Constraint docs

[razer]

I read PDF docs (26-27 pages about constraints) and I am looking in RagDall and ForkLift Demo.
But I still have no clear understanding how contraints work.
First I thought I understand something but in RagDoll

Code: Select all

		localA.setIdentity(); localB.setIdentity();
		localA.getBasis().setEulerZYX(0,0,-M_PI_4*5); localA.setOrigin(btVector3(btScalar(-0.18), btScalar(-0.10), btScalar(0.)));
		localB.getBasis().setEulerZYX(0,0,-M_PI_4*5); localB.setOrigin(btVector3(btScalar(0.), btScalar(0.225), btScalar(0.)));
		coneC = new btConeTwistConstraint(*m_bodies[BODYPART_PELVIS], *m_bodies[BODYPART_LEFT_UPPER_LEG], localA, localB);
		coneC->setLimit(M_PI_4, M_PI_4, 0);
		m_joints[JOINT_LEFT_HIP] = coneC;
		coneC->setDbgDrawSize(CONSTRAINT_DEBUG_SIZE);

I do not understand why it should be rotated -M_PI_4*5.

I can't find page that shows how contraints are oriented by default.

Is it replica of Open Dynamics or Havok and I should look in docs for these engines?

Thanks