# Understanding HingeConstraint in jBullet

I'm using the java port of BulletPhysics engine jBullet. I'd like to make a joints between 2 triangles so that one edge of the first and one edge of the seconds act like a hinge.

But I don't understand how to use the HingeConstraint class because it lacks documentation. What pivotInA and pivotInB are? They are the pivot points of the hinge in respect to the object centre? And axisInA? How does it differs from axisInA?

For two triangles do I have to make 2 Hinge constrains in 2 vertex or 1 in the middle point of the 2 edges of the hinge?

Where can I find a simple working example of this?