Added btMultiBodyPoint2Point, it can be used between btMultiBody vs btMultiBody or btMultiBody vs btRigidBody

Allow picking of btMultiBody, using a btMultiBodyPoint2Point constraint, with limited strength to avoid adding too much energy to the system (= blowup) Add btMultiBodyJointMotor, it can be used in combination with joint limit (just add the joint limit after the motor, to avoid jitter)
2013-10-05 01:46:32 +00:00
parent 2fb686b937
commit 488dd44835
18 changed files with 1418 additions and 475 deletions
--- a/src/BulletDynamics/Featherstone/btMultiBodyPoint2Point.cpp
+++ b/src/BulletDynamics/Featherstone/btMultiBodyPoint2Point.cpp
@@ -0,0 +1,138 @@
+/*
+Bullet Continuous Collision Detection and Physics Library
+Copyright (c) 2013 Erwin Coumans  http://bulletphysics.org
+
+This software is provided 'as-is', without any express or implied warranty.
+In no event will the authors be held liable for any damages arising from the use of this software.
+Permission is granted to anyone to use this software for any purpose, 
+including commercial applications, and to alter it and redistribute it freely, 
+subject to the following restrictions:
+
+1. The origin of this software must not be misrepresented; you must not claim that you wrote the original software. If you use this software in a product, an acknowledgment in the product documentation would be appreciated but is not required.
+2. Altered source versions must be plainly marked as such, and must not be misrepresented as being the original software.
+3. This notice may not be removed or altered from any source distribution.
+*/
+
+///This file was written by Erwin Coumans
+
+#include "btMultiBodyPoint2Point.h"
+#include "btMultiBodyLinkCollider.h"
+#include "BulletDynamics/Dynamics/btRigidBody.h"
+
+btMultiBodyPoint2Point::btMultiBodyPoint2Point(btMultiBody* body, int link, btRigidBody* bodyB, const btVector3& pivotInA, const btVector3& pivotInB)
+	:btMultiBodyConstraint(body,0,link,-1,3,false),
+	m_rigidBodyA(0),
+	m_rigidBodyB(bodyB),
+	m_pivotInA(pivotInA),
+	m_pivotInB(pivotInB),
+	m_maxAppliedImpulse(1e30f)
+{
+}
+
+btMultiBodyPoint2Point::btMultiBodyPoint2Point(btMultiBody* bodyA, int linkA, btMultiBody* bodyB, int linkB, const btVector3& pivotInA, const btVector3& pivotInB)
+	:btMultiBodyConstraint(bodyA,bodyB,linkA,linkB,3,false),
+	m_rigidBodyA(0),
+	m_rigidBodyB(0),
+	m_pivotInA(pivotInA),
+	m_pivotInB(pivotInB),
+	m_maxAppliedImpulse(1e30f)
+{
+}
+
+
+btMultiBodyPoint2Point::~btMultiBodyPoint2Point()
+{
+}
+
+
+int btMultiBodyPoint2Point::getIslandIdA() const
+{
+	if (m_rigidBodyA)
+		return m_rigidBodyA->getIslandTag();
+
+	if (m_bodyA)
+	{
+		btMultiBodyLinkCollider* col = m_bodyA->getBaseCollider();
+		if (col)
+			return col->getIslandTag();
+		for (int i=0;i<m_bodyA->getNumLinks();i++)
+		{
+			if (m_bodyA->getLink(i).m_collider)
+				return m_bodyA->getLink(i).m_collider->getIslandTag();
+		}
+	}
+	return -1;
+}
+
+int btMultiBodyPoint2Point::getIslandIdB() const
+{
+	if (m_rigidBodyB)
+		return m_rigidBodyB->getIslandTag();
+	if (m_bodyB)
+	{
+		btMultiBodyLinkCollider* col = m_bodyB->getBaseCollider();
+		if (col)
+			return col->getIslandTag();
+
+		for (int i=0;i<m_bodyB->getNumLinks();i++)
+		{
+			col = m_bodyB->getLink(i).m_collider;
+			if (col)
+				return col->getIslandTag();
+		}
+	}
+	return -1;
+}
+
+
+
+void btMultiBodyPoint2Point::createConstraintRows(btMultiBodyConstraintArray& constraintRows,
+		btMultiBodyJacobianData& data,
+		const btContactSolverInfo& infoGlobal)
+{
+
+//	int i=1;
+	for (int i=0;i<3;i++)
+	{
+
+		btMultiBodySolverConstraint& constraintRow = constraintRows.expandNonInitializing();
+
+		constraintRow.m_solverBodyIdB = 0;
+		btVector3 contactNormalOnB(0,0,0);
+		contactNormalOnB[i] = -1;
+
+		btScalar penetration = 0;
+
+		 // Convert local points back to world
+		btVector3 pivotAworld = m_pivotInA;
+		if (m_rigidBodyA)
+		{
+			pivotAworld = m_rigidBodyA->getCenterOfMassTransform()*m_pivotInA;
+		} else
+		{
+			if (m_bodyA)
+				pivotAworld = m_bodyA->localPosToWorld(m_linkA, m_pivotInA);
+		}
+		btVector3 pivotBworld = m_pivotInB;
+		if (m_rigidBodyB)
+		{
+			pivotBworld = m_rigidBodyB->getCenterOfMassTransform()*m_pivotInB;
+		} else
+		{
+			if (m_bodyB)
+				pivotBworld = m_bodyB->localPosToWorld(m_linkB, m_pivotInB);
+		}
+		btScalar position = (pivotAworld-pivotBworld).dot(contactNormalOnB);
+		btScalar relaxation = 1.f;
+		fillMultiBodyConstraintMixed(constraintRow, data,
+																 contactNormalOnB,
+																 pivotAworld, pivotBworld, 
+																 position,
+																 infoGlobal,
+																 relaxation,
+																 false);
+		constraintRow.m_lowerLimit = -m_maxAppliedImpulse;
+		constraintRow.m_upperLimit = m_maxAppliedImpulse;
+
+	}
+}