** » Mon Dec 11, 2006 1:05 am

You can already do continuous collision detection in Bullet. The work being done there is on automatic stepping of the physics engine using it (i.e. changing the time-steps based on the collision time).

Bullet is relatively easy to use, and is right now hosting a competition for a PS3 or Wii. Basically, the comp is to show off Bullet by having entrants use it in a game/demo. I'm going to give it a whirl

--EK

TheRLG · Post by **TheRLG** » Mon Dec 11, 2006 2:41 am

I hadn't really heard of Bullet, after looking, I am fairly impressed. It seems worthy of a trial, but I don't know how easy to use it is because I havent downloaded it yet! I think Bullet and PhysX are our leading reccomendations right now...

nomad · Post by **nomad** » Mon Dec 11, 2006 5:20 pm

RabidLockerGnome wrote:I hadn't really heard of Bullet, after looking, I am fairly impressed. It seems worthy of a trial, but I don't know how easy to use it is because I havent downloaded it yet!

Bullet is really easy. It has plenty of examples that use OpenGL, but I'd be happy to put a simple Irrlicht / Bullet 'hello world' tutorial together if that would help.

nomad · Post by **nomad** » Wed Dec 13, 2006 7:35 pm

I'd be happy to put a simple Irrlicht / Bullet 'hello world' tutorial together if that would help.

No takers, eh? (and I'm quoting myself, thats just sad)
Well I'm putting an Irrlicht-Bullet demo / codebase together anyway, demonstrating collision shapes, reusing collision geometry etc. Might be helpful to anyone starting out with Bullet.

cassini · Post by **cassini** » Fri Dec 22, 2006 10:40 pm

Eternl Knight wrote: Fastest is a point of contention, so I won't go into it in detail. Suffice to say that the speed of the engine must be weighed against the accuracy of the physics solution. ODE is pretty good for this, as is Newton & Bullet - all have their own ways of maintaining plausible accuracy (ODE will remove angular momentum, Newton applies damping, etc). ….
--EK

Just for the record, I do not think this is correct information, Dampening in Newton is optional, it is not used for accuracy, It just happens that the default value is not zero, but you can set it to zero on creation of rigid bodies.
This is what the docs says about that.

NewtonBodySetLinearDamping (const NewtonBody* body, dFloat linearDamp);
NewtonBodySetAngularDamping (const NewtonBody* body, const dFloat* angularDamp);

The dampening viscous friction force is added to the external force applied to the body every frame before going to the solver-integrator. This force is proportional to the square of the magnitude of the velocity to the body in the opposite direction of the velocity of the body. An application can set linearDamp to zero when the application takes control of the external forces and torque applied to the body, should the application desire to have absolute control of the forces over that body. However, it is recommended that the linearDamp coefficient is set to a non-zero value for the majority of background bodies. This saves the application from having to control these forces and also prevents the integrator from adding very large velocities to a body.

Frankly with PhysX been free for all kind of projects, I think the best of the free engines is closer to second place than second place is from physX. The comparison made sense when PhysX was not available but not anymore.

Nadro · Post by **Nadro** » Mon Jan 01, 2007 11:46 am

Where is the Bullet+IrrLicht 'Hello World'?

omaremad · Post by **omaremad** » Mon Jan 01, 2007 4:23 pm

Search for OPAL it makes ode reallly easy there is even some tri mesh conversion code for irrlicht on its wiki.

lostclimategames · Post by **lostclimategames** » Mon Jan 01, 2007 6:13 pm

i am still looking forward to the tutorial on bullet and irrlicht implementation

Eternl Knight · Post by **Eternl Knight** » Tue Jan 02, 2007 7:55 pm

There is no "tutorial", but a quick glance at the Bullet forums will give you the implementation of a demo.

--EK

nomad · Post by **nomad** » Wed Jan 03, 2007 4:24 pm

lostclimategames wrote:i am still looking forward to the tutorial on bullet and irrlicht implementation

I've added an HTML tutorial to my original hello world example. It's done in the same format as the Irrlicht examples. You will need to change some of the compiler settings if you are using a newer version of Bullet than 2.40

Hope it's helpful. Get it here: http://www.sideshoot.com/downloads/irrl ... oworld.zip