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Fixes / improvements in soft body:

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avoid blow-up due to improper mass calculation for fixed nodes (happened when using clusters)
allow to create collision clusters for each tetrahedron or triangle, when using btSoftBody::generateClusters(0)
tweak soft body demos a bit, only draw debug wireframe if necessary
This commit is contained in:
erwin.coumans
2009-08-28 21:23:54 +00:00
parent f492899499
commit 2ef7c1a457
7 changed files with 218 additions and 68 deletions
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106
src/BulletSoftBody/btSoftBody.cpp
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@@ -1053,10 +1053,50 @@ int btSoftBody::generateClusters(int k,int maxiterations)
releaseCluster(i--);
}
}
} else
{
//create a cluster for each tetrahedron (if tetrahedra exist) or each face
if (m_tetras.size())
{
m_clusters.resize(m_tetras.size());
for(i=0;i<m_clusters.size();++i)
{
m_clusters[i] = new(btAlignedAlloc(sizeof(Cluster),16)) Cluster();
m_clusters[i]->m_collide= true;
}
for (i=0;i<m_tetras.size();i++)
{
for (int j=0;j<4;j++)
{
m_clusters[i]->m_nodes.push_back(m_tetras[i].m_n[j]);
}
}
} else
{
m_clusters.resize(m_faces.size());
for(i=0;i<m_clusters.size();++i)
{
m_clusters[i] = new(btAlignedAlloc(sizeof(Cluster),16)) Cluster();
m_clusters[i]->m_collide= true;
}
for(i=0;i<m_faces.size();++i)
{
for(int j=0;j<3;++j)
{
m_clusters[i]->m_nodes.push_back(m_faces[i].m_n[j]);
}
}
}
}
if (m_clusters.size())
{
initializeClusters();
updateClusters();
//for self-collision
m_clusterConnectivity.resize(m_clusters.size()*m_clusters.size());
{
@@ -1084,10 +1124,9 @@ int btSoftBody::generateClusters(int k,int maxiterations)
}
}
}
return(m_clusters.size());
}
return(0);
return(m_clusters.size());
}
//
@@ -2077,7 +2116,8 @@ void btSoftBody::initializeClusters()
c.m_masses.resize(c.m_nodes.size());
for(int j=0;j<c.m_nodes.size();++j)
{
c.m_masses[j] = c.m_nodes[j]->m_im>0?1/c.m_nodes[j]->m_im:0;
c.m_masses[j] = c.m_nodes[j]->m_im>0?1/c.m_nodes[j]->m_im: BT_LARGE_FLOAT;
//c.m_masses[j] = c.m_nodes[j]->m_im>0?1/c.m_nodes[j]->m_im: 0.f;
c.m_imass += c.m_masses[j];
}
c.m_imass = 1/c.m_imass;
@@ -2107,7 +2147,9 @@ void btSoftBody::initializeClusters()
ii[1][0]=ii[0][1];
ii[2][0]=ii[0][2];
ii[2][1]=ii[1][2];
ii=ii.inverse();
ii = ii.inverse();
/* Frame */
c.m_framexform.setIdentity();
c.m_framexform.setOrigin(c.m_com);
@@ -2481,8 +2523,29 @@ void btSoftBody::CJoint::Solve(btScalar dt,btScalar sor)
impulse.m_velocity += iv+fv*m_friction;
}
impulse.m_velocity=m_massmatrix*impulse.m_velocity*sor;
m_bodies[0].applyImpulse(-impulse,m_rpos[0]);
m_bodies[1].applyImpulse( impulse,m_rpos[1]);
if (m_bodies[0].m_soft==m_bodies[1].m_soft)
{
if ((impulse.m_velocity.getX() ==impulse.m_velocity.getX())&&(impulse.m_velocity.getY() ==impulse.m_velocity.getY())&&
(impulse.m_velocity.getZ() ==impulse.m_velocity.getZ()))
{
if (impulse.m_asVelocity)
{
if (impulse.m_velocity.length() <m_bodies[0].m_soft->m_maxSelfCollisionImpulse)
{
} else
{
m_bodies[0].applyImpulse(-impulse*m_bodies[0].m_soft->m_selfCollisionImpulseFactor,m_rpos[0]);
m_bodies[1].applyImpulse( impulse*m_bodies[0].m_soft->m_selfCollisionImpulseFactor,m_rpos[1]);
}
}
}
} else
{
m_bodies[0].applyImpulse(-impulse,m_rpos[0]);
m_bodies[1].applyImpulse( impulse,m_rpos[1]);
}
}
//
@@ -2684,7 +2747,8 @@ void btSoftBody::PSolve_SContacts(btSoftBody* psb,btScalar,btScalar ti)
c.m_weights);
const btVector3 vr=(n.m_x-n.m_q)-(p-q);
btVector3 corr(0,0,0);
if(btDot(vr,nr)<0)
btScalar dot = btDot(vr,nr);
if(dot<0)
{
const btScalar j=c.m_margin-(btDot(nr,n.m_x)-btDot(nr,p));
corr+=c.m_normal*j;
@@ -2735,10 +2799,14 @@ btSoftBody::psolver_t btSoftBody::getSolver(ePSolver::_ solver)
{
switch(solver)
{
case ePSolver::Anchors: return(&btSoftBody::PSolve_Anchors);
case ePSolver::Linear: return(&btSoftBody::PSolve_Links);
case ePSolver::RContacts: return(&btSoftBody::PSolve_RContacts);
case ePSolver::SContacts: return(&btSoftBody::PSolve_SContacts);
case ePSolver::Anchors:
return(&btSoftBody::PSolve_Anchors);
case ePSolver::Linear:
return(&btSoftBody::PSolve_Links);
case ePSolver::RContacts:
return(&btSoftBody::PSolve_RContacts);
case ePSolver::SContacts:
return(&btSoftBody::PSolve_SContacts);
}
return(0);
}
@@ -2801,8 +2869,14 @@ void btSoftBody::defaultCollisionHandler(btSoftBody* psb)
{
case fCollision::CL_SS:
{
btSoftColliders::CollideCL_SS docollide;
docollide.Process(this,psb);
//support self-collision if CL_SELF flag set
if (this!=psb || psb->m_cfg.collisions&fCollision::CL_SELF)
{
btSoftColliders::CollideCL_SS docollide;
docollide.Process(this,psb);
}
}
break;
case fCollision::VF_SS:
@@ -2829,5 +2903,9 @@ void btSoftBody::defaultCollisionHandler(btSoftBody* psb)
}
}
break;
default:
{
}
}
}