address PR comment and tune parameters for cloth

Author: xhan0619

examples/RoboticsLearning/GripperGraspExample.cpp

@@ -424,12 +424,13 @@ class GripperGraspExample : public CommonExampleInterface
 			m_robotSim.setGravity(btVector3(0, 0, -10));
 
 			m_robotSim.setGravity(btVector3(0, 0, -10));
-			b3RobotSimulatorLoadDeformableBodyArgs args(1, .01, 0.02);
-			args.m_springElasticStiffness = 1;
-			args.m_springDampingStiffness = .001;
-			args.m_springBendingStiffness = .2;
-			args.m_frictionCoeff = 2;
+			b3RobotSimulatorLoadDeformableBodyArgs args(2, .01, 0.006);
+			args.m_springElasticStiffness = .1;
+			args.m_springDampingStiffness = .0004;
+			args.m_springBendingStiffness = 1;
+			args.m_frictionCoeff = 1;
 			args.m_useSelfCollision = false;
+//			args.m_useFaceContact = true;
 			args.m_useBendingSprings = true;
 			args.m_startPosition.setValue(0, 0, 0);
 			args.m_startOrientation.setValue(0, 0, 1, 1);
@@ -475,6 +476,7 @@ class GripperGraspExample : public CommonExampleInterface
 			revoluteJoint2.m_jointType = ePoint2PointType;
 			m_robotSim.createConstraint(0, 2, 0, 4, &revoluteJoint1);
 			m_robotSim.createConstraint(0, 3, 0, 6, &revoluteJoint2);
+			m_robotSim.setNumSimulationSubSteps(8);
         }
 
 		if ((m_options & eSOFTBODY_MULTIBODY_COUPLING) != 0)

examples/SharedMemory/b3RobotSimulatorClientAPI_NoDirect.cpp

@@ -1178,8 +1178,14 @@ void b3RobotSimulatorClientAPI_NoDirect::loadDeformableBody(const std::string& f
 	b3LoadSoftBodySetScale(command, args.m_scale);
 	b3LoadSoftBodySetMass(command, args.m_mass);
 	b3LoadSoftBodySetCollisionMargin(command, args.m_collisionMargin);
-	b3LoadSoftBodyAddNeoHookeanForce(command, args.m_NeoHookeanMu, args.m_NeoHookeanLambda, args.m_NeoHookeanDamping);
-	b3LoadSoftBodyAddMassSpringForce(command, args.m_springElasticStiffness, args.m_springDampingStiffness);
+	if (args.m_NeoHookeanMu > 0)
+	{
+		b3LoadSoftBodyAddNeoHookeanForce(command, args.m_NeoHookeanMu, args.m_NeoHookeanLambda, args.m_NeoHookeanDamping);
+	}
+	if (args.m_springElasticStiffness > 0)
+	{
+		b3LoadSoftBodyAddMassSpringForce(command, args.m_springElasticStiffness, args.m_springDampingStiffness);
+	}
 	b3LoadSoftBodySetSelfCollision(command, args.m_useSelfCollision);
 	b3LoadSoftBodyUseFaceContact(command, args.m_useFaceContact);
 	b3LoadSoftBodySetFrictionCoefficient(command, args.m_frictionCoeff);

examples/SharedMemory/b3RobotSimulatorClientAPI_NoDirect.h

@@ -113,7 +113,16 @@ struct b3RobotSimulatorLoadDeformableBodyArgs
 	m_startOrientation(startOrn),
 	m_scale(scale),
 	m_mass(mass),
-	m_collisionMargin(collisionMargin)
+	m_collisionMargin(collisionMargin),
+	m_springElasticStiffness(-1),
+	m_springDampingStiffness(-1),
+	m_springBendingStiffness(-1),
+	m_NeoHookeanMu(-1),
+	m_NeoHookeanDamping(-1),
+	m_useSelfCollision(false),
+	m_useFaceContact(false),
+	m_useBendingSprings(false),
+	m_frictionCoeff(0)
 	{
 	}