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Code Issues Releases Wiki Activity

code clean up + check in examples

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This commit is contained in:
Xuchen Han 2019-07-18 11:34:06 -07:00
parent 3430192db7
commit dc10336d45
18 changed files with 1552 additions and 412 deletions
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6
examples/BasicDemo/BasicExample.cpp
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@ -16,9 +16,9 @@ subject to the following restrictions:
#include "BasicExample.h"
#include "btBulletDynamicsCommon.h"
#define ARRAY_SIZE_Y 5
#define ARRAY_SIZE_X 5
#define ARRAY_SIZE_Z 5
#define ARRAY_SIZE_Y 1
#define ARRAY_SIZE_X 1
#define ARRAY_SIZE_Z 1
#include "LinearMath/btVector3.h"
#include "LinearMath/btAlignedObjectArray.h"

412
examples/DeformableContact/DeformableContact.cpp Normal file
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@ -0,0 +1,412 @@
/*
Bullet Continuous Collision Detection and Physics Library
Copyright (c) 2003-2006 Erwin Coumans http://continuousphysics.com/Bullet/
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.
*/
///create 125 (5x5x5) dynamic object
#define ARRAY_SIZE_X 5
#define ARRAY_SIZE_Y 5
#define ARRAY_SIZE_Z 5
//maximum number of objects (and allow user to shoot additional boxes)
#define MAX_PROXIES (ARRAY_SIZE_X * ARRAY_SIZE_Y * ARRAY_SIZE_Z + 1024)
///scaling of the objects (0.1 = 20 centimeter boxes )
#define SCALING 1.
#define START_POS_X -5
#define START_POS_Y -5
#define START_POS_Z -3
#include "DeformableContact.h"
///btBulletDynamicsCommon.h is the main Bullet include file, contains most common include files.
#include "btBulletDynamicsCommon.h"
#include "BulletSoftBody/btDeformableRigidDynamicsWorld.h"
#include "BulletSoftBody/btSoftBody.h"
#include "BulletSoftBody/btSoftBodyHelpers.h"
#include "BulletSoftBody/btDeformableBodySolver.h"
#include "BulletSoftBody/btSoftBodyRigidBodyCollisionConfiguration.h"
#include "BulletDynamics/Featherstone/btMultiBodyConstraintSolver.h"
#include <stdio.h> //printf debugging
#include "../CommonInterfaces/CommonRigidBodyBase.h"
#include "../Utils/b3ResourcePath.h"
#include "../SoftDemo/BunnyMesh.h"
#include "BulletDynamics/Featherstone/btMultiBodyLinkCollider.h"
#include "BulletDynamics/Featherstone/btMultiBodyJointFeedback.h"
#include "../CommonInterfaces/CommonMultiBodyBase.h"
#include "../Utils/b3ResourcePath.h"
///The DeformableContact demo deformable bodies self-collision
static bool g_floatingBase = true;
static float friction = 1.;
class DeformableContact : public CommonMultiBodyBase
{
btMultiBody* m_multiBody;
btAlignedObjectArray<btMultiBodyJointFeedback*> m_jointFeedbacks;
public:
struct TetraBunny
{
#include "../SoftDemo/bunny.inl"
};
DeformableContact(struct GUIHelperInterface* helper)
: CommonMultiBodyBase(helper)
{
}
virtual ~DeformableContact()
{
}
void initPhysics();
void exitPhysics();
void resetCamera()
{
float dist = 15;
float pitch = -30;
float yaw = 100;
float targetPos[3] = {0, -3, 0};
m_guiHelper->resetCamera(dist, yaw, pitch, targetPos[0], targetPos[1], targetPos[2]);
}
virtual void stepSimulation(float deltaTime);
btMultiBody* createFeatherstoneMultiBody_testMultiDof(class btMultiBodyDynamicsWorld* world, int numLinks, const btVector3& basePosition, const btVector3& baseHalfExtents, const btVector3& linkHalfExtents, bool spherical = false, bool floating = false);
void addColliders_testMultiDof(btMultiBody* pMultiBody, btMultiBodyDynamicsWorld* pWorld, const btVector3& baseHalfExtents, const btVector3& linkHalfExtents);
virtual const btDeformableRigidDynamicsWorld* getDeformableDynamicsWorld() const
{
return (btDeformableRigidDynamicsWorld*)m_dynamicsWorld;
}
virtual btDeformableRigidDynamicsWorld* getDeformableDynamicsWorld()
{
return (btDeformableRigidDynamicsWorld*)m_dynamicsWorld;
}
virtual void renderScene()
{
CommonMultiBodyBase::renderScene();
btDeformableRigidDynamicsWorld* deformableWorld = getDeformableDynamicsWorld();
for (int i = 0; i < deformableWorld->getSoftBodyArray().size(); i++)
{
btSoftBody* psb = (btSoftBody*)deformableWorld->getSoftBodyArray()[i];
{
btSoftBodyHelpers::DrawFrame(psb, deformableWorld->getDebugDrawer());
btSoftBodyHelpers::Draw(psb, deformableWorld->getDebugDrawer(), deformableWorld->getDrawFlags());
}
}
}
};
void DeformableContact::initPhysics()
{
m_guiHelper->setUpAxis(1);
///collision configuration contains default setup for memory, collision setup
m_collisionConfiguration = new btSoftBodyRigidBodyCollisionConfiguration();
///use the default collision dispatcher. For parallel processing you can use a diffent dispatcher (see Extras/BulletMultiThreaded)
m_dispatcher = new btCollisionDispatcher(m_collisionConfiguration);
m_broadphase = new btDbvtBroadphase();
btDeformableBodySolver* deformableBodySolver = new btDeformableBodySolver();
btMultiBodyConstraintSolver* sol;
sol = new btMultiBodyConstraintSolver;
m_solver = sol;
m_dynamicsWorld = new btDeformableRigidDynamicsWorld(m_dispatcher, m_broadphase, sol, m_collisionConfiguration, deformableBodySolver);
deformableBodySolver->setWorld(getDeformableDynamicsWorld());
m_dynamicsWorld->setGravity(btVector3(0, -10, 0));
getDeformableDynamicsWorld()->getWorldInfo().m_gravity.setValue(0, -10, 0);
m_guiHelper->createPhysicsDebugDrawer(m_dynamicsWorld);
{
///create a ground
btCollisionShape* groundShape = new btBoxShape(btVector3(btScalar(150.), btScalar(25.), btScalar(150.)));
m_collisionShapes.push_back(groundShape);
btTransform groundTransform;
groundTransform.setIdentity();
groundTransform.setOrigin(btVector3(0, -40, 0));
groundTransform.setRotation(btQuaternion(btVector3(1, 0, 0), SIMD_PI * 0.0));
//We can also use DemoApplication::localCreateRigidBody, but for clarity it is provided here:
btScalar mass(0.);
//rigidbody is dynamic if and only if mass is non zero, otherwise static
bool isDynamic = (mass != 0.f);
btVector3 localInertia(0, 0, 0);
if (isDynamic)
groundShape->calculateLocalInertia(mass, localInertia);
//using motionstate is recommended, it provides interpolation capabilities, and only synchronizes 'active' objects
btDefaultMotionState* myMotionState = new btDefaultMotionState(groundTransform);
btRigidBody::btRigidBodyConstructionInfo rbInfo(mass, myMotionState, groundShape, localInertia);
btRigidBody* body = new btRigidBody(rbInfo);
body->setFriction(0.5);
//add the ground to the dynamics world
m_dynamicsWorld->addRigidBody(body,1,1+2);
}
{
bool damping = true;
bool gyro = true;
int numLinks = 3;
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);
mbC->setCanSleep(canSleep);
mbC->setHasSelfCollision(selfCollide);
mbC->setUseGyroTerm(gyro);
//
if (!damping)
{
mbC->setLinearDamping(0.f);
mbC->setAngularDamping(0.f);
}
else
{
mbC->setLinearDamping(0.1f);
mbC->setAngularDamping(0.9f);
}
if (numLinks > 0)
{
btScalar q0 = 0.f * SIMD_PI / 180.f;
if (!spherical)
{
mbC->setJointPosMultiDof(0, &q0);
}
else
{
btQuaternion quat0(btVector3(1, 1, 0).normalized(), q0);
quat0.normalize();
mbC->setJointPosMultiDof(0, quat0);
}
}
///
addColliders_testMultiDof(mbC, m_dynamicsWorld, baseHalfExtents, linkHalfExtents);
}
// create a patch of cloth
{
const btScalar s = 6;
btSoftBody* psb = btSoftBodyHelpers::CreatePatch(getDeformableDynamicsWorld()->getWorldInfo(), btVector3(-s, 0, -s),
btVector3(+s, 0, -s),
btVector3(-s, 0, +s),
btVector3(+s, 0, +s),
20,20,
1 + 2 + 4 + 8, true);
psb->getCollisionShape()->setMargin(0.25);
psb->generateBendingConstraints(2);
psb->setTotalMass(.5);
psb->setDampingCoefficient(0.01);
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;
getDeformableDynamicsWorld()->addSoftBody(psb);
}
m_guiHelper->autogenerateGraphicsObjects(m_dynamicsWorld);
}
void DeformableContact::exitPhysics()
{
//cleanup in the reverse order of creation/initialization
//remove the rigidbodies from the dynamics world and delete them
int i;
for (i = m_dynamicsWorld->getNumCollisionObjects() - 1; i >= 0; i--)
{
btCollisionObject* obj = m_dynamicsWorld->getCollisionObjectArray()[i];
btRigidBody* body = btRigidBody::upcast(obj);
if (body && body->getMotionState())
{
delete body->getMotionState();
}
m_dynamicsWorld->removeCollisionObject(obj);
delete obj;
}
//delete collision shapes
for (int j = 0; j < m_collisionShapes.size(); j++)
{
btCollisionShape* shape = m_collisionShapes[j];
delete shape;
}
m_collisionShapes.clear();
delete m_dynamicsWorld;
delete m_solver;
delete m_broadphase;
delete m_dispatcher;
delete m_collisionConfiguration;
}
void DeformableContact::stepSimulation(float deltaTime)
{
// getDeformableDynamicsWorld()->getMultiBodyDynamicsWorld()->stepSimulation(deltaTime);
m_dynamicsWorld->stepSimulation(deltaTime, 4, 1./240.);
}
btMultiBody* DeformableContact::createFeatherstoneMultiBody_testMultiDof(btMultiBodyDynamicsWorld* pWorld, int numLinks, const btVector3& basePosition, const btVector3& baseHalfExtents, const btVector3& linkHalfExtents, bool spherical, bool floating)
{
//init the base
btVector3 baseInertiaDiag(0.f, 0.f, 0.f);
float baseMass = .05f;
if (baseMass)
{
btCollisionShape* pTempBox = new btBoxShape(btVector3(baseHalfExtents[0], baseHalfExtents[1], baseHalfExtents[2]));
pTempBox->calculateLocalInertia(baseMass, baseInertiaDiag);
delete pTempBox;
}
bool canSleep = false;
btMultiBody* pMultiBody = new btMultiBody(numLinks, baseMass, baseInertiaDiag, !floating, canSleep);
btQuaternion baseOriQuat(0.f, 0.f, 0.f, 1.f);
pMultiBody->setBasePos(basePosition);
pMultiBody->setWorldToBaseRot(baseOriQuat);
btVector3 vel(0, 0, 0);
// pMultiBody->setBaseVel(vel);
//init the links
btVector3 hingeJointAxis(1, 0, 0);
float linkMass = .05f;
btVector3 linkInertiaDiag(0.f, 0.f, 0.f);
btCollisionShape* pTempBox = new btBoxShape(btVector3(linkHalfExtents[0], linkHalfExtents[1], linkHalfExtents[2]));
pTempBox->calculateLocalInertia(linkMass, linkInertiaDiag);
delete pTempBox;
//y-axis assumed up
btVector3 parentComToCurrentCom(0, -linkHalfExtents[1] * 2.f, 0); //par body's COM to cur body's COM offset
btVector3 currentPivotToCurrentCom(0, -linkHalfExtents[1], 0); //cur body's COM to cur body's PIV offset
btVector3 parentComToCurrentPivot = parentComToCurrentCom - currentPivotToCurrentCom; //par body's COM to cur body's PIV offset
//////
btScalar q0 = 0.f * SIMD_PI / 180.f;
btQuaternion quat0(btVector3(0, 1, 0).normalized(), q0);
quat0.normalize();
/////
for (int i = 0; i < numLinks; ++i)
{
if (!spherical)
pMultiBody->setupRevolute(i, linkMass, linkInertiaDiag, i - 1, btQuaternion(0.f, 0.f, 0.f, 1.f), hingeJointAxis, parentComToCurrentPivot, currentPivotToCurrentCom, true);
else
//pMultiBody->setupPlanar(i, linkMass, linkInertiaDiag, i - 1, btQuaternion(0.f, 0.f, 0.f, 1.f)/*quat0*/, btVector3(1, 0, 0), parentComToCurrentPivot*2, false);
pMultiBody->setupSpherical(i, linkMass, linkInertiaDiag, i - 1, btQuaternion(0.f, 0.f, 0.f, 1.f), parentComToCurrentPivot, currentPivotToCurrentCom, true);
}
pMultiBody->finalizeMultiDof();
///
pWorld->addMultiBody(pMultiBody);
///
return pMultiBody;
}
void DeformableContact::addColliders_testMultiDof(btMultiBody* pMultiBody, btMultiBodyDynamicsWorld* pWorld, const btVector3& baseHalfExtents, const btVector3& linkHalfExtents)
{
btAlignedObjectArray<btQuaternion> world_to_local;
world_to_local.resize(pMultiBody->getNumLinks() + 1);
btAlignedObjectArray<btVector3> local_origin;
local_origin.resize(pMultiBody->getNumLinks() + 1);
world_to_local[0] = pMultiBody->getWorldToBaseRot();
local_origin[0] = pMultiBody->getBasePos();
{
// float pos[4]={local_origin[0].x(),local_origin[0].y(),local_origin[0].z(),1};
btScalar quat[4] = {-world_to_local[0].x(), -world_to_local[0].y(), -world_to_local[0].z(), world_to_local[0].w()};
if (1)
{
btCollisionShape* box = new btBoxShape(baseHalfExtents);
btMultiBodyLinkCollider* col = new btMultiBodyLinkCollider(pMultiBody, -1);
col->setCollisionShape(box);
btTransform tr;
tr.setIdentity();
tr.setOrigin(local_origin[0]);
tr.setRotation(btQuaternion(quat[0], quat[1], quat[2], quat[3]));
col->setWorldTransform(tr);
pWorld->addCollisionObject(col, 2, 1 + 2);
col->setFriction(friction);
pMultiBody->setBaseCollider(col);
}
}
for (int i = 0; i < pMultiBody->getNumLinks(); ++i)
{
const int parent = pMultiBody->getParent(i);
world_to_local[i + 1] = pMultiBody->getParentToLocalRot(i) * world_to_local[parent + 1];
local_origin[i + 1] = local_origin[parent + 1] + (quatRotate(world_to_local[i + 1].inverse(), pMultiBody->getRVector(i)));
}
for (int i = 0; i < pMultiBody->getNumLinks(); ++i)
{
btVector3 posr = local_origin[i + 1];
// float pos[4]={posr.x(),posr.y(),posr.z(),1};
btScalar quat[4] = {-world_to_local[i + 1].x(), -world_to_local[i + 1].y(), -world_to_local[i + 1].z(), world_to_local[i + 1].w()};
btCollisionShape* box = new btBoxShape(linkHalfExtents);
btMultiBodyLinkCollider* col = new btMultiBodyLinkCollider(pMultiBody, i);
col->setCollisionShape(box);
btTransform tr;
tr.setIdentity();
tr.setOrigin(posr);
tr.setRotation(btQuaternion(quat[0], quat[1], quat[2], quat[3]));
col->setWorldTransform(tr);
col->setFriction(friction);
pWorld->addCollisionObject(col, 2, 1 + 2);
pMultiBody->getLink(i).m_collider = col;
}
}
class CommonExampleInterface* DeformableContactCreateFunc(struct CommonExampleOptions& options)
{
return new DeformableContact(options.m_guiHelper);
}

20
examples/DeformableContact/DeformableContact.h Normal file
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@ -0,0 +1,20 @@
/*
Bullet Continuous Collision Detection and Physics Library
Copyright (c) 2003-2006 Erwin Coumans http://continuousphysics.com/Bullet/
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.
*/
#ifndef _DEFORMABLE_CONTACT_H
#define _DEFORMABLE_CONTACT_H
class CommonExampleInterface* DeformableContactCreateFunc(struct CommonExampleOptions& options);
#endif //_DEFORMABLE_CONTACT_H

90
examples/DeformableDemo/DeformableDemo.cpp
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@ -35,6 +35,7 @@ subject to the following restrictions:
#include "BulletSoftBody/btSoftBodyHelpers.h"
#include "BulletSoftBody/btDeformableBodySolver.h"
#include "BulletSoftBody/btSoftBodyRigidBodyCollisionConfiguration.h"
#include "BulletDynamics/Featherstone/btMultiBodyConstraintSolver.h"
#include <stdio.h> //printf debugging
#include "../CommonInterfaces/CommonRigidBodyBase.h"
@ -59,17 +60,23 @@ public:
void resetCamera()
{
float dist = 15;
float dist = 20;
float pitch = -45;
float yaw = 100;
float targetPos[3] = {0, -5, 0};
float targetPos[3] = {0, -3, 0};
m_guiHelper->resetCamera(dist, yaw, pitch, targetPos[0], targetPos[1], targetPos[2]);
}
void stepSimulation(float deltaTime)
{
//use a smaller internal timestep, there are stability issues
float internalTimeStep = 1. / 240.f;
m_dynamicsWorld->stepSimulation(deltaTime, 4, internalTimeStep);
}
void Ctor_RbUpStack(int count)
{
float mass = 1;
float mass = 0.2;
btCompoundShape* cylinderCompound = new btCompoundShape;
btCollisionShape* cylinderShape = new btCylinderShapeX(btVector3(2, .5, .5));
@ -84,18 +91,30 @@ public:
btCollisionShape* shape[] = {
new btBoxShape(btVector3(1, 1, 1)),
cylinderCompound,
new btSphereShape(0.75)
// new btSphereShape(0.75),
// cylinderCompound
};
static const int nshapes = sizeof(shape) / sizeof(shape[0]);
for (int i = 0; i < count; ++i)
{
btTransform startTransform;
startTransform.setIdentity();
startTransform.setOrigin(btVector3(0, 3 + 3 * i, 0));
createRigidBody(mass, startTransform, shape[i % nshapes]);
}
// static const int nshapes = sizeof(shape) / sizeof(shape[0]);
// for (int i = 0; i < count; ++i)
// {
// btTransform startTransform;
// startTransform.setIdentity();
// startTransform.setOrigin(btVector3(0, 2+ 2 * i, 0));
// startTransform.setRotation(btQuaternion(btVector3(1, 0, 0), SIMD_PI * 0.));
// createRigidBody(mass, startTransform, shape[i % nshapes]);
// }
btTransform startTransform;
startTransform.setIdentity();
startTransform.setOrigin(btVector3(1, 2, 1));
createRigidBody(mass, startTransform, shape[0]);
startTransform.setOrigin(btVector3(1, 2, -1));
createRigidBody(mass, startTransform, shape[0]);
startTransform.setOrigin(btVector3(-1, 2, 1));
createRigidBody(mass, startTransform, shape[0]);
startTransform.setOrigin(btVector3(-1, 2, -1));
createRigidBody(mass, startTransform, shape[0]);
startTransform.setOrigin(btVector3(0, 4, 0));
createRigidBody(mass, startTransform, shape[0]);
}
virtual const btDeformableRigidDynamicsWorld* getDeformableDynamicsWorld() const
@ -143,14 +162,16 @@ void DeformableDemo::initPhysics()
btDeformableBodySolver* deformableBodySolver = new btDeformableBodySolver();
///the default constraint solver. For parallel processing you can use a different solver (see Extras/BulletMultiThreaded)
btSequentialImpulseConstraintSolver* sol = new btSequentialImpulseConstraintSolver;
btMultiBodyConstraintSolver* sol = new btMultiBodyConstraintSolver();
m_solver = sol;
m_dynamicsWorld = new btDeformableRigidDynamicsWorld(m_dispatcher, m_broadphase, m_solver, m_collisionConfiguration, deformableBodySolver);
m_dynamicsWorld = new btDeformableRigidDynamicsWorld(m_dispatcher, m_broadphase, sol, m_collisionConfiguration, deformableBodySolver);
deformableBodySolver->setWorld(getDeformableDynamicsWorld());
// m_dynamicsWorld->getSolverInfo().m_singleAxisDeformableThreshold = 0.f;//faster but lower quality
m_dynamicsWorld->setGravity(btVector3(0, -10, 0));
getDeformableDynamicsWorld()->getSoftDynamicsWorld()->getWorldInfo().m_gravity.setValue(0, -10, 0);
getDeformableDynamicsWorld()->getWorldInfo().m_gravity.setValue(0, -10, 0);
// getDeformableDynamicsWorld()->before_solver_callbacks.push_back(dynamics);
m_guiHelper->createPhysicsDebugDrawer(m_dynamicsWorld);
{
@ -161,8 +182,8 @@ void DeformableDemo::initPhysics()
btTransform groundTransform;
groundTransform.setIdentity();
groundTransform.setOrigin(btVector3(0, -50, 0));
groundTransform.setRotation(btQuaternion(btVector3(1, 0, 0), SIMD_PI * 0.0));
groundTransform.setOrigin(btVector3(0, -30, 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.);
@ -177,7 +198,7 @@ void DeformableDemo::initPhysics()
btDefaultMotionState* myMotionState = new btDefaultMotionState(groundTransform);
btRigidBody::btRigidBodyConstructionInfo rbInfo(mass, myMotionState, groundShape, localInertia);
btRigidBody* body = new btRigidBody(rbInfo);
body->setFriction(.5);
body->setFriction(1);
//add the ground to the dynamics world
m_dynamicsWorld->addRigidBody(body);
@ -185,24 +206,37 @@ void DeformableDemo::initPhysics()
// create a piece of cloth
{
bool onGround = true;
const btScalar s = 4;
btSoftBody* psb = btSoftBodyHelpers::CreatePatch(getDeformableDynamicsWorld()->getSoftDynamicsWorld()->getWorldInfo(), btVector3(-s, 0, -s),
btSoftBody* psb = btSoftBodyHelpers::CreatePatch(getDeformableDynamicsWorld()->getWorldInfo(), btVector3(-s, 0, -s),
btVector3(+s, 0, -s),
btVector3(-s, 0, +s),
btVector3(+s, 0, +s),
// 3, 3,
20,20,
// 3,3,
20,20,
1 + 2 + 4 + 8, true);
// 0, true);
// 0, true);
if (onGround)
psb = btSoftBodyHelpers::CreatePatch(getDeformableDynamicsWorld()->getWorldInfo(), btVector3(-s, 0, -s),
btVector3(+s, 0, -s),
btVector3(-s, 0, +s),
btVector3(+s, 0, +s),
20,20,
0, true);
psb->getCollisionShape()->setMargin(0.25);
psb->getCollisionShape()->setMargin(0.1);
psb->generateBendingConstraints(2);
psb->setTotalMass(2);
psb->setDampingCoefficient(0.02);
psb->setTotalMass(10);
psb->setSpringStiffness(10);
psb->setDampingCoefficient(0.01);
psb->m_cfg.kKHR = 1; // collision hardness with kinematic objects
psb->m_cfg.kCHR = 1; // collision hardness with rigid body
psb->m_cfg.kDF = 1;
getDeformableDynamicsWorld()->addSoftBody(psb);
// add a few rigid bodies
Ctor_RbUpStack(10);
Ctor_RbUpStack(1);
}
m_guiHelper->autogenerateGraphicsObjects(m_dynamicsWorld);
}

8
examples/ExampleBrowser/ExampleEntries.cpp
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@ -48,6 +48,9 @@
#include "../DynamicControlDemo/MotorDemo.h"
#include "../RollingFrictionDemo/RollingFrictionDemo.h"
#include "../DeformableDemo/DeformableDemo.h"
#include "../Pinch/Pinch.h"
#include "../DeformableContact/DeformableContact.h"
#include "../VolumetricDeformable/VolumetricDeformable.h"
#include "../SharedMemory/PhysicsServerExampleBullet2.h"
#include "../SharedMemory/PhysicsServerExample.h"
#include "../SharedMemory/PhysicsClientExample.h"
@ -119,7 +122,10 @@ static ExampleEntry gDefaultExamples[] =
ExampleEntry(1, "Rolling Friction", "Damping is often not good enough to keep rounded objects from rolling down a sloped surface. Instead, you can set the rolling friction of a rigid body. Generally it is best to leave the rolling friction to zero, to avoid artifacts.", RollingFrictionCreateFunc),
ExampleEntry(0, "Deformable", "Deformable test", DeformableCreateFunc),
ExampleEntry(0, "Deformable-RigidBody Contact", "Deformable test", DeformableCreateFunc),
ExampleEntry(0, "Grasp Deformable Cube", "Grasping test", PinchCreateFunc),
ExampleEntry(0, "Volumetric Deformable Objects", "Volumetric Deformable test", VolumetricDeformableCreateFunc),
ExampleEntry(0, "Deformable-MultiBody Contact", "MultiBody and Deformable contact", DeformableContactCreateFunc),
ExampleEntry(1, "Constraints", "Show the use of the various constraints in Bullet. Press the L key to visualize the constraint limits. Press the C key to visualize the constraint frames.",
AllConstraintCreateFunc),

297
examples/Pinch/Pinch.cpp Normal file
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@ -0,0 +1,297 @@
/*
Bullet Continuous Collision Detection and Physics Library
Copyright (c) 2003-2006 Erwin Coumans http://continuousphysics.com/Bullet/
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.
*/
///create 125 (5x5x5) dynamic object
#define ARRAY_SIZE_X 5
#define ARRAY_SIZE_Y 5
#define ARRAY_SIZE_Z 5
//maximum number of objects (and allow user to shoot additional boxes)
#define MAX_PROXIES (ARRAY_SIZE_X * ARRAY_SIZE_Y * ARRAY_SIZE_Z + 1024)
///scaling of the objects (0.1 = 20 centimeter boxes )
#define SCALING 1.
#define START_POS_X -5
#define START_POS_Y -5
#define START_POS_Z -3
#include "Pinch.h"
///btBulletDynamicsCommon.h is the main Bullet include file, contains most common include files.
#include "btBulletDynamicsCommon.h"
#include "BulletSoftBody/btDeformableRigidDynamicsWorld.h"
#include "BulletSoftBody/btSoftBody.h"
#include "BulletSoftBody/btSoftBodyHelpers.h"
#include "BulletSoftBody/btDeformableBodySolver.h"
#include "BulletSoftBody/btSoftBodyRigidBodyCollisionConfiguration.h"
#include "BulletDynamics/Featherstone/btMultiBodyConstraintSolver.h"
#include <stdio.h> //printf debugging
#include "../CommonInterfaces/CommonRigidBodyBase.h"
#include "../Utils/b3ResourcePath.h"
///The Pinch shows the use of rolling friction.
///Spheres will come to a rest on a sloped plane using a constraint. Damping cannot achieve the same.
///Generally it is best to leave the rolling friction coefficient zero (or close to zero).
struct TetraCube
{
#include "../SoftDemo/cube.inl"
};
struct TetraBunny
{
#include "../SoftDemo/bunny.inl"
};
class Pinch : public CommonRigidBodyBase
{
public:
Pinch(struct GUIHelperInterface* helper)
: CommonRigidBodyBase(helper)
{
}
virtual ~Pinch()
{
}
void initPhysics();
void exitPhysics();
void resetCamera()
{
float dist = 25;
float pitch = -45;
float yaw = 100;
float targetPos[3] = {0, -3, 0};
m_guiHelper->resetCamera(dist, yaw, pitch, targetPos[0], targetPos[1], targetPos[2]);
}
void stepSimulation(float deltaTime)
{
//use a smaller internal timestep, there are stability issues
float internalTimeStep = 1. / 240.f;
m_dynamicsWorld->stepSimulation(deltaTime, 4, internalTimeStep);
}
void createGrip()
{
int count = 2;
float mass = 2;
btCollisionShape* shape[] = {
new btBoxShape(btVector3(3, 3, 0.5)),
};
static const int nshapes = sizeof(shape) / sizeof(shape[0]);
for (int i = 0; i < count; ++i)
{
btTransform startTransform;
startTransform.setIdentity();
startTransform.setOrigin(btVector3(10, 0, 0));
startTransform.setRotation(btQuaternion(btVector3(1, 0, 0), SIMD_PI * 0.));
createRigidBody(mass, startTransform, shape[i % nshapes]);
}
}
virtual const btDeformableRigidDynamicsWorld* getDeformableDynamicsWorld() const
{
return (btDeformableRigidDynamicsWorld*)m_dynamicsWorld;
}
virtual btDeformableRigidDynamicsWorld* getDeformableDynamicsWorld()
{
return (btDeformableRigidDynamicsWorld*)m_dynamicsWorld;
}
virtual void renderScene()
{
CommonRigidBodyBase::renderScene();
btDeformableRigidDynamicsWorld* deformableWorld = getDeformableDynamicsWorld();
for (int i = 0; i < deformableWorld->getSoftBodyArray().size(); i++)
{
btSoftBody* psb = (btSoftBody*)deformableWorld->getSoftBodyArray()[i];
{
btSoftBodyHelpers::DrawFrame(psb, deformableWorld->getDebugDrawer());
btSoftBodyHelpers::Draw(psb, deformableWorld->getDebugDrawer(), deformableWorld->getDrawFlags());
}
}
}
};
void dynamics(btScalar time, btDeformableRigidDynamicsWorld* world)
{
btAlignedObjectArray<btRigidBody*>& rbs = world->getNonStaticRigidBodies();
if (rbs.size()<2)
return;
btRigidBody* rb0 = rbs[0];
btScalar pressTime = 0.9;
btTransform rbTransform;
rbTransform.setIdentity();
btVector3 translation = btVector3(0.5,3,4);
btVector3 velocity = btVector3(0,5,0);
if (time < pressTime)
{
velocity = btVector3(0,0,-2);
translation += velocity * time;
}
else
translation += btVector3(0,0,-2) * pressTime + (time-pressTime)*velocity;
rbTransform.setOrigin(translation);
rbTransform.setRotation(btQuaternion(btVector3(1, 0, 0), SIMD_PI * 0));
rb0->setCenterOfMassTransform(rbTransform);
rb0->setAngularVelocity(btVector3(0,0,0));
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;
}
else
translation += btVector3(0,0,2) * pressTime + (time-pressTime)*velocity;
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);
}
void Pinch::initPhysics()
{
m_guiHelper->setUpAxis(1);
m_collisionConfiguration = new btSoftBodyRigidBodyCollisionConfiguration();
m_dispatcher = new btCollisionDispatcher(m_collisionConfiguration);
m_broadphase = new btDbvtBroadphase();
btDeformableBodySolver* deformableBodySolver = new btDeformableBodySolver();
btMultiBodyConstraintSolver* sol = new btMultiBodyConstraintSolver();
m_solver = sol;
m_dynamicsWorld = new btDeformableRigidDynamicsWorld(m_dispatcher, m_broadphase, sol, m_collisionConfiguration, deformableBodySolver);
deformableBodySolver->setWorld(getDeformableDynamicsWorld());
// m_dynamicsWorld->getSolverInfo().m_singleAxisDeformableThreshold = 0.f;//faster but lower quality
m_dynamicsWorld->setGravity(btVector3(0, -10, 0));
getDeformableDynamicsWorld()->getWorldInfo().m_gravity.setValue(0, -10, 0);
getDeformableDynamicsWorld()->before_solver_callbacks.push_back(dynamics);
m_guiHelper->createPhysicsDebugDrawer(m_dynamicsWorld);
//create a ground
{
btCollisionShape* groundShape = new btBoxShape(btVector3(btScalar(150.), btScalar(25.), btScalar(150.)));
m_collisionShapes.push_back(groundShape);
btTransform groundTransform;
groundTransform.setIdentity();
groundTransform.setOrigin(btVector3(0, -25, 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.);
//rigidbody is dynamic if and only if mass is non zero, otherwise static
bool isDynamic = (mass != 0.f);
btVector3 localInertia(0, 0, 0);
if (isDynamic)
groundShape->calculateLocalInertia(mass, localInertia);
//using motionstate is recommended, it provides interpolation capabilities, and only synchronizes 'active' objects
btDefaultMotionState* myMotionState = new btDefaultMotionState(groundTransform);
btRigidBody::btRigidBodyConstructionInfo rbInfo(mass, myMotionState, groundShape, localInertia);
btRigidBody* body = new btRigidBody(rbInfo);
body->setFriction(0.5);
//add the ground to the dynamics world
m_dynamicsWorld->addRigidBody(body);
}
// create a soft block
{
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->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;
// add a grippers
createGrip();
}
m_guiHelper->autogenerateGraphicsObjects(m_dynamicsWorld);
}
void Pinch::exitPhysics()
{
//cleanup in the reverse order of creation/initialization
//remove the rigidbodies from the dynamics world and delete them
int i;
for (i = m_dynamicsWorld->getNumCollisionObjects() - 1; i >= 0; i--)
{
btCollisionObject* obj = m_dynamicsWorld->getCollisionObjectArray()[i];
btRigidBody* body = btRigidBody::upcast(obj);
if (body && body->getMotionState())
{
delete body->getMotionState();
}
m_dynamicsWorld->removeCollisionObject(obj);
delete obj;
}
//delete collision shapes
for (int j = 0; j < m_collisionShapes.size(); j++)
{
btCollisionShape* shape = m_collisionShapes[j];
delete shape;
}
m_collisionShapes.clear();
delete m_dynamicsWorld;
delete m_solver;
delete m_broadphase;
delete m_dispatcher;
delete m_collisionConfiguration;
}
class CommonExampleInterface* PinchCreateFunc(struct CommonExampleOptions& options)
{
return new Pinch(options.m_guiHelper);
}

20
examples/Pinch/Pinch.h Normal file
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@ -0,0 +1,20 @@
/*
Bullet Continuous Collision Detection and Physics Library
Copyright (c) 2003-2006 Erwin Coumans http://continuousphysics.com/Bullet/
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.
*/
#ifndef _PINCH_H
#define _PINCH_H
class CommonExampleInterface* PinchCreateFunc(struct CommonExampleOptions& options);
#endif //_PINCH_H

294
examples/VolumetricDeformable/VolumetricDeformable.cpp Normal file
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@ -0,0 +1,294 @@
/*
Bullet Continuous Collision Detection and Physics Library
Copyright (c) 2003-2006 Erwin Coumans http://continuousphysics.com/Bullet/
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.
*/
///create 125 (5x5x5) dynamic object
#define ARRAY_SIZE_X 5
#define ARRAY_SIZE_Y 5
#define ARRAY_SIZE_Z 5
//maximum number of objects (and allow user to shoot additional boxes)
#define MAX_PROXIES (ARRAY_SIZE_X * ARRAY_SIZE_Y * ARRAY_SIZE_Z + 1024)
///scaling of the objects (0.1 = 20 centimeter boxes )
#define SCALING 1.
#define START_POS_X -5
#define START_POS_Y -5
#define START_POS_Z -3
#include "VolumetricDeformable.h"
///btBulletDynamicsCommon.h is the main Bullet include file, contains most common include files.
#include "btBulletDynamicsCommon.h"
#include "BulletSoftBody/btDeformableRigidDynamicsWorld.h"
#include "BulletSoftBody/btSoftBody.h"
#include "BulletSoftBody/btSoftBodyHelpers.h"
#include "BulletSoftBody/btDeformableBodySolver.h"
#include "BulletSoftBody/btSoftBodyRigidBodyCollisionConfiguration.h"
#include "BulletDynamics/Featherstone/btMultiBodyConstraintSolver.h"
#include <stdio.h> //printf debugging
#include "../CommonInterfaces/CommonRigidBodyBase.h"
#include "../Utils/b3ResourcePath.h"
///The VolumetricDeformable shows the use of rolling friction.
///Spheres will come to a rest on a sloped plane using a constraint. Damping cannot achieve the same.
///Generally it is best to leave the rolling friction coefficient zero (or close to zero).
struct TetraCube
{
#include "../SoftDemo/cube.inl"
};
class VolumetricDeformable : public CommonRigidBodyBase
{
public:
VolumetricDeformable(struct GUIHelperInterface* helper)
: CommonRigidBodyBase(helper)
{
}
virtual ~VolumetricDeformable()
{
}
void initPhysics();
void exitPhysics();
void resetCamera()
{
float dist = 20;
float pitch = -45;
float yaw = 100;
float targetPos[3] = {0, 3, 0};
m_guiHelper->resetCamera(dist, yaw, pitch, targetPos[0], targetPos[1], targetPos[2]);
}
void stepSimulation(float deltaTime)
{
//use a smaller internal timestep, there are stability issues
float internalTimeStep = 1. / 240.f;
m_dynamicsWorld->stepSimulation(deltaTime, 4, internalTimeStep);
}
void createStaticBox(const btVector3& halfEdge, const btVector3& translation)
{
btCollisionShape* box = new btBoxShape(halfEdge);
m_collisionShapes.push_back(box);
btTransform Transform;
Transform.setIdentity();
Transform.setOrigin(translation);
Transform.setRotation(btQuaternion(btVector3(1, 0, 0), SIMD_PI * 0.0));
//We can also use DemoApplication::localCreateRigidBody, but for clarity it is provided here:
btScalar mass(0.);
//rigidbody is dynamic if and only if mass is non zero, otherwise static
bool isDynamic = (mass != 0.f);
btVector3 localInertia(0, 0, 0);
if (isDynamic)
box->calculateLocalInertia(mass, localInertia);
//using motionstate is recommended, it provides interpolation capabilities, and only synchronizes 'active' objects
btDefaultMotionState* myMotionState = new btDefaultMotionState(Transform);
btRigidBody::btRigidBodyConstructionInfo rbInfo(mass, myMotionState, box, localInertia);
btRigidBody* body = new btRigidBody(rbInfo);
body->setFriction(0.5);
//add the ground to the dynamics world
m_dynamicsWorld->addRigidBody(body);
}
void Ctor_RbUpStack(int count)
{
float mass = 0.02;
btCompoundShape* cylinderCompound = new btCompoundShape;
btCollisionShape* cylinderShape = new btCylinderShapeX(btVector3(2, .5, .5));
btCollisionShape* boxShape = new btBoxShape(btVector3(2, .5, .5));
btTransform localTransform;
localTransform.setIdentity();
cylinderCompound->addChildShape(localTransform, boxShape);
btQuaternion orn(SIMD_HALF_PI, 0, 0);
localTransform.setRotation(orn);
// localTransform.setOrigin(btVector3(1,1,1));
cylinderCompound->addChildShape(localTransform, cylinderShape);
btCollisionShape* shape[] = {
new btBoxShape(btVector3(1, 1, 1)),
};
static const int nshapes = sizeof(shape) / sizeof(shape[0]);
for (int i = 0; i < count; ++i)
{
btTransform startTransform;
startTransform.setIdentity();
startTransform.setOrigin(btVector3(i, 10 + 2 * i, i-1));
createRigidBody(mass, startTransform, shape[i % nshapes]);
}
}
virtual const btDeformableRigidDynamicsWorld* getDeformableDynamicsWorld() const
{
///just make it a btSoftRigidDynamicsWorld please
///or we will add type checking
return (btDeformableRigidDynamicsWorld*)m_dynamicsWorld;
}
virtual btDeformableRigidDynamicsWorld* getDeformableDynamicsWorld()
{
///just make it a btSoftRigidDynamicsWorld please
///or we will add type checking
return (btDeformableRigidDynamicsWorld*)m_dynamicsWorld;
}
virtual void renderScene()
{
CommonRigidBodyBase::renderScene();
btDeformableRigidDynamicsWorld* deformableWorld = getDeformableDynamicsWorld();
for (int i = 0; i < deformableWorld->getSoftBodyArray().size(); i++)
{
btSoftBody* psb = (btSoftBody*)deformableWorld->getSoftBodyArray()[i];
//if (softWorld->getDebugDrawer() && !(softWorld->getDebugDrawer()->getDebugMode() & (btIDebugDraw::DBG_DrawWireframe)))
{
btSoftBodyHelpers::DrawFrame(psb, deformableWorld->getDebugDrawer());
btSoftBodyHelpers::Draw(psb, deformableWorld->getDebugDrawer(), deformableWorld->getDrawFlags());
}
}
}
};
void VolumetricDeformable::initPhysics()
{
m_guiHelper->setUpAxis(1);
///collision configuration contains default setup for memory, collision setup
m_collisionConfiguration = new btSoftBodyRigidBodyCollisionConfiguration();
///use the default collision dispatcher. For parallel processing you can use a diffent dispatcher (see Extras/BulletMultiThreaded)
m_dispatcher = new btCollisionDispatcher(m_collisionConfiguration);
m_broadphase = new btDbvtBroadphase();
btDeformableBodySolver* deformableBodySolver = new btDeformableBodySolver();
///the default constraint solver. For parallel processing you can use a different solver (see Extras/BulletMultiThreaded)
btMultiBodyConstraintSolver* sol = new btMultiBodyConstraintSolver();
m_solver = sol;
m_dynamicsWorld = new btDeformableRigidDynamicsWorld(m_dispatcher, m_broadphase, sol, m_collisionConfiguration, deformableBodySolver);
deformableBodySolver->setWorld(getDeformableDynamicsWorld());
// m_dynamicsWorld->getSolverInfo().m_singleAxisDeformableThreshold = 0.f;//faster but lower quality
m_dynamicsWorld->setGravity(btVector3(0, -10, 0));
getDeformableDynamicsWorld()->getWorldInfo().m_gravity.setValue(0, -10, 0);
m_guiHelper->createPhysicsDebugDrawer(m_dynamicsWorld);
{
///create a ground
btCollisionShape* groundShape = new btBoxShape(btVector3(btScalar(150.), btScalar(50.), btScalar(150.)));
m_collisionShapes.push_back(groundShape);
btTransform groundTransform;
groundTransform.setIdentity();
groundTransform.setOrigin(btVector3(0, -50, 0));
groundTransform.setRotation(btQuaternion(btVector3(1, 0, 0), SIMD_PI * 0.0));
//We can also use DemoApplication::localCreateRigidBody, but for clarity it is provided here:
btScalar mass(0.);
//rigidbody is dynamic if and only if mass is non zero, otherwise static
bool isDynamic = (mass != 0.f);
btVector3 localInertia(0, 0, 0);
if (isDynamic)
groundShape->calculateLocalInertia(mass, localInertia);
//using motionstate is recommended, it provides interpolation capabilities, and only synchronizes 'active' objects
btDefaultMotionState* myMotionState = new btDefaultMotionState(groundTransform);
btRigidBody::btRigidBodyConstructionInfo rbInfo(mass, myMotionState, groundShape, localInertia);
btRigidBody* body = new btRigidBody(rbInfo);
body->setFriction(0.5);
//add the ground to the dynamics world
m_dynamicsWorld->addRigidBody(body);
}
createStaticBox(btVector3(1, 5, 5), btVector3(-5,0,0));
createStaticBox(btVector3(1, 5, 5), btVector3(5,0,0));
createStaticBox(btVector3(5, 5, 1), btVector3(0,0,5));
createStaticBox(btVector3(5, 5, 1), btVector3(0,0,-5));
// create volumetric soft body
{
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, 5, 0));
// psb->setVolumeMass(10);
psb->getCollisionShape()->setMargin(0.25);
// psb->generateBendingConstraints(2);
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
psb->m_cfg.kDF = 0.5;
}
// add a few rigid bodies
Ctor_RbUpStack(4);
m_guiHelper->autogenerateGraphicsObjects(m_dynamicsWorld);
}
void VolumetricDeformable::exitPhysics()
{
//cleanup in the reverse order of creation/initialization
//remove the rigidbodies from the dynamics world and delete them
int i;
for (i = m_dynamicsWorld->getNumCollisionObjects() - 1; i >= 0; i--)
{
btCollisionObject* obj = m_dynamicsWorld->getCollisionObjectArray()[i];
btRigidBody* body = btRigidBody::upcast(obj);
if (body && body->getMotionState())
{
delete body->getMotionState();
}
m_dynamicsWorld->removeCollisionObject(obj);
delete obj;
}
//delete collision shapes
for (int j = 0; j < m_collisionShapes.size(); j++)
{
btCollisionShape* shape = m_collisionShapes[j];
delete shape;
}
m_collisionShapes.clear();
delete m_dynamicsWorld;
delete m_solver;
delete m_broadphase;
delete m_dispatcher;
delete m_collisionConfiguration;
}
class CommonExampleInterface* VolumetricDeformableCreateFunc(struct CommonExampleOptions& options)
{
return new VolumetricDeformable(options.m_guiHelper);
}

20
examples/VolumetricDeformable/VolumetricDeformable.h Normal file
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@ -0,0 +1,20 @@
/*
Bullet Continuous Collision Detection and Physics Library
Copyright (c) 2003-2006 Erwin Coumans http://continuousphysics.com/Bullet/
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.
*/
#ifndef _VOLUMETRIC_DEFORMABLE_H
#define _VOLUMETRIC_DEFORMABLE_H
class CommonExampleInterface* VolumetricDeformableCreateFunc(struct CommonExampleOptions& options);
#endif //_VOLUMETRIC_DEFORMABLE__H

47
src/BulletSoftBody/btBackwardEulerObjective.cpp
View File

@ -77,6 +77,51 @@ void btBackwardEulerObjective::updateVelocity(const TVStack& dv)
}
}
void btBackwardEulerObjective::applyForce(TVStack& force, bool setZero)
{
size_t counter = 0;
for (int i = 0; i < m_softBodies.size(); ++i)
{
btSoftBody* psb = m_softBodies[i];
for (int j = 0; j < psb->m_nodes.size(); ++j)
{
btScalar one_over_mass = (psb->m_nodes[j].m_im == 0) ? 0 : psb->m_nodes[j].m_im;
psb->m_nodes[j].m_v += one_over_mass * force[counter++];
}
}
if (setZero)
{
for (int i = 0; i < force.size(); ++i)
force[i].setZero();
}
}
void btBackwardEulerObjective::computeResidual(btScalar dt, TVStack &residual) const
{
// add implicit force
for (int i = 0; i < m_lf.size(); ++i)
{
m_lf[i]->addScaledImplicitForce(dt, residual);
}
}
btScalar btBackwardEulerObjective::computeNorm(const TVStack& residual) const
{
btScalar norm_squared = 0;
for (int i = 0; i < residual.size(); ++i)
{
norm_squared += residual[i].length2();
}
return std::sqrt(norm_squared+SIMD_EPSILON);
}
void btBackwardEulerObjective::applyExplicitForce(TVStack& force)
{
for (int i = 0; i < m_lf.size(); ++i)
m_lf[i]->addScaledExplicitForce(m_dt, force);
applyForce(force, true);
}
void btBackwardEulerObjective::initialGuess(TVStack& dv, const TVStack& residual)
{
size_t counter = 0;
@ -85,7 +130,7 @@ void btBackwardEulerObjective::initialGuess(TVStack& dv, const TVStack& residual
btSoftBody* psb = m_softBodies[i];
for (int j = 0; j < psb->m_nodes.size(); ++j)
{
dv[counter] = psb->m_nodes[j].m_im * residual[counter] * 1;
dv[counter] = psb->m_nodes[j].m_im * residual[counter];
++counter;
}
}

118
src/BulletSoftBody/btBackwardEulerObjective.h
View File

@ -12,66 +12,10 @@
#include "btLagrangianForce.h"
#include "btMassSpring.h"
#include "btContactProjection.h"
#include "btPreconditioner.h"
#include "btDeformableRigidDynamicsWorld.h"
class btDeformableRigidDynamicsWorld;
class Preconditioner
{
public:
using TVStack = btAlignedObjectArray<btVector3>;
virtual void operator()(const TVStack& x, TVStack& b) = 0;
virtual void reinitialize(bool nodeUpdated) = 0;
};
class DefaultPreconditioner : public Preconditioner
{
public:
virtual void operator()(const TVStack& x, TVStack& b)
{
btAssert(b.size() == x.size());
for (int i = 0; i < b.size(); ++i)
b[i] = x[i];
}
virtual void reinitialize(bool nodeUpdated)
{
}
};
class MassPreconditioner : public Preconditioner
{
btAlignedObjectArray<btScalar> m_inv_mass;
const btAlignedObjectArray<btSoftBody *>& m_softBodies;
public:
MassPreconditioner(const btAlignedObjectArray<btSoftBody *>& softBodies)
: m_softBodies(softBodies)
{
}
virtual void reinitialize(bool nodeUpdated)
{
if (nodeUpdated)
{
m_inv_mass.clear();
for (int i = 0; i < m_softBodies.size(); ++i)
{
btSoftBody* psb = m_softBodies[i];
for (int j = 0; j < psb->m_nodes.size(); ++j)
m_inv_mass.push_back(psb->m_nodes[j].m_im);
}
}
}
virtual void operator()(const TVStack& x, TVStack& b)
{
btAssert(b.size() == x.size());
btAssert(m_inv_mass.size() == x.size());
for (int i = 0; i < b.size(); ++i)
b[i] = x[i] * m_inv_mass[i];
}
};
class btBackwardEulerObjective
{
public:
@ -91,74 +35,60 @@ public:
void initialize(){}
void computeResidual(btScalar dt, TVStack& residual) const
{
// add implicit force
for (int i = 0; i < m_lf.size(); ++i)
{
m_lf[i]->addScaledImplicitForce(dt, residual);
}
}
// compute the rhs for CG solve, i.e, add the dt scaled implicit force to residual
void computeResidual(btScalar dt, TVStack& residual) const;
void applyExplicitForce(TVStack& force)
{
for (int i = 0; i < m_lf.size(); ++i)
m_lf[i]->addScaledExplicitForce(m_dt, force);
size_t counter = 0;
for (int i = 0; i < m_softBodies.size(); ++i)
{
btSoftBody* psb = m_softBodies[i];
for (int j = 0; j < psb->m_nodes.size(); ++j)
{
btScalar one_over_mass = (psb->m_nodes[j].m_im == 0) ? 0 : psb->m_nodes[j].m_im;
psb->m_nodes[j].m_v += one_over_mass * force[counter];
force[counter].setZero();
counter++;
}
}
}
// add explicit force to the velocity
void applyExplicitForce(TVStack& force);
btScalar computeNorm(const TVStack& residual) const
{
btScalar norm_squared = 0;
for (int i = 0; i < residual.size(); ++i)
{
norm_squared += residual[i].length2();
}
return std::sqrt(norm_squared+SIMD_EPSILON);
}
// apply force to velocity and optionally reset the force to zero
void applyForce(TVStack& force, bool setZero);
// compute the norm of the residual
btScalar computeNorm(const TVStack& residual) const;
// compute one step of the solve (there is only one solve if the system is linear)
void computeStep(TVStack& dv, const TVStack& residual, const btScalar& dt);
// perform A*x = b
void multiply(const TVStack& x, TVStack& b) const;
// update the constraints treated as projections
void updateProjection(const TVStack& dv)
{
projection.update(dv, m_backupVelocity);
}
// set initial guess for CG solve
void initialGuess(TVStack& dv, const TVStack& residual);
// reset data structure
void reinitialize(bool nodeUpdated);
// enforce constraints in CG solve
void enforceConstraint(TVStack& x)
{
projection.enforceConstraint(x);
updateVelocity(x);
}
// add dv to velocity
void updateVelocity(const TVStack& dv);
void setConstraintDirections()
//set constraints as projections
void setConstraints()
{
projection.setConstraintDirections();
projection.setConstraints();
}
// update the projections and project the residual
void project(TVStack& r, const TVStack& dv)
{
updateProjection(dv);
projection(r);
}
// perform precondition M^(-1) x = b
void precondition(const TVStack& x, TVStack& b)
{
m_preconditioner->operator()(x,b);

49
src/BulletSoftBody/btCGProjection.h
View File

@ -17,12 +17,12 @@ struct Constraint
btAlignedObjectArray<const btSoftBody::RContact*> m_contact;
btAlignedObjectArray<btVector3> m_direction;
btAlignedObjectArray<btScalar> m_value;
// the magnitude of the total impulse the node applied to the rb in the normal direction in the cg solve
btAlignedObjectArray<btScalar> m_accumulated_normal_impulse;
Constraint(const btSoftBody::RContact& rcontact)
{
m_contact.push_back(&rcontact);
m_direction.push_back(rcontact.m_cti.m_normal);
m_value.push_back(0);
append(rcontact);
}
Constraint(const btVector3 dir)
@ -30,30 +30,56 @@ struct Constraint
m_contact.push_back(nullptr);
m_direction.push_back(dir);
m_value.push_back(0);
m_accumulated_normal_impulse.push_back(0);
}
Constraint()
{
m_contact.push_back(nullptr);
m_direction.push_back(btVector3(0,0,0));
m_value.push_back(0);
m_accumulated_normal_impulse.push_back(0);
}
void append(const btSoftBody::RContact& rcontact)
{
m_contact.push_back(&rcontact);
m_direction.push_back(rcontact.m_cti.m_normal);
m_value.push_back(0);
m_accumulated_normal_impulse.push_back(0);
}
~Constraint()
{
}
};
struct Friction
{
btAlignedObjectArray<bool> m_static;
btAlignedObjectArray<btScalar> m_impulse;
btAlignedObjectArray<btScalar> m_dv;
btAlignedObjectArray<btVector3> m_direction;
btAlignedObjectArray<btVector3> m_direction_prev;
btAlignedObjectArray<bool> m_static; // whether the friction is static
btAlignedObjectArray<btScalar> m_impulse; // the impulse magnitude the node feels
btAlignedObjectArray<btScalar> m_dv; // the dv magnitude of the node
btAlignedObjectArray<btVector3> m_direction; // the direction of the friction for the node
btAlignedObjectArray<bool> m_static_prev;
btAlignedObjectArray<btScalar> m_impulse_prev;
btAlignedObjectArray<btScalar> m_dv_prev;
btAlignedObjectArray<btVector3> m_direction_prev;
btAlignedObjectArray<bool> m_released;
btAlignedObjectArray<bool> m_released; // whether the contact is released
btAlignedObjectArray<btScalar> m_accumulated_normal_impulse;
// the total impulse the node applied to the rb in the tangential direction in the cg solve
btAlignedObjectArray<btVector3> m_accumulated_tangent_impulse;
Friction()
{
append();
}
void append()
{
m_static.push_back(false);
m_static_prev.push_back(false);
@ -67,7 +93,6 @@ struct Friction
m_dv.push_back(0);
m_dv_prev.push_back(0);
m_accumulated_normal_impulse.push_back(0);
m_accumulated_tangent_impulse.push_back(btVector3(0,0,0));
m_released.push_back(false);
}
@ -100,7 +125,7 @@ public:
// apply the constraints
virtual void operator()(TVStack& x) = 0;
virtual void setConstraintDirections() = 0;
virtual void setConstraints() = 0;
// update the constraints
virtual void update(const TVStack& dv, const TVStack& backup_v) = 0;

8
src/BulletSoftBody/btConjugateGradient.h
View File

@ -18,12 +18,10 @@ class btConjugateGradient
using TVStack = btAlignedObjectArray<btVector3>;
TVStack r,p,z,temp;
int max_iterations;
btScalar tolerance;
public:
btConjugateGradient(const int max_it_in)
: max_iterations(max_it_in)
, tolerance(std::numeric_limits<float>::epsilon() * 16)
{
}
@ -121,12 +119,6 @@ public:
return ans;
}
void setZero(TVStack& a)
{
for (int i = 0; i < a.size(); ++i)
a[i].setZero();
}
void multAndAddTo(btScalar s, const TVStack& a, TVStack& result)
{
// result += s*a

201
src/BulletSoftBody/btContactProjection.cpp
View File

@ -61,9 +61,9 @@ void btContactProjection::update(const TVStack& dv, const TVStack& backupVelocit
multibodyLinkCol->m_multiBody->calcAccelerationDeltasMultiDof(&jacobianData.m_jacobians[0], deltaV, jacobianData.scratch_r, jacobianData.scratch_v);
btScalar vel = 0.0;
for (int j = 0; j < ndof; ++j)
for (int k = 0; k < ndof; ++k)
{
vel += multibodyLinkCol->m_multiBody->getVelocityVector()[j] * jac[j];
vel += multibodyLinkCol->m_multiBody->getVelocityVector()[k] * jac[k];
}
va = cti.m_normal * vel * m_dt;
}
@ -75,41 +75,41 @@ void btContactProjection::update(const TVStack& dv, const TVStack& backupVelocit
btVector3 impulse = c->m_c0 * vr;
const btVector3 impulse_normal = c->m_c0 * (cti.m_normal * dn);
const btVector3 impulse_tangent = impulse - impulse_normal;
// start friction handling
// copy old data
friction.m_impulse_prev[j] = friction.m_impulse[j];
friction.m_dv_prev[j] = friction.m_dv[j];
friction.m_static_prev[j] = friction.m_static[j];
// get the current tangent direction
btScalar local_tangent_norm = impulse_tangent.norm();
btVector3 local_tangent_dir = btVector3(0,0,0);
if (local_tangent_norm > SIMD_EPSILON)
local_tangent_dir = impulse_tangent.normalized();
// accumulated impulse on the rb in this and all prev cg iterations
friction.m_accumulated_normal_impulse[j] += impulse_normal.dot(cti.m_normal);
btScalar accumulated_normal = friction.m_accumulated_normal_impulse[j];
constraint.m_accumulated_normal_impulse[j] += impulse_normal.dot(cti.m_normal);
const btScalar& accumulated_normal = constraint.m_accumulated_normal_impulse[j];
// the total tangential impulse required to stop sliding
btVector3 tangent = friction.m_accumulated_tangent_impulse[j] + impulse_tangent;
btScalar tangent_norm = tangent.norm();
// start friction handling
// copy old data
friction.m_impulse_prev[j] = friction.m_impulse[j];
friction.m_dv_prev[j] = friction.m_dv[j];
friction.m_static_prev[j] = friction.m_static[j];
if (accumulated_normal < 0 && tangent_norm > SIMD_EPSILON)
if (accumulated_normal < 0)
{
friction.m_direction[j] = -local_tangent_dir;
btScalar compare1 = -accumulated_normal*c->m_c3;
btScalar compare2 = tangent_norm;
// do not allow switching from static friction to dynamic friction
// it causes cg to explode
if (-accumulated_normal*c->m_c3 < tangent_norm && friction.m_static_prev[j] == false && friction.m_released[j] == false)
{
friction.m_static[j] = false;
friction.m_impulse[j] = -accumulated_normal*c->m_c3;
friction.m_dv[j] = 0;
impulse = impulse_normal + (friction.m_impulse_prev[j] * friction.m_direction_prev[j])-(friction.m_impulse[j] * friction.m_direction[j]);
}
else
{
friction.m_static[j] = true;
friction.m_impulse[j] = 0;
friction.m_dv[j] = local_tangent_norm * c->m_c2/m_dt;
impulse = impulse_normal + impulse_tangent;
friction.m_impulse[j] = local_tangent_norm;
}
}
else
@ -117,27 +117,29 @@ void btContactProjection::update(const TVStack& dv, const TVStack& backupVelocit
friction.m_released[j] = true;
friction.m_static[j] = false;
friction.m_impulse[j] = 0;
friction.m_dv[j] = 0;
friction.m_direction[j] = btVector3(0,0,0);
impulse = impulse_normal;
}
friction.m_dv[j] = friction.m_impulse[j] * c->m_c2/m_dt;
friction.m_accumulated_tangent_impulse[j] = -friction.m_impulse[j] * friction.m_direction[j];
// the incremental impulse applied to rb in the tangential direction
btVector3 incremental_tangent = (friction.m_impulse_prev[j] * friction.m_direction_prev[j])-(friction.m_impulse[j] * friction.m_direction[j]);
if (1) // in the same CG solve, the set of constraits doesn't change
// if (dn <= SIMD_EPSILON)
{
// c0 is the impulse matrix, c3 is 1 - the friction coefficient or 0, c4 is the contact hardness coefficient
// dv = new_impulse + accumulated velocity change in previous CG iterations
// so we have the invariant node->m_v = backupVelocity + dv;
btVector3 dv = -impulse * c->m_c2/m_dt + c->m_node->m_v - backupVelocity[m_indices[c->m_node]];
btScalar dvn = dv.dot(cti.m_normal);
// btVector3 dv = -impulse_normal * c->m_c2/m_dt + c->m_node->m_v - backupVelocity[m_indices[c->m_node]];
// btScalar dvn = dv.dot(cti.m_normal);
btScalar dvn = -accumulated_normal * c->m_c2/m_dt;
constraint.m_value[j] = dvn;
// the incremental impulse:
// in the normal direction it's the normal component of "impulse"
// in the tangent direction it's the difference between the frictional impulse in the iteration and the previous iteration
impulse = impulse_normal + (friction.m_impulse_prev[j] * friction.m_direction_prev[j])-(friction.m_impulse[j] * friction.m_direction[j]);
// impulse = impulse_normal;
impulse = impulse_normal + incremental_tangent;
if (cti.m_colObj->getInternalType() == btCollisionObject::CO_RIGID_BODY)
{
if (rigidCol)
@ -147,7 +149,7 @@ void btContactProjection::update(const TVStack& dv, const TVStack& backupVelocit
{
if (multibodyLinkCol)
{
double multiplier = 1;
double multiplier = 0.5;
multibodyLinkCol->m_multiBody->applyDeltaVeeMultiDof(deltaV, -impulse.length() * multiplier);
}
}
@ -158,8 +160,7 @@ void btContactProjection::update(const TVStack& dv, const TVStack& backupVelocit
}
}
void btContactProjection::setConstraintDirections()
void btContactProjection::setConstraints()
{
// set Dirichlet constraint
for (int i = 0; i < m_softBodies.size(); ++i)
@ -188,6 +189,7 @@ void btContactProjection::setConstraintDirections()
{
btSoftBody* psb = m_softBodies[i];
btMultiBodyJacobianData jacobianData;
btAlignedObjectArray<btScalar> jacobian;
for (int j = 0; j < psb->m_rcontacts.size(); ++j)
{
@ -214,6 +216,7 @@ void btContactProjection::setConstraintDirections()
}
else if (cti.m_colObj->getInternalType() == btCollisionObject::CO_FEATHERSTONE_LINK)
{
jacobian.clear();
multibodyLinkCol = (btMultiBodyLinkCollider*)btMultiBodyLinkCollider::upcast(cti.m_colObj);
if (multibodyLinkCol)
{
@ -227,9 +230,11 @@ void btContactProjection::setConstraintDirections()
multibodyLinkCol->m_multiBody->calcAccelerationDeltasMultiDof(&jacobianData.m_jacobians[0], deltaV, jacobianData.scratch_r, jacobianData.scratch_v);
btScalar vel = 0.0;
jacobian.resize(ndof);
for (int j = 0; j < ndof; ++j)
{
vel += multibodyLinkCol->m_multiBody->getVelocityVector()[j] * jac[j];
jacobian[j] = jac[j];
}
va = cti.m_normal * vel * m_dt;
}
@ -262,22 +267,10 @@ void btContactProjection::setConstraintDirections()
btScalar dot_prod = dirs[0].dot(cti.m_normal);
if (std::abs(std::abs(dot_prod) - 1) < angle_epsilon)
{
constraints[j].m_contact.push_back(&c);
constraints[j].m_direction.push_back(cti.m_normal);
constraints[j].m_value.push_back(0);
// group the constraints
constraints[j].append(c);
// push in an empty friction
frictions[j].m_direction.push_back(btVector3(0,0,0));
frictions[j].m_direction_prev.push_back(btVector3(0,0,0));
frictions[j].m_impulse.push_back(0);
frictions[j].m_impulse_prev.push_back(0);
frictions[j].m_dv.push_back(0);
frictions[j].m_dv_prev.push_back(0);
frictions[j].m_static.push_back(false);
frictions[j].m_static_prev.push_back(false);
frictions[j].m_accumulated_normal_impulse.push_back(0);
frictions[j].m_accumulated_tangent_impulse.push_back(btVector3(0,0,0));
frictions[j].m_released.push_back(false);
frictions[j].append();
merged = true;
break;
}
@ -295,3 +288,127 @@ void btContactProjection::setConstraintDirections()
}
}
}
void btContactProjection::enforceConstraint(TVStack& x)
{
const int dim = 3;
for (auto& it : m_constraints)
{
const btAlignedObjectArray<Constraint>& constraints = it.second;
size_t i = m_indices[it.first];
const btAlignedObjectArray<Friction>& frictions = m_frictions[it.first];
btAssert(constraints.size() <= dim);
btAssert(constraints.size() > 0);
if (constraints.size() == 1)
{
x[i] -= x[i].dot(constraints[0].m_direction[0]) * constraints[0].m_direction[0];
for (int j = 0; j < constraints[0].m_direction.size(); ++j)
x[i] += constraints[0].m_value[j] * constraints[0].m_direction[j];
}
else if (constraints.size() == 2)
{
btVector3 free_dir = btCross(constraints[0].m_direction[0], constraints[1].m_direction[0]);
btAssert(free_dir.norm() > SIMD_EPSILON)
free_dir.normalize();
x[i] = x[i].dot(free_dir) * free_dir;
for (int j = 0; j < constraints.size(); ++j)
{
for (int k = 0; k < constraints[j].m_direction.size(); ++k)
{
x[i] += constraints[j].m_value[k] * constraints[j].m_direction[k];
}
}
}
else
{
x[i].setZero();
for (int j = 0; j < constraints.size(); ++j)
{
for (int k = 0; k < constraints[j].m_direction.size(); ++k)
{
x[i] += constraints[j].m_value[k] * constraints[j].m_direction[k];
}
}
}
// apply friction if the node is not constrained in all directions
if (constraints.size() < 3)
{
for (int f = 0; f < frictions.size(); ++f)
{
const Friction& friction= frictions[f];
for (int j = 0; j < friction.m_direction.size(); ++j)
{
// clear the old constraint
if (friction.m_static_prev[j] == true)
{
x[i] -= friction.m_direction_prev[j] * friction.m_dv_prev[j];
}
// add the new constraint
if (friction.m_static[j] == true)
{
x[i] += friction.m_direction[j] * friction.m_dv[j];
}
}
}
}
}
}
void btContactProjection::operator()(TVStack& x)
{
const int dim = 3;
for (auto& it : m_constraints)
{
const btAlignedObjectArray<Constraint>& constraints = it.second;
size_t i = m_indices[it.first];
btAlignedObjectArray<Friction>& frictions = m_frictions[it.first];
btAssert(constraints.size() <= dim);
btAssert(constraints.size() > 0);
if (constraints.size() == 1)
{
x[i] -= x[i].dot(constraints[0].m_direction[0]) * constraints[0].m_direction[0];
}
else if (constraints.size() == 2)
{
btVector3 free_dir = btCross(constraints[0].m_direction[0], constraints[1].m_direction[0]);
btAssert(free_dir.norm() > SIMD_EPSILON)
free_dir.normalize();
x[i] = x[i].dot(free_dir) * free_dir;
}
else
x[i].setZero();
// apply friction if the node is not constrained in all directions
if (constraints.size() < 3)
{
bool has_static_constraint = false;
for (int f = 0; f < frictions.size(); ++f)
{
Friction& friction= frictions[f];
for (int j = 0; j < friction.m_static.size(); ++j)
has_static_constraint = has_static_constraint || friction.m_static[j];
}
for (int f = 0; f < frictions.size(); ++f)
{
Friction& friction= frictions[f];
for (int j = 0; j < friction.m_direction.size(); ++j)
{
// clear the old friction force
if (friction.m_static_prev[j] == false)
{
x[i] -= friction.m_direction_prev[j] * friction.m_impulse_prev[j];
}
// only add to the rhs if there is no static friction constraint on the node
if (friction.m_static[j] == false && !has_static_constraint)
{
x[i] += friction.m_direction[j] * friction.m_impulse[j];
}
}
}
}
}
}

160
src/BulletSoftBody/btContactProjection.h
View File

@ -18,171 +18,21 @@ public:
btContactProjection(btAlignedObjectArray<btSoftBody *>& softBodies, const btScalar& dt)
: btCGProjection(softBodies, dt)
{
}
virtual ~btContactProjection()
{
}
// apply the constraints
virtual void operator()(TVStack& x)
{
const int dim = 3;
for (auto& it : m_constraints)
{
const btAlignedObjectArray<Constraint>& constraints = it.second;
size_t i = m_indices[it.first];
btAlignedObjectArray<Friction>& frictions = m_frictions[it.first];
btAssert(constraints.size() <= dim);
btAssert(constraints.size() > 0);
if (constraints.size() == 1)
{
x[i] -= x[i].dot(constraints[0].m_direction[0]) * constraints[0].m_direction[0];
Friction& friction= frictions[0];
bool has_static_constraint = false;
for (int j = 0; j < friction.m_static.size(); ++j)
has_static_constraint = has_static_constraint || friction.m_static[j];
for (int j = 0; j < friction.m_direction.size(); ++j)
{
// clear the old friction force
if (friction.m_static_prev[j] == false)
{
x[i] -= friction.m_direction_prev[j] * friction.m_impulse_prev[j];
}
// only add to the rhs if there is no static friction constraint on the node
if (friction.m_static[j] == false && !has_static_constraint)
{
x[i] += friction.m_direction[j] * friction.m_impulse[j];
}
}
}
else if (constraints.size() == 2)
{
// TODO : friction
btVector3 free_dir = btCross(constraints[0].m_direction[0], constraints[1].m_direction[0]);
btAssert(free_dir.norm() > SIMD_EPSILON)
free_dir.normalize();
x[i] = x[i].dot(free_dir) * free_dir;
bool has_static_constraint = false;
for (int f = 0; f < 2; ++f)
{
Friction& friction= frictions[f];
for (int j = 0; j < friction.m_static.size(); ++j)
has_static_constraint = has_static_constraint || friction.m_static[j];
}
for (int f = 0; f < 2; ++f)
{
Friction& friction= frictions[f];
for (int j = 0; j < friction.m_direction.size(); ++j)
{
// clear the old friction force
if (friction.m_static_prev[j] == false)
{
x[i] -= friction.m_direction_prev[j] * friction.m_impulse_prev[j];
}
// only add to the rhs if there is no static friction constraint on the node
if (friction.m_static[j] == false && !has_static_constraint)
{
x[i] += friction.m_direction[j] * friction.m_impulse[j];
}
}
}
}
else
x[i].setZero();
}
}
// apply the constraints to the rhs
virtual void operator()(TVStack& x);
virtual void enforceConstraint(TVStack& x)
{
const int dim = 3;
for (auto& it : m_constraints)
{
const btAlignedObjectArray<Constraint>& constraints = it.second;
size_t i = m_indices[it.first];
const btAlignedObjectArray<Friction>& frictions = m_frictions[it.first];
btAssert(constraints.size() <= dim);
btAssert(constraints.size() > 0);
if (constraints.size() == 1)
{
x[i] -= x[i].dot(constraints[0].m_direction[0]) * constraints[0].m_direction[0];
for (int j = 0; j < constraints[0].m_direction.size(); ++j)
x[i] += constraints[0].m_value[j] * constraints[0].m_direction[j];
const Friction& friction= frictions[0];
for (int j = 0; j < friction.m_direction.size(); ++j)
{
// clear the old constraint
if (friction.m_static_prev[j] == true)
{
// x[i] -= friction.m_direction_prev[j] * friction.m_dv_prev[j];
}
// add the new constraint
if (friction.m_static[j] == true)
{
x[i] += friction.m_direction[j] * friction.m_dv[j];
}
}
}
else if (constraints.size() == 2)
{
// TODO: friction
btVector3 free_dir = btCross(constraints[0].m_direction[0], constraints[1].m_direction[0]);
btAssert(free_dir.norm() > SIMD_EPSILON)
free_dir.normalize();
x[i] = x[i].dot(free_dir) * free_dir;
for (int j = 0; j < constraints.size(); ++j)
{
for (int k = 0; k < constraints[j].m_direction.size(); ++k)
{
x[i] += constraints[j].m_value[k] * constraints[j].m_direction[k];
}
}
for (int f = 0; f < 2; ++f)
{
const Friction& friction= frictions[f];
for (int j = 0; j < friction.m_direction.size(); ++j)
{
// clear the old constraint
if (friction.m_static_prev[j] == true)
{
// x[i] -= friction.m_direction_prev[j] * friction.m_dv_prev[j];
}
// add the new constraint
if (friction.m_static[j] == true)
{
x[i] += friction.m_direction[j] * friction.m_dv[j];
}
}
}
}
else
{
x[i].setZero();
for (int j = 0; j < constraints.size(); ++j)
{
for (int k = 0; k < constraints[j].m_direction.size(); ++k)
{
x[i] += constraints[j].m_value[k] * constraints[j].m_direction[k];
}
}
}
}
}
// apply constraints to x in Ax=b
virtual void enforceConstraint(TVStack& x);
// update the constraints
virtual void update(const TVStack& dv, const TVStack& backupVelocity);
virtual void setConstraintDirections();
virtual void setConstraints();
};
#endif /* btContactProjection_h */

78
src/BulletSoftBody/btDeformableBodySolver.cpp
View File

@ -122,14 +122,15 @@ void btDeformableBodySolver::solveConstraints(float solverdt)
// apply explicit force
m_objective->applyExplicitForce(m_residual);
// remove contact constraints with separating velocity
setConstraintDirections();
// add constraints to the solver
setConstraints();
backupVelocity();
for (int i = 0; i < m_solveIterations; ++i)
{
m_objective->computeResidual(solverdt, m_residual);
m_objective->initialGuess(m_dv, m_residual);
m_objective->computeStep(m_dv, m_residual, solverdt);
updateVelocity();
}
@ -153,9 +154,9 @@ void btDeformableBodySolver::reinitialize(bool nodeUpdated)
m_objective->reinitialize(nodeUpdated);
}
void btDeformableBodySolver::setConstraintDirections()
void btDeformableBodySolver::setConstraints()
{
m_objective->setConstraintDirections();
m_objective->setConstraints();
}
void btDeformableBodySolver::setWorld(btDeformableRigidDynamicsWorld* world)
@ -173,9 +174,76 @@ void btDeformableBodySolver::updateVelocity()
btSoftBody* psb = m_softBodySet[i];
for (int j = 0; j < psb->m_nodes.size(); ++j)
{
// psb->m_nodes[j].m_v += m_dv[counter];
psb->m_nodes[j].m_v = m_backupVelocity[counter]+m_dv[counter];
++counter;
}
}
}
void btDeformableBodySolver::advect(btScalar dt)
{
for (int i = 0; i < m_softBodySet.size(); ++i)
{
btSoftBody* psb = m_softBodySet[i];
for (int j = 0; j < psb->m_nodes.size(); ++j)
{
auto& node = psb->m_nodes[j];
node.m_x = node.m_q + dt * node.m_v;
}
}
}
void btDeformableBodySolver::backupVelocity()
{
// serial implementation
int counter = 0;
for (int i = 0; i < m_softBodySet.size(); ++i)
{
btSoftBody* psb = m_softBodySet[i];
for (int j = 0; j < psb->m_nodes.size(); ++j)
{
m_backupVelocity[counter++] = psb->m_nodes[j].m_v;
}
}
}
bool btDeformableBodySolver::updateNodes()
{
int numNodes = 0;
for (int i = 0; i < m_softBodySet.size(); ++i)
numNodes += m_softBodySet[i]->m_nodes.size();
if (numNodes != m_numNodes)
{
m_numNodes = numNodes;
m_backupVelocity.resize(numNodes);
return true;
}
return false;
}
void btDeformableBodySolver::predictMotion(float solverdt)
{
for (int i = 0; i < m_softBodySet.size(); ++i)
{
btSoftBody *psb = m_softBodySet[i];
if (psb->isActive())
{
psb->predictMotion(solverdt);
}
}
}
void btDeformableBodySolver::updateSoftBodies()
{
for (int i = 0; i < m_softBodySet.size(); i++)
{
btSoftBody *psb = (btSoftBody *)m_softBodySet[i];
if (psb->isActive())
{
psb->integrateMotion(); // normal is updated here
}
}
}

69
src/BulletSoftBody/btDeformableBodySolver.h
View File

@ -51,17 +51,7 @@ public:
return true;
}
virtual void updateSoftBodies()
{
for (int i = 0; i < m_softBodySet.size(); i++)
{
btSoftBody *psb = (btSoftBody *)m_softBodySet[i];
if (psb->isActive())
{
psb->integrateMotion(); // normal is updated here
}
}
}
virtual void updateSoftBodies();
virtual void optimize(btAlignedObjectArray<btSoftBody *> &softBodies, bool forceUpdate = false)
{
@ -76,64 +66,17 @@ public:
void reinitialize(bool nodeUpdated);
void setConstraintDirections();
void setConstraints();
void advect(btScalar dt)
{
size_t counter = 0;
for (int i = 0; i < m_softBodySet.size(); ++i)
{
btSoftBody* psb = m_softBodySet[i];
for (int j = 0; j < psb->m_nodes.size(); ++j)
{
auto& node = psb->m_nodes[j];
node.m_x = node.m_q + dt * node.m_v;
}
}
}
void advect(btScalar dt);
void backupVelocity()
{
// serial implementation
int counter = 0;
for (int i = 0; i < m_softBodySet.size(); ++i)
{
btSoftBody* psb = m_softBodySet[i];
for (int j = 0; j < psb->m_nodes.size(); ++j)
{
m_backupVelocity[counter++] = psb->m_nodes[j].m_v;
}
}
}
void backupVelocity();
void updateVelocity();
bool updateNodes()
{
int numNodes = 0;
for (int i = 0; i < m_softBodySet.size(); ++i)
numNodes += m_softBodySet[i]->m_nodes.size();
if (numNodes != m_numNodes)
{
m_numNodes = numNodes;
m_backupVelocity.resize(numNodes);
return true;
}
return false;
}
bool updateNodes();
virtual void predictMotion(float solverdt)
{
for (int i = 0; i < m_softBodySet.size(); ++i)
{
btSoftBody *psb = m_softBodySet[i];
if (psb->isActive())
{
psb->predictMotion(solverdt);
}
}
}
virtual void predictMotion(float solverdt);
virtual void copySoftBodyToVertexBuffer(const btSoftBody *const softBody, btVertexBufferDescriptor *vertexBuffer) {}

67
src/BulletSoftBody/btPreconditioner.h Normal file
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@ -0,0 +1,67 @@
//
// btPreconditioner.h
// BulletSoftBody
//
// Created by Xuchen Han on 7/18/19.
//
#ifndef BT_PRECONDITIONER_H
#define BT_PRECONDITIONER_H
class Preconditioner
{
public:
using TVStack = btAlignedObjectArray<btVector3>;
virtual void operator()(const TVStack& x, TVStack& b) = 0;
virtual void reinitialize(bool nodeUpdated) = 0;
};
class DefaultPreconditioner : public Preconditioner
{
public:
virtual void operator()(const TVStack& x, TVStack& b)
{
btAssert(b.size() == x.size());
for (int i = 0; i < b.size(); ++i)
b[i] = x[i];
}
virtual void reinitialize(bool nodeUpdated)
{
}
};
class MassPreconditioner : public Preconditioner
{
btAlignedObjectArray<btScalar> m_inv_mass;
const btAlignedObjectArray<btSoftBody *>& m_softBodies;
public:
MassPreconditioner(const btAlignedObjectArray<btSoftBody *>& softBodies)
: m_softBodies(softBodies)
{
}
virtual void reinitialize(bool nodeUpdated)
{
if (nodeUpdated)
{
m_inv_mass.clear();
for (int i = 0; i < m_softBodies.size(); ++i)
{
btSoftBody* psb = m_softBodies[i];
for (int j = 0; j < psb->m_nodes.size(); ++j)
m_inv_mass.push_back(psb->m_nodes[j].m_im);
}
}
}
virtual void operator()(const TVStack& x, TVStack& b)
{
btAssert(b.size() == x.size());
btAssert(m_inv_mass.size() == x.size());
for (int i = 0; i < b.size(); ++i)
b[i] = x[i] * m_inv_mass[i];
}
};
#endif /* BT_PRECONDITIONER_H */