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combat friction drift in positionCorrect by changing velocity and change it back (effectively only changing position)

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This commit is contained in:
Xuchen Han
2019-07-23 12:15:23 -07:00
parent a90cad2a96
commit 243b9fc8c7
15 changed files with 291 additions and 152 deletions
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23
examples/DeformableContact/DeformableContact.cpp
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@@ -54,13 +54,6 @@ class DeformableContact : public CommonMultiBodyBase
btMultiBody* m_multiBody;
btAlignedObjectArray<btMultiBodyJointFeedback*> m_jointFeedbacks;
public:
struct TetraBunny
{
#include "../SoftDemo/bunny.inl"
};
DeformableContact(struct GUIHelperInterface* helper)
: CommonMultiBodyBase(helper)
{
@@ -147,7 +140,7 @@ void DeformableContact::initPhysics()
btTransform groundTransform;
groundTransform.setIdentity();
groundTransform.setOrigin(btVector3(0, -40, 0));
groundTransform.setRotation(btQuaternion(btVector3(1, 0, 0), SIMD_PI * 0.0));
groundTransform.setRotation(btQuaternion(btVector3(1, 0, 0), SIMD_PI * 0.1));
//We can also use DemoApplication::localCreateRigidBody, but for clarity it is provided here:
btScalar mass(0.);
@@ -170,16 +163,16 @@ void DeformableContact::initPhysics()
{
bool damping = true;
bool gyro = true;
int numLinks = 3;
bool damping = false;
bool gyro = false;
int numLinks = 0;
bool spherical = true; //set it ot false -to use 1DoF hinges instead of 3DoF sphericals
bool canSleep = false;
bool selfCollide = true;
btVector3 linkHalfExtents(1, 1, 1);
btVector3 baseHalfExtents(1, 1, 1);
btMultiBody* mbC = createFeatherstoneMultiBody_testMultiDof(m_dynamicsWorld, numLinks, btVector3(0.f, 10.f,0.f), linkHalfExtents, baseHalfExtents, spherical, g_floatingBase);
btMultiBody* mbC = createFeatherstoneMultiBody_testMultiDof(m_dynamicsWorld, numLinks, btVector3(0.f, 2.f,0.f), linkHalfExtents, baseHalfExtents, spherical, g_floatingBase);
mbC->setCanSleep(canSleep);
mbC->setHasSelfCollision(selfCollide);
@@ -216,12 +209,13 @@ void DeformableContact::initPhysics()
// create a patch of cloth
{
const btScalar s = 6;
const btScalar s = 4;
btSoftBody* psb = btSoftBodyHelpers::CreatePatch(getDeformableDynamicsWorld()->getWorldInfo(), btVector3(-s, 0, -s),
btVector3(+s, 0, -s),
btVector3(-s, 0, +s),
btVector3(+s, 0, +s),
20,20,
// 20,20,
3,3,
1 + 2 + 4 + 8, true);
psb->getCollisionShape()->setMargin(0.25);
@@ -232,7 +226,6 @@ void DeformableContact::initPhysics()
psb->m_cfg.kCHR = 1; // collision hardness with rigid body
psb->m_cfg.kDF = 0;
getDeformableDynamicsWorld()->addSoftBody(psb);
}
m_guiHelper->autogenerateGraphicsObjects(m_dynamicsWorld);

21
examples/DeformableDemo/DeformableDemo.cpp
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@@ -105,15 +105,15 @@ public:
// }
btTransform startTransform;
startTransform.setIdentity();
startTransform.setOrigin(btVector3(1, 2, 1));
startTransform.setOrigin(btVector3(1, 1.5, 1));
createRigidBody(mass, startTransform, shape[0]);
startTransform.setOrigin(btVector3(1, 2, -1));
startTransform.setOrigin(btVector3(1, 1.5, -1));
createRigidBody(mass, startTransform, shape[0]);
startTransform.setOrigin(btVector3(-1, 2, 1));
startTransform.setOrigin(btVector3(-1, 1.5, 1));
createRigidBody(mass, startTransform, shape[0]);
startTransform.setOrigin(btVector3(-1, 2, -1));
startTransform.setOrigin(btVector3(-1, 1.5, -1));
createRigidBody(mass, startTransform, shape[0]);
startTransform.setOrigin(btVector3(0, 4, 0));
startTransform.setOrigin(btVector3(0, 3.5, 0));
createRigidBody(mass, startTransform, shape[0]);
}
@@ -182,7 +182,7 @@ void DeformableDemo::initPhysics()
btTransform groundTransform;
groundTransform.setIdentity();
groundTransform.setOrigin(btVector3(0, -30, 0));
groundTransform.setOrigin(btVector3(0, -32, 0));
groundTransform.setRotation(btQuaternion(btVector3(1, 0, 0), SIMD_PI * 0.));
//We can also use DemoApplication::localCreateRigidBody, but for clarity it is provided here:
btScalar mass(0.);
@@ -206,7 +206,7 @@ void DeformableDemo::initPhysics()
// create a piece of cloth
{
bool onGround = true;
bool onGround = false;
const btScalar s = 4;
btSoftBody* psb = btSoftBodyHelpers::CreatePatch(getDeformableDynamicsWorld()->getWorldInfo(), btVector3(-s, 0, -s),
btVector3(+s, 0, -s),
@@ -222,13 +222,14 @@ void DeformableDemo::initPhysics()
btVector3(+s, 0, -s),
btVector3(-s, 0, +s),
btVector3(+s, 0, +s),
20,20,
// 20,20,
2,2,
0, true);
psb->getCollisionShape()->setMargin(0.1);
psb->generateBendingConstraints(2);
psb->setTotalMass(10);
psb->setSpringStiffness(10);
psb->setTotalMass(1);
psb->setSpringStiffness(1);
psb->setDampingCoefficient(0.01);
psb->m_cfg.kKHR = 1; // collision hardness with kinematic objects
psb->m_cfg.kCHR = 1; // collision hardness with rigid body

136
examples/Pinch/Pinch.cpp
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@@ -73,9 +73,9 @@ public:
void resetCamera()
{
float dist = 25;
float pitch = -45;
float pitch = -30;
float yaw = 100;
float targetPos[3] = {0, -3, 0};
float targetPos[3] = {0, -0, 0};
m_guiHelper->resetCamera(dist, yaw, pitch, targetPos[0], targetPos[1], targetPos[2]);
}
@@ -137,17 +137,56 @@ void dynamics(btScalar time, btDeformableRigidDynamicsWorld* world)
return;
btRigidBody* rb0 = rbs[0];
btScalar pressTime = 0.9;
btScalar liftTime = 2.5;
btScalar shiftTime = 3.5;
btScalar holdTime = 4.5*1000;
btScalar dropTime = 5.3*1000;
btTransform rbTransform;
rbTransform.setIdentity();
btVector3 translation = btVector3(0.5,3,4);
btVector3 velocity = btVector3(0,5,0);
btVector3 translation;
btVector3 velocity;
btVector3 initialTranslationLeft = btVector3(0.5,3,4);
btVector3 initialTranslationRight = btVector3(0.5,3,-4);
btVector3 pinchVelocityLeft = btVector3(0,0,-2);
btVector3 pinchVelocityRight = btVector3(0,0,2);
btVector3 liftVelocity = btVector3(0,5,0);
btVector3 shiftVelocity = btVector3(0,0,5);
btVector3 holdVelocity = btVector3(0,0,0);
btVector3 openVelocityLeft = btVector3(0,0,4);
btVector3 openVelocityRight = btVector3(0,0,-4);
if (time < pressTime)
{
velocity = btVector3(0,0,-2);
translation += velocity * time;
velocity = pinchVelocityLeft;
translation = initialTranslationLeft + pinchVelocityLeft * time;
}
else if (time < liftTime)
{
velocity = liftVelocity;
translation = initialTranslationLeft + pinchVelocityLeft * pressTime + liftVelocity * (time - pressTime);
}
else if (time < shiftTime)
{
velocity = shiftVelocity;
translation = initialTranslationLeft + pinchVelocityLeft * pressTime + liftVelocity * (liftTime-pressTime) + shiftVelocity * (time - liftTime);
}
else if (time < holdTime)
{
velocity = btVector3(0,0,0);
translation = initialTranslationLeft + pinchVelocityLeft * pressTime + liftVelocity * (liftTime-pressTime) + shiftVelocity * (shiftTime - liftTime) + holdVelocity * (time - shiftTime);
}
else if (time < dropTime)
{
velocity = openVelocityLeft;
translation = initialTranslationLeft + pinchVelocityLeft * pressTime + liftVelocity * (liftTime-pressTime) + shiftVelocity * (shiftTime - liftTime) + holdVelocity * (holdTime - shiftTime)+ openVelocityLeft * (time - holdTime);
}
else
translation += btVector3(0,0,-2) * pressTime + (time-pressTime)*velocity;
{
velocity = holdVelocity;
translation = initialTranslationLeft + pinchVelocityLeft * pressTime + liftVelocity * (liftTime-pressTime) + shiftVelocity * (shiftTime - liftTime) + holdVelocity * (holdTime - shiftTime)+ openVelocityLeft * (dropTime - holdTime);
}
rbTransform.setOrigin(translation);
rbTransform.setRotation(btQuaternion(btVector3(1, 0, 0), SIMD_PI * 0));
rb0->setCenterOfMassTransform(rbTransform);
@@ -155,23 +194,45 @@ void dynamics(btScalar time, btDeformableRigidDynamicsWorld* world)
rb0->setLinearVelocity(velocity);
btRigidBody* rb1 = rbs[1];
translation = btVector3(0.5,3,-4);
velocity = btVector3(0,5,0);
if (time < pressTime)
{
velocity = btVector3(0,0,2);
translation += velocity * time;
velocity = pinchVelocityRight;
translation = initialTranslationRight + pinchVelocityRight * time;
}
else if (time < liftTime)
{
velocity = liftVelocity;
translation = initialTranslationRight + pinchVelocityRight * pressTime + liftVelocity * (time - pressTime);
}
else if (time < shiftTime)
{
velocity = shiftVelocity;
translation = initialTranslationRight + pinchVelocityRight * pressTime + liftVelocity * (liftTime-pressTime) + shiftVelocity * (time - liftTime);
}
else if (time < holdTime)
{
velocity = btVector3(0,0,0);
translation = initialTranslationRight + pinchVelocityRight * pressTime + liftVelocity * (liftTime-pressTime) + shiftVelocity * (shiftTime - liftTime) + holdVelocity * (time - shiftTime);
}
else if (time < dropTime)
{
velocity = openVelocityRight;
translation = initialTranslationRight + pinchVelocityRight * pressTime + liftVelocity * (liftTime-pressTime) + shiftVelocity * (shiftTime - liftTime) + holdVelocity * (holdTime - shiftTime)+ openVelocityRight * (time - holdTime);
}
else
translation += btVector3(0,0,2) * pressTime + (time-pressTime)*velocity;
{
velocity = holdVelocity;
translation = initialTranslationRight + pinchVelocityRight * pressTime + liftVelocity * (liftTime-pressTime) + shiftVelocity * (shiftTime - liftTime) + holdVelocity * (holdTime - shiftTime)+ openVelocityRight * (dropTime - holdTime);
}
rbTransform.setOrigin(translation);
rbTransform.setRotation(btQuaternion(btVector3(1, 0, 0), SIMD_PI * 0));
rb1->setCenterOfMassTransform(rbTransform);
rb1->setAngularVelocity(btVector3(0,0,0));
rb1->setLinearVelocity(velocity);
rb0->setFriction(2);
rb1->setFriction(2);
rb0->setFriction(20);
rb1->setFriction(20);
}
void Pinch::initPhysics()
@@ -194,7 +255,7 @@ void Pinch::initPhysics()
m_dynamicsWorld->setGravity(btVector3(0, -10, 0));
getDeformableDynamicsWorld()->getWorldInfo().m_gravity.setValue(0, -10, 0);
getDeformableDynamicsWorld()->before_solver_callbacks.push_back(dynamics);
getDeformableDynamicsWorld()->m_beforeSolverCallbacks.push_back(dynamics);
m_guiHelper->createPhysicsDebugDrawer(m_dynamicsWorld);
//create a ground
@@ -229,21 +290,58 @@ void Pinch::initPhysics()
// create a soft block
{
btScalar verts[24] = {0.f, 0.f, 0.f,
1.f, 0.f, 0.f,
0.f, 1.f, 0.f,
0.f, 0.f, 1.f,
1.f, 1.f, 0.f,
0.f, 1.f, 1.f,
1.f, 0.f, 1.f,
1.f, 1.f, 1.f
};
int triangles[60] = {0, 6, 3,
0,1,6,
7,5,3,
7,3,6,
4,7,6,
4,6,1,
7,2,5,
7,4,2,
0,3,2,
2,3,5,
0,2,4,
0,4,1,
0,6,5,
0,6,4,
3,4,2,
3,4,7,
2,7,3,
2,7,1,
4,5,0,
4,5,6,
};
// btSoftBody* psb = btSoftBodyHelpers::CreateFromTriMesh(getDeformableDynamicsWorld()->getWorldInfo(), &verts[0], &triangles[0], 20);
////
btSoftBody* psb = btSoftBodyHelpers::CreateFromTetGenData(getDeformableDynamicsWorld()->getWorldInfo(),
TetraCube::getElements(),
0,
TetraCube::getNodes(),
false, true, true);
getDeformableDynamicsWorld()->addSoftBody(psb);
psb->scale(btVector3(2, 2, 2));
psb->translate(btVector3(0, 4, 0));
psb->getCollisionShape()->setMargin(0.1);
psb->setTotalMass(1);
psb->setSpringStiffness(10);
psb->setDampingCoefficient(0.01);
// psb->scale(btVector3(5, 5, 5));
// psb->translate(btVector3(-2.5, 4, -2.5));
// psb->getCollisionShape()->setMargin(0.1);
// psb->setTotalMass(1);
psb->setSpringStiffness(4);
psb->setDampingCoefficient(0.02);
psb->m_cfg.kKHR = 1; // collision hardness with kinematic objects
psb->m_cfg.kCHR = 1; // collision hardness with rigid body
psb->m_cfg.kDF = 0.5;
psb->m_cfg.kDF = 2;
getDeformableDynamicsWorld()->addSoftBody(psb);
// add a grippers
createGrip();
}

4
examples/VolumetricDeformable/VolumetricDeformable.cpp
View File

@@ -77,8 +77,8 @@ public:
void stepSimulation(float deltaTime)
{
//use a smaller internal timestep, there are stability issues
float internalTimeStep = 1. / 240.f;
m_dynamicsWorld->stepSimulation(deltaTime, 4, internalTimeStep);
float internalTimeStep = 1. / 480.f;
m_dynamicsWorld->stepSimulation(deltaTime, 8, internalTimeStep);
}
void createStaticBox(const btVector3& halfEdge, const btVector3& translation)