Conveyor belt

[josemarin]

Hello!

It's possible to create a conveyor belt using Bullet?

Thanks for any tip.

Jose

[Zimbarbo]

This is just one idea; I guess you could get a collection of static objects, and push them along a path. When one of them reaches the end, move it back to the start. You would also have to put them into their own group so they don't interact, and make them small enough so when they get moved back to the start, it doesn't shift the belt over. You can't just 'move' them either, you would have to make a slide constraint. The further question I have is if it is possible to have a moving rigid that can't be altered by others? If so, this would be one viable solution.

The criteria to make this work are the same to do any time of automatic environment, like elevators. Which is something else I need to check into for my side-scroller.

[Erwin Coumans]

You can move kinematic objects around (static and kinematic objects don't interact by default). See CcdPhysicsDemo for how to use kinematic objects (there is a define at the top).
There are other options, that simlate parts of the conveyor belt with moving/rotating rigidbodies and constraints.

Best option is to use a custom friction model, that fakes the velocity so objects slide over a surface (conveyor). This is more tricky, so a sample should be made to show its usage.

Hope this helps,
Erwin

[Zimbarbo]

I am looking at the contraint demo for C#. One of them is ball joint that always spins around, and can not be stopped. Is this due to the call to EnableAngularMotor? If so, it looks like it is only available on hinge joints. If I wanted to do something like an elevator, I wouldn't just want to 'move' the object every update because it would just be put into an overlapping position with my dynamic objects. I would think I would want to do something like that Motor call on the hinge, except do it on a slider. I am looking through the code now, but I haven't seen anything yet.