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+ add option to set pre-tick callback, called at the beginning of each internal simulation step

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+ use real-time for soft body demo (using this pre-tick callback)
+ optimize the generation of bending constraints for the special case where the distance is 2
This commit is contained in:
erwin.coumans
2009-08-14 21:36:51 +00:00
parent e89fe1cbfa
commit 34699f6de6
5 changed files with 135 additions and 40 deletions
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74
Demos/SoftDemo/SoftDemo.cpp
View File

@@ -98,6 +98,41 @@ void SoftDemo::createStack( btCollisionShape* boxShape, float halfCubeSize, int
extern int gNumManifold;
extern int gOverlappingPairs;
///for mouse picking
void pickingPreTickCallback (btDynamicsWorld *world, btScalar timeStep)
{
SoftDemo* softDemo = (SoftDemo*)world->getWorldUserInfo();
if(softDemo->m_drag)
{
const int x=softDemo->m_lastmousepos[0];
const int y=softDemo->m_lastmousepos[1];
const btVector3 rayFrom=softDemo->getCameraPosition();
const btVector3 rayTo=softDemo->getRayTo(x,y);
const btVector3 rayDir=(rayTo-rayFrom).normalized();
const btVector3 N=(softDemo->getCameraTargetPosition()-softDemo->getCameraPosition()).normalized();
const btScalar O=btDot(softDemo->m_impact,N);
const btScalar den=btDot(N,rayDir);
if((den*den)>0)
{
const btScalar num=O-btDot(N,rayFrom);
const btScalar hit=num/den;
if((hit>0)&&(hit<1500))
{
softDemo->m_goal=rayFrom+rayDir*hit;
}
}
btVector3 delta=softDemo->m_goal-softDemo->m_node->m_x;
static const btScalar maxdrag=10;
if(delta.length2()>(maxdrag*maxdrag))
{
delta=delta.normalized()*maxdrag;
}
softDemo->m_node->m_v+=delta/timeStep;
}
}
void SoftDemo::clientMoveAndDisplay()
{
@@ -106,39 +141,17 @@ void SoftDemo::clientMoveAndDisplay()
float dt = 1.0/60.;
float ms = getDeltaTimeMicroseconds();
float dt = ms / 1000000.f;//1.0/60.;
if (m_dynamicsWorld)
{
if(m_drag)
{
const int x=m_lastmousepos[0];
const int y=m_lastmousepos[1];
const btVector3 rayFrom=m_cameraPosition;
const btVector3 rayTo=getRayTo(x,y);
const btVector3 rayDir=(rayTo-rayFrom).normalized();
const btVector3 N=(m_cameraTargetPosition-m_cameraPosition).normalized();
const btScalar O=btDot(m_impact,N);
const btScalar den=btDot(N,rayDir);
if((den*den)>0)
{
const btScalar num=O-btDot(N,rayFrom);
const btScalar hit=num/den;
if((hit>0)&&(hit<1500))
{
m_goal=rayFrom+rayDir*hit;
}
}
btVector3 delta=m_goal-m_node->m_x;
static const btScalar maxdrag=10;
if(delta.length2()>(maxdrag*maxdrag))
{
delta=delta.normalized()*maxdrag;
}
m_node->m_v+=delta/dt;
}
#define FIXED_STEP
//#define FIXED_STEP
#ifdef FIXED_STEP
m_dynamicsWorld->stepSimulation(dt=1.0f/60.f,0);
@@ -1246,7 +1259,7 @@ static void Init_ClusterStackMixed(SoftDemo* pdemo)
}
}
unsigned current_demo=18;
unsigned current_demo=19;
void SoftDemo::clientResetScene()
{
@@ -1711,6 +1724,7 @@ void SoftDemo::initPhysics()
btDiscreteDynamicsWorld* world = new btSoftRigidDynamicsWorld(m_dispatcher,m_broadphase,m_solver,m_collisionConfiguration);
m_dynamicsWorld = world;
m_dynamicsWorld->setInternalTickCallback(pickingPreTickCallback,this,true);
m_dynamicsWorld->getDispatchInfo().m_enableSPU = true;

4
src/BulletDynamics/Dynamics/btContinuousDynamicsWorld.cpp
View File

@@ -48,6 +48,10 @@ void btContinuousDynamicsWorld::internalSingleStepSimulation( btScalar timeStep)
startProfiling(timeStep);
if(0 != m_internalPreTickCallback) {
(*m_internalPreTickCallback)(this, timeStep);
}
///update aabbs information
updateAabbs();

4
src/BulletDynamics/Dynamics/btDiscreteDynamicsWorld.cpp
View File

@@ -362,6 +362,10 @@ void btDiscreteDynamicsWorld::internalSingleStepSimulation(btScalar timeStep)
BT_PROFILE("internalSingleStepSimulation");
if(0 != m_internalPreTickCallback) {
(*m_internalPreTickCallback)(this, timeStep);
}
///apply gravity, predict motion
predictUnconstraintMotion(timeStep);

13
src/BulletDynamics/Dynamics/btDynamicsWorld.h
View File

@@ -41,6 +41,7 @@ class btDynamicsWorld : public btCollisionWorld
protected:
btInternalTickCallback m_internalTickCallback;
btInternalTickCallback m_internalPreTickCallback;
void* m_worldUserInfo;
btContactSolverInfo m_solverInfo;
@@ -49,7 +50,7 @@ public:
btDynamicsWorld(btDispatcher* dispatcher,btBroadphaseInterface* broadphase,btCollisionConfiguration* collisionConfiguration)
:btCollisionWorld(dispatcher,broadphase,collisionConfiguration), m_internalTickCallback(0), m_worldUserInfo(0)
:btCollisionWorld(dispatcher,broadphase,collisionConfiguration), m_internalTickCallback(0),m_internalPreTickCallback(0), m_worldUserInfo(0)
{
}
@@ -102,9 +103,15 @@ public:
virtual void clearForces() = 0;
/// Set the callback for when an internal tick (simulation substep) happens, optional user info
void setInternalTickCallback(btInternalTickCallback cb, void* worldUserInfo=0)
void setInternalTickCallback(btInternalTickCallback cb, void* worldUserInfo=0,bool isPreTick=false)
{
m_internalTickCallback = cb;
if (isPreTick)
{
m_internalPreTickCallback = cb;
} else
{
m_internalTickCallback = cb;
}
m_worldUserInfo = worldUserInfo;
}

80
src/BulletSoftBody/btSoftBody.cpp
View File

@@ -704,6 +704,9 @@ void btSoftBody::clusterDCImpulse(Cluster* cluster,const btVector3& impulse)
cluster->m_ndimpulses++;
}
//
int btSoftBody::generateBendingConstraints(int distance,Material* mat)
{
@@ -715,14 +718,21 @@ int btSoftBody::generateBendingConstraints(int distance,Material* mat)
const int n=m_nodes.size();
const unsigned inf=(~(unsigned)0)>>1;
unsigned* adj=new unsigned[n*n];
#define IDX(_x_,_y_) ((_y_)*n+(_x_))
for(j=0;j<n;++j)
{
for(i=0;i<n;++i)
{
if(i!=j) adj[IDX(i,j)]=adj[IDX(j,i)]=inf;
if(i!=j)
{
adj[IDX(i,j)]=adj[IDX(j,i)]=inf;
}
else
{
adj[IDX(i,j)]=adj[IDX(j,i)]=0;
}
}
}
for( i=0;i<m_links.size();++i)
@@ -732,20 +742,76 @@ int btSoftBody::generateBendingConstraints(int distance,Material* mat)
adj[IDX(ia,ib)]=1;
adj[IDX(ib,ia)]=1;
}
for(int k=0;k<n;++k)
//special optimized case for distance == 2
if (distance == 2)
{
for(j=0;j<n;++j)
struct NodeLinks
{
for(i=j+1;i<n;++i)
btAlignedObjectArray<int> m_links;
};
btAlignedObjectArray<NodeLinks> nodeLinks;
/* Build node links */
nodeLinks.resize(m_nodes.size());
for( i=0;i<m_links.size();++i)
{
const int ia=(int)(m_links[i].m_n[0]-&m_nodes[0]);
const int ib=(int)(m_links[i].m_n[1]-&m_nodes[0]);
if (nodeLinks[ia].m_links.findLinearSearch(ib)==nodeLinks[ia].m_links.size())
nodeLinks[ia].m_links.push_back(ib);
if (nodeLinks[ib].m_links.findLinearSearch(ia)==nodeLinks[ib].m_links.size())
nodeLinks[ib].m_links.push_back(ia);
}
for (int ii=0;ii<nodeLinks.size();ii++)
{
int i=ii;
for (int jj=0;jj<nodeLinks[ii].m_links.size();jj++)
{
const unsigned sum=adj[IDX(i,k)]+adj[IDX(k,j)];
if(adj[IDX(i,j)]>sum)
int k = nodeLinks[ii].m_links[jj];
for (int kk=0;kk<nodeLinks[k].m_links.size();kk++)
{
adj[IDX(i,j)]=adj[IDX(j,i)]=sum;
int j = nodeLinks[k].m_links[kk];
if (i!=j)
{
const unsigned sum=adj[IDX(i,k)]+adj[IDX(k,j)];
btAssert(sum==2);
if(adj[IDX(i,j)]>sum)
{
adj[IDX(i,j)]=adj[IDX(j,i)]=sum;
}
}
}
}
}
} else
{
///generic Floyd's algorithm
for(int k=0;k<n;++k)
{
for(j=0;j<n;++j)
{
for(i=j+1;i<n;++i)
{
const unsigned sum=adj[IDX(i,k)]+adj[IDX(k,j)];
if(adj[IDX(i,j)]>sum)
{
adj[IDX(i,j)]=adj[IDX(j,i)]=sum;
}
}
}
}
}
/* Build links */
int nlinks=0;
for(j=0;j<n;++j)