C++ btRigidBody::getInvInertiaTensorWorld方法代码示例

void btSliderConstraint::solveConstraintInt(btRigidBody& rbA, btSolverBody& bodyA,btRigidBody& rbB, btSolverBody& bodyB)
{
    int i;
    // linear
    btVector3 velA;
	bodyA.getVelocityInLocalPointObsolete(m_relPosA,velA);
    btVector3 velB;
	bodyB.getVelocityInLocalPointObsolete(m_relPosB,velB);
    btVector3 vel = velA - velB;
	for(i = 0; i < 3; i++)
    {
		const btVector3& normal = m_jacLin[i].m_linearJointAxis;
		btScalar rel_vel = normal.dot(vel);
		// calculate positional error
		btScalar depth = m_depth[i];
		// get parameters
		btScalar softness = (i) ? m_softnessOrthoLin : (m_solveLinLim ? m_softnessLimLin : m_softnessDirLin);
		btScalar restitution = (i) ? m_restitutionOrthoLin : (m_solveLinLim ? m_restitutionLimLin : m_restitutionDirLin);
		btScalar damping = (i) ? m_dampingOrthoLin : (m_solveLinLim ? m_dampingLimLin : m_dampingDirLin);
		// calcutate and apply impulse
		btScalar normalImpulse = softness * (restitution * depth / m_timeStep - damping * rel_vel) * m_jacLinDiagABInv[i];
		btVector3 impulse_vector = normal * normalImpulse;
		
		//rbA.applyImpulse( impulse_vector, m_relPosA);
		//rbB.applyImpulse(-impulse_vector, m_relPosB);
		{
			btVector3 ftorqueAxis1 = m_relPosA.cross(normal);
			btVector3 ftorqueAxis2 = m_relPosB.cross(normal);
			bodyA.applyImpulse(normal*rbA.getInvMass(), rbA.getInvInertiaTensorWorld()*ftorqueAxis1,normalImpulse);
			bodyB.applyImpulse(normal*rbB.getInvMass(), rbB.getInvInertiaTensorWorld()*ftorqueAxis2,-normalImpulse);
		}



		if(m_poweredLinMotor && (!i))
		{ // apply linear motor
			if(m_accumulatedLinMotorImpulse < m_maxLinMotorForce)
			{
				btScalar desiredMotorVel = m_targetLinMotorVelocity;
				btScalar motor_relvel = desiredMotorVel + rel_vel;
				normalImpulse = -motor_relvel * m_jacLinDiagABInv[i];
				// clamp accumulated impulse
				btScalar new_acc = m_accumulatedLinMotorImpulse + btFabs(normalImpulse);
				if(new_acc  > m_maxLinMotorForce)
				{
					new_acc = m_maxLinMotorForce;
				}
				btScalar del = new_acc  - m_accumulatedLinMotorImpulse;
				if(normalImpulse < btScalar(0.0))
				{
					normalImpulse = -del;
				}
				else
				{
					normalImpulse = del;
				}
				m_accumulatedLinMotorImpulse = new_acc;
				// apply clamped impulse
				impulse_vector = normal * normalImpulse;
				//rbA.applyImpulse( impulse_vector, m_relPosA);
				//rbB.applyImpulse(-impulse_vector, m_relPosB);

				{
					btVector3 ftorqueAxis1 = m_relPosA.cross(normal);
					btVector3 ftorqueAxis2 = m_relPosB.cross(normal);
					bodyA.applyImpulse(normal*rbA.getInvMass(), rbA.getInvInertiaTensorWorld()*ftorqueAxis1,normalImpulse);
					bodyB.applyImpulse(normal*rbB.getInvMass(), rbB.getInvInertiaTensorWorld()*ftorqueAxis2,-normalImpulse);
				}



			}
		}
    }
	// angular 
	// get axes in world space
	btVector3 axisA =  m_calculatedTransformA.getBasis().getColumn(0);
	btVector3 axisB =  m_calculatedTransformB.getBasis().getColumn(0);

	btVector3 angVelA;
	bodyA.getAngularVelocity(angVelA);
	btVector3 angVelB;
	bodyB.getAngularVelocity(angVelB);

	btVector3 angVelAroundAxisA = axisA * axisA.dot(angVelA);
	btVector3 angVelAroundAxisB = axisB * axisB.dot(angVelB);

	btVector3 angAorthog = angVelA - angVelAroundAxisA;
	btVector3 angBorthog = angVelB - angVelAroundAxisB;
	btVector3 velrelOrthog = angAorthog-angBorthog;
	//solve orthogonal angular velocity correction
	btScalar len = velrelOrthog.length();
	btScalar orthorImpulseMag = 0.f;

	if (len > btScalar(0.00001))
	{
		btVector3 normal = velrelOrthog.normalized();
		btScalar denom = rbA.computeAngularImpulseDenominator(normal) + rbB.computeAngularImpulseDenominator(normal);
		//velrelOrthog *= (btScalar(1.)/denom) * m_dampingOrthoAng * m_softnessOrthoAng;
		orthorImpulseMag = (btScalar(1.)/denom) * m_dampingOrthoAng * m_softnessOrthoAng;
//.........这里部分代码省略.........

btScalar btTranslationalLimitMotor::solveLinearAxis(
	btScalar timeStep,
	btScalar jacDiagABInv,
	btRigidBody& body1,const btVector3 &pointInA,
	btRigidBody& body2,const btVector3 &pointInB,
	int limit_index,
	const btVector3 & axis_normal_on_a,
	const btVector3 & anchorPos)
{

	///find relative velocity
	//    btVector3 rel_pos1 = pointInA - body1.getCenterOfMassPosition();
	//    btVector3 rel_pos2 = pointInB - body2.getCenterOfMassPosition();
	btVector3 rel_pos1 = anchorPos - body1.getCenterOfMassPosition();
	btVector3 rel_pos2 = anchorPos - body2.getCenterOfMassPosition();

	btVector3 vel1;
	body1.internalGetVelocityInLocalPointObsolete(rel_pos1,vel1);
	btVector3 vel2;
	body2.internalGetVelocityInLocalPointObsolete(rel_pos2,vel2);
	btVector3 vel = vel1 - vel2;

	btScalar rel_vel = axis_normal_on_a.dot(vel);



	/// apply displacement correction

	//positional error (zeroth order error)
	btScalar depth = -(pointInA - pointInB).dot(axis_normal_on_a);
	btScalar	lo = btScalar(-BT_LARGE_FLOAT);
	btScalar	hi = btScalar(BT_LARGE_FLOAT);

	btScalar minLimit = m_lowerLimit[limit_index];
	btScalar maxLimit = m_upperLimit[limit_index];

	//handle the limits
	if (minLimit < maxLimit)
	{
		{
			if (depth > maxLimit)
			{
				depth -= maxLimit;
				lo = btScalar(0.);

			}
			else
			{
				if (depth < minLimit)
				{
					depth -= minLimit;
					hi = btScalar(0.);
				}
				else
				{
					return 0.0f;
				}
			}
		}
	}

	btScalar normalImpulse= m_limitSoftness*(m_restitution*depth/timeStep - m_damping*rel_vel) * jacDiagABInv;




	btScalar oldNormalImpulse = m_accumulatedImpulse[limit_index];
	btScalar sum = oldNormalImpulse + normalImpulse;
	m_accumulatedImpulse[limit_index] = sum > hi ? btScalar(0.) : sum < lo ? btScalar(0.) : sum;
	normalImpulse = m_accumulatedImpulse[limit_index] - oldNormalImpulse;

	btVector3 impulse_vector = axis_normal_on_a * normalImpulse;
	//body1.applyImpulse( impulse_vector, rel_pos1);
	//body2.applyImpulse(-impulse_vector, rel_pos2);

	btVector3 ftorqueAxis1 = rel_pos1.cross(axis_normal_on_a);
	btVector3 ftorqueAxis2 = rel_pos2.cross(axis_normal_on_a);
	body1.internalApplyImpulse(axis_normal_on_a*body1.getInvMass(), body1.getInvInertiaTensorWorld()*ftorqueAxis1,normalImpulse);
	body2.internalApplyImpulse(axis_normal_on_a*body2.getInvMass(), body2.getInvInertiaTensorWorld()*ftorqueAxis2,-normalImpulse);




	return normalImpulse;
}