public LineJointDef()
{
Type = JointType.LineJoint;
localAnchor1.SetZero();
localAnchor2.SetZero();
localAxis1.Set(1.0f, 0.0f);
enableLimit = false;
lowerTranslation = 0.0f;
upperTranslation = 0.0f;
enableMotor = false;
maxMotorForce = 0.0f;
motorSpeed = 0.0f;
}