Bart/bullet3
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

add cloth demo to show deformable friction

Browse Source
This commit is contained in:
Xuchen Han
2019-09-19 16:38:45 -07:00
parent 55ebafc755
commit 0501fe1bbd
8 changed files with 333 additions and 22 deletions
Download Patch File Download Diff File Expand all files Collapse all files

251
examples/DeformableDemo/ClothFriction.cpp Normal file
View File

@@ -0,0 +1,251 @@
/*
Bullet Continuous Collision Detection and Physics Library
Copyright (c) 2019 Google Inc. 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.
*/
#include "ClothFriction.h"
///btBulletDynamicsCommon.h is the main Bullet include file, contains most common include files.
#include "btBulletDynamicsCommon.h"
#include "BulletSoftBody/btDeformableMultiBodyDynamicsWorld.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 ClothFriction 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).
class ClothFriction : public CommonRigidBodyBase
{
btAlignedObjectArray<btDeformableLagrangianForce*> m_forces;
public:
ClothFriction(struct GUIHelperInterface* helper)
: CommonRigidBodyBase(helper)
{
}
virtual ~ClothFriction()
{
}
void initPhysics();
void exitPhysics();
void resetCamera()
{
float dist = 12;
float pitch = -50;
float yaw = 120;
float targetPos[3] = {0, -3, 0};
m_guiHelper->resetCamera(dist, yaw, pitch, targetPos[0], targetPos[1], targetPos[2]);
}
void stepSimulation(float deltaTime)
{
float internalTimeStep = 1. / 240.f;
m_dynamicsWorld->stepSimulation(deltaTime, 4, internalTimeStep);
}
virtual const btDeformableMultiBodyDynamicsWorld* getDeformableDynamicsWorld() const
{
return (btDeformableMultiBodyDynamicsWorld*)m_dynamicsWorld;
}
virtual btDeformableMultiBodyDynamicsWorld* getDeformableDynamicsWorld()
{
return (btDeformableMultiBodyDynamicsWorld*)m_dynamicsWorld;
}
virtual void renderScene()
{
CommonRigidBodyBase::renderScene();
btDeformableMultiBodyDynamicsWorld* 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 ClothFriction::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)
btDeformableMultiBodyConstraintSolver* sol = new btDeformableMultiBodyConstraintSolver();
sol->setDeformableSolver(deformableBodySolver);
m_solver = sol;
m_dynamicsWorld = new btDeformableMultiBodyDynamicsWorld(m_dispatcher, m_broadphase, sol, m_collisionConfiguration, deformableBodySolver);
btVector3 gravity = btVector3(0, -10, 0);
m_dynamicsWorld->setGravity(gravity);
getDeformableDynamicsWorld()->getWorldInfo().m_gravity = gravity;
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, -32, 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.);
//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(3);
//add the ground to the dynamics world
m_dynamicsWorld->addRigidBody(body);
}
// create a piece of cloth
{
btScalar s = 4;
btScalar h = 0;
btSoftBody* psb = btSoftBodyHelpers::CreatePatch(getDeformableDynamicsWorld()->getWorldInfo(), btVector3(-s, h, -s),
btVector3(+s, h, -s),
btVector3(-s, h, +s),
btVector3(+s, h, +s),
20,20,
0, true);
psb->getCollisionShape()->setMargin(0.05);
psb->generateBendingConstraints(2);
psb->setTotalMass(1);
psb->m_cfg.kKHR = 1; // collision hardness with kinematic objects
psb->m_cfg.kCHR = 1; // collision hardness with rigid body
psb->m_cfg.kDF = 3;
psb->m_cfg.collisions = btSoftBody::fCollision::SDF_RD;
psb->m_cfg.collisions |= btSoftBody::fCollision::VF_DD;
getDeformableDynamicsWorld()->addSoftBody(psb);
btDeformableMassSpringForce* mass_spring = new btDeformableMassSpringForce(10,1, true);
getDeformableDynamicsWorld()->addForce(psb, mass_spring);
m_forces.push_back(mass_spring);
btDeformableGravityForce* gravity_force = new btDeformableGravityForce(gravity);
getDeformableDynamicsWorld()->addForce(psb, gravity_force);
m_forces.push_back(gravity_force);
h = 2;
s = 2;
btSoftBody* psb2 = btSoftBodyHelpers::CreatePatch(getDeformableDynamicsWorld()->getWorldInfo(), btVector3(-s, h, -s),
btVector3(+s, h, -s),
btVector3(-s, h, +s),
btVector3(+s, h, +s),
10,10,
0, true);
psb2->getCollisionShape()->setMargin(0.05);
psb2->generateBendingConstraints(2);
psb2->setTotalMass(1);
psb2->m_cfg.kKHR = 1; // collision hardness with kinematic objects
psb2->m_cfg.kCHR = 1; // collision hardness with rigid body
psb2->m_cfg.kDF = 20;
psb2->m_cfg.collisions = btSoftBody::fCollision::SDF_RD;
psb2->m_cfg.collisions |= btSoftBody::fCollision::VF_DD;
psb->translate(btVector3(0,0,0));
getDeformableDynamicsWorld()->addSoftBody(psb2);
btDeformableMassSpringForce* mass_spring2 = new btDeformableMassSpringForce(10,1, true);
getDeformableDynamicsWorld()->addForce(psb2, mass_spring2);
m_forces.push_back(mass_spring2);
btDeformableGravityForce* gravity_force2 = new btDeformableGravityForce(gravity);
getDeformableDynamicsWorld()->addForce(psb2, gravity_force2);
m_forces.push_back(gravity_force2);
}
m_guiHelper->autogenerateGraphicsObjects(m_dynamicsWorld);
}
void ClothFriction::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 forces
for (int j = 0; j < m_forces.size(); j++)
{
btDeformableLagrangianForce* force = m_forces[j];
delete force;
}
m_forces.clear();
//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* ClothFrictionCreateFunc(struct CommonExampleOptions& options)
{
return new ClothFriction(options.m_guiHelper);
}

19
examples/DeformableDemo/ClothFriction.h Normal file
View File

@@ -0,0 +1,19 @@
/*
Bullet Continuous Collision Detection and Physics Library
Copyright (c) 2019 Google Inc. 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.
*/
#ifndef CLOTH_FRICTION_H
#define CLOTH_FRICTION_H
class CommonExampleInterface* ClothFrictionCreateFunc(struct CommonExampleOptions& options);
#endif //CLOTH_FRICTION_H

67
examples/DeformableDemo/PinchFriction.cpp
View File

@@ -95,8 +95,8 @@ public:
virtual void renderScene()
{
CommonRigidBodyBase::renderScene();
btDeformableMultiBodyDynamicsWorld* deformableWorld = getDeformableDynamicsWorld();
// btDeformableMultiBodyDynamicsWorld* deformableWorld = getDeformableDynamicsWorld();
//
// for (int i = 0; i < deformableWorld->getSoftBodyArray().size(); i++)
// {
// btSoftBody* psb = (btSoftBody*)deformableWorld->getSoftBodyArray()[i];
@@ -115,7 +115,7 @@ void dynamics2(btScalar time, btDeformableMultiBodyDynamicsWorld* world)
return;
btRigidBody* rb0 = rbs[0];
btScalar pressTime = 0.9;
btScalar liftTime = 2.5;
btScalar liftTime = 10;
btScalar shiftTime = 3.5;
btScalar holdTime = 4.5*1000;
btScalar dropTime = 5.3*1000;
@@ -126,9 +126,9 @@ void dynamics2(btScalar time, btDeformableMultiBodyDynamicsWorld* world)
btVector3 initialTranslationLeft = btVector3(0.5,3,4);
btVector3 initialTranslationRight = btVector3(0.5,3,-4);
btVector3 PinchFrictionVelocityLeft = btVector3(0,0,-.5);
btVector3 PinchFrictionVelocityRight = btVector3(0,0,.5);
btVector3 liftVelocity = btVector3(0,5,0);
btVector3 PinchFrictionVelocityLeft = btVector3(0,0,-1);
btVector3 PinchFrictionVelocityRight = btVector3(0,0,1);
btVector3 liftVelocity = btVector3(0,1,0);
btVector3 shiftVelocity = btVector3(0,0,0);
btVector3 holdVelocity = btVector3(0,0,0);
btVector3 openVelocityLeft = btVector3(0,0,4);
@@ -209,8 +209,8 @@ void dynamics2(btScalar time, btDeformableMultiBodyDynamicsWorld* world)
rb1->setAngularVelocity(btVector3(0,0,0));
rb1->setLinearVelocity(velocity);
rb0->setFriction(20);
rb1->setFriction(20);
rb0->setFriction(200);
rb1->setFriction(200);
}
void PinchFriction::initPhysics()
@@ -260,7 +260,7 @@ void PinchFriction::initPhysics()
btDefaultMotionState* myMotionState = new btDefaultMotionState(groundTransform);
btRigidBody::btRigidBodyConstructionInfo rbInfo(mass, myMotionState, groundShape, localInertia);
btRigidBody* body = new btRigidBody(rbInfo);
body->setFriction(0.5);
body->setFriction(0);
//add the ground to the dynamics world
m_dynamicsWorld->addRigidBody(body);
@@ -274,13 +274,13 @@ void PinchFriction::initPhysics()
TetraCube::getNodes(),
false, true, true);
psb->scale(btVector3(1.5, 1.5, 1.5));
psb->translate(btVector3(0, 4, 1.6));
psb->getCollisionShape()->setMargin(0.15);
psb->scale(btVector3(2, 2, 1));
psb->translate(btVector3(0, 2.1, 2.2));
psb->getCollisionShape()->setMargin(0.03);
psb->setTotalMass(1);
psb->m_cfg.kKHR = 1; // collision hardness with kinematic objects
psb->m_cfg.kCHR = 1; // collision hardness with rigid body
psb->m_cfg.kDF = 2;
psb->m_cfg.kDF = 20;
btSoftBodyHelpers::generateBoundaryFaces(psb);
psb->m_cfg.collisions = btSoftBody::fCollision::SDF_RD;
psb->m_cfg.collisions |= btSoftBody::fCollision::VF_DD;
@@ -290,7 +290,7 @@ void PinchFriction::initPhysics()
getDeformableDynamicsWorld()->addForce(psb, gravity_force);
m_forces.push_back(gravity_force);
btDeformableNeoHookeanForce* neohookean = new btDeformableNeoHookeanForce(20,40);
btDeformableNeoHookeanForce* neohookean = new btDeformableNeoHookeanForce(4,8,.1);
getDeformableDynamicsWorld()->addForce(psb, neohookean);
m_forces.push_back(neohookean);
}
@@ -303,13 +303,13 @@ void PinchFriction::initPhysics()
TetraCube::getNodes(),
false, true, true);
psb2->scale(btVector3(1.5, 1.5, 1.5));
psb2->translate(btVector3(0, 4, -1.6));
psb2->getCollisionShape()->setMargin(0.15);
psb2->scale(btVector3(2, 2, 1));
psb2->translate(btVector3(0, 2.1, -2.2));
psb2->getCollisionShape()->setMargin(0.03);
psb2->setTotalMass(1);
psb2->m_cfg.kKHR = 1; // collision hardness with kinematic objects
psb2->m_cfg.kCHR = 1; // collision hardness with rigid body
psb2->m_cfg.kDF = 2;
psb2->m_cfg.kDF = 20;
psb2->m_cfg.collisions = btSoftBody::fCollision::SDF_RD;
psb2->m_cfg.collisions |= btSoftBody::fCollision::VF_DD;
btSoftBodyHelpers::generateBoundaryFaces(psb2);
@@ -319,11 +319,40 @@ void PinchFriction::initPhysics()
getDeformableDynamicsWorld()->addForce(psb2, gravity_force);
m_forces.push_back(gravity_force);
btDeformableNeoHookeanForce* neohookean = new btDeformableNeoHookeanForce(20,40);
btDeformableNeoHookeanForce* neohookean = new btDeformableNeoHookeanForce(4,8,.1);
getDeformableDynamicsWorld()->addForce(psb2, neohookean);
m_forces.push_back(neohookean);
}
// create a third soft block
{
btSoftBody* psb3 = btSoftBodyHelpers::CreateFromTetGenData(getDeformableDynamicsWorld()->getWorldInfo(),
TetraCube::getElements(),
0,
TetraCube::getNodes(),
false, true, true);
psb3->scale(btVector3(2, 2, 1));
psb3->translate(btVector3(0, 2.1, 0));
psb3->getCollisionShape()->setMargin(0.03);
psb3->setTotalMass(1);
psb3->m_cfg.kKHR = 1; // collision hardness with kinematic objects
psb3->m_cfg.kCHR = 1; // collision hardness with rigid body
psb3->m_cfg.kDF = 20;
psb3->m_cfg.collisions = btSoftBody::fCollision::SDF_RD;
psb3->m_cfg.collisions |= btSoftBody::fCollision::VF_DD;
btSoftBodyHelpers::generateBoundaryFaces(psb3);
getDeformableDynamicsWorld()->addSoftBody(psb3);
btDeformableGravityForce* gravity_force = new btDeformableGravityForce(gravity);
getDeformableDynamicsWorld()->addForce(psb3, gravity_force);
m_forces.push_back(gravity_force);
btDeformableNeoHookeanForce* neohookean = new btDeformableNeoHookeanForce(4,8,.1);
getDeformableDynamicsWorld()->addForce(psb3, neohookean);
m_forces.push_back(neohookean);
}
// add a pair of grippers
createGrip();
m_guiHelper->autogenerateGraphicsObjects(m_dynamicsWorld);