Joints and stuff


First things first, I'm new to jME and I must say that its absolutely amazing!!

However, I have a slight problem, I want to use Ball Joints and Hinges but I'm not sure how to create one, I have managed to create a normal Joint and attach 2 JointRotationalAxis' to it, is this the same thing as a BallJoint i.e.

Joint with one rotational axis = hinge??

Joint with two rotational axis = ball joint??

is that correct??

Also how do I add friction into the simulation?

Thanks in advance

Welcome to the forums :slight_smile:

Ball joint = 3 rotational axes

Hinge2 or Universal = 2 rotational axes

You should have friction in any application right away. You can change friction by changing the material. If you create new material you have to define friction for each material pair that could contact.

What is not in there yet is rolling friction (for rolling spheres or wheels) - do you mean that?

Thanks for the reply  :smiley:

For what I'm using jME Physics for, friction on non-spherical objects should be fine. Thanks for your help  :smiley:

OK I've got a little further on in my little project but I have another question…

I see that its possible to position a joint anywhere on/in the first object by using setAnchor(Vector3f), is there a way of setting the anchor on the second object? I've looked at all the examples/tests/tutorials but none of them set an anchor on the second object.

Thanks in advance

For some joint implementations you can change the anchor to be relative to the second object, but there is always only one anchor. The initial relative position of the objects decide on the joint 'length' or 'second anchor'.

That sounds great!

My experience is mostly in genetic algorithms, neural networks (CTRNNs etc) and complex systems such as cellula automata and L-Systems. I'm confident we could implement these techniques in jME!

I'm not sure how much you've already got done or even what kinds of things you want to implement etc. Is there an area were we can post ideas/documents etc??

Haha I posted that last message to the wrong place, it was meant to be in the AI section! Doh!

Thats what happens when you have to many windows open kids haha