Real-Time Physics Simulation Forum

I think gears are out of the scope of a realtime simulation. I would fudge them (Make them non-colliding and manually rotate them at the proper velocities) and forget about trying to simulate real intermeshing. As you said, the teeth will end up teleporting through each other, it would only be possi...

What I do is, after each physics step, there's a function like "getOpenGLMatrix" in the transform of each rigid body. I call that function for every body that I need to render, then send it straight to OpenGL.

The cylinder will never change shape, but it might be interpenetrating slightly.
I think you could try increasing the restitution or something.

No, the Bullet world is separate from the graphics world. You have two worlds, one for physics, one for graphics. Every frame you update the graphics objects based on their corresponding physics objects. Then you draw the graphics objects. Bullet has nothing at all to do with drawing, it just tells ...

It should be possible to use Bullet with XNA if XNA's language (C#?) has a binding to Bullet. At worst, you will have to move transforms out of Bullet and into XNA just like other engines do. No idea about exporting physics from Blender. I have very simple physics models, so I just create them progr...

For guns you can usually get away with raycasting unless you're trying to simulate a sniper rifle with realistic delay over a huge range. You should look for btDiscreteDynamicsWorld's raycast functions. If you want some bullet delay or drop, you can do multiple raycasts spread over several frames, b...

I would give this guy a quick try before anything complex:

http://bulletphysics.com/Bullet/BulletF ... e5051e1a5a

btCollisionObject is a superclass of btRigidBody, so this function is available to all btRigidBodies.

Don't think of it as adding physics to a graphics object. Think of it as creating a physics world, and then pasting a graphics object on top of its corresponding physics object. There is usually a pretty wide separation between how something reacts physically and how it looks, and it's really the ph...

Heiko wrote:I have solved the problem. All I needed to do was a `updateAabbs' on the world after something changed.

Huh, I might have had that problem earlier and not noticed. Are you supposed to call that after you move an object manually?

I see you are setting the transform from an OpenGL matrix. Is it possible that this matrix scales your graphics objects? I'm not sure how Bullet supports scaling as I have never tried to scale something, and my unscaled objects seem to pick fine using the same approach you use here.

To slow it down you might use a smaller step size.

That also confused me, but I see it was a third-party, not Microsoft.
Also, MAC is some kind of networking term, you are thinking of Macintosh.

Yeah, this happened with me too, here's what I did: Before you delete a cube, get its islandTag (This is in the documentation for btRigidBody, I think) Delete the cube Iterate over all your other cubes. If a cube has the same islandTag, then that means it was in the same island, and it might be affe...

I wonder if you shouldn't be calling btDiscreteDynamicsWorld::removeRigidBody() instead of removeCollisionObject?

Do you get them immediately, or after the main loop exits?