Hi guys, I’m new to the forums, so I’ll try and fit in.
I’m currently having this issue with a basic cloth, the actual setup of Physx works fine, as I’m able to create some simple bouncing boxes, so it’s another issue. What happens is that the cloth i create basically flickers all the time (visually) for some weird reason, I suspect that the setup isn’t correct, though I might be wrong.
What I have so far: (Please keep in mind that the purpose of this piece of code isn’t optimization yet…)
PhysicalMeshes.push_back(CEPHYSICSHOLDER());
PxClothMeshDesc clothDesc;
clothDesc.setToDefault();
clothDesc.points.count = mesh->VertexCount;
clothDesc.points.stride = sizeof(PxClothParticle);
clothDesc.points.data= (PxClothParticle*)malloc(sizeof(PxClothParticle)*mesh->VertexCount);
clothDesc.triangles.count = mesh->IndexCount/3;
clothDesc.triangles.stride = 3*sizeof(PxU32);
clothDesc.triangles.data= (PxU32*)malloc(sizeof(PxU32)*mesh->IndexCount);
clothDesc.edgeFlags = 0;
PxClothParticle* Vertices = (PxClothParticle*)clothDesc.points.data;
PxU32* Indices = (PxU32*)clothDesc.triangles.data;
until(mesh->VertexCount)
{
PxClothParticle p;
p.pos = PxVec3(mesh->Vertices[i].X, mesh->Vertices[i].Y, mesh->Vertices[i].Z);
p.invWeight = 1.0f/1.0f;
Vertices[i] = p;
}
until(mesh->IndexCount)
Indices[i] = PxU32(mesh->Indices[i]);
//Make sure everything is fine so far
if(!(clothDesc.isValid()))
CE_ERROR("Mesh invalid", "Fatal Error");
PxTransform transform( PxVec3(mesh->position.x, mesh->position.y, mesh->position.z), PxQuat::createIdentity());
PxToolkit::MemoryOutputStream buf;
bool status = mCooking->cookClothFabric(clothDesc, PxVec3(0, -1, 0), buf);
if(!status) {
CE_ERROR("Px Cooking failed in the creation of cloth", "Fatal Error");
}
PxToolkit::MemoryInputData rb(buf.getData(), buf.getSize());
PxClothFabric* fabric = mPhysics->createClothFabric(rb);
PxClothCollisionData cd;
cd.setToDefault();
cd.numSpheres=1;
cd.pairIndexBuffer=0;
PxClothCollisionSphere box_collider;
box_collider.pos= PxVec3(0.0f,2.0f,0.0f);
box_collider.radius=1;
cd.spheres=&box_collider;
PxCloth* cloth = mPhysics->createCloth(transform,*fabric, Vertices, cd, PxClothFlags());
if(cloth) {
PxClothPhaseSolverConfig bendCfg;
bendCfg.solverType= PxClothPhaseSolverConfig::eFAST;
bendCfg.stiffness = 1;
bendCfg.stretchStiffness = 0.5;
cloth->setPhaseSolverConfig(PxClothFabricPhaseType::eBENDING, bendCfg) ;
cloth->setPhaseSolverConfig(PxClothFabricPhaseType::eSTRETCHING, bendCfg) ;
cloth->setPhaseSolverConfig(PxClothFabricPhaseType::eSHEARING, bendCfg) ;
cloth->setPhaseSolverConfig(PxClothFabricPhaseType::eSTRETCHING_HORIZONTAL, bendCfg) ;
cloth->setDampingCoefficient(0.125f);
cloth->setSolverFrequency(240.0f);
mScene->addActor(*cloth);
}
else
{
CE_ERROR("Cannot create cloth", "Fatal Error");
}
// Prepare the holder
PhysicalMeshes.back().actor = cloth;
PhysicalMeshes.back().ptr = mesh;
PhysicalMeshes.back().isDynamic = true;
PhysicalMeshes.back().isCloth = true;
PhysicalMeshes.back().clothSphereCollider = box_collider;
CEPxActor r;
r._m_pActor = cloth;
r._m_pMesh = mesh;
return r;
And how I update my vertices in the main loop:
//update the cloth data
PxClothReadData* pData = cloth->lockClothReadData();
PxClothParticle* pParticles = const_cast<PxClothParticle*>(pData->particles);
int vCount = mesh->VertexCount;
//update the positions
_until(index, vCount)
{
PxVec3 pos = pData->particles[index].pos;
mesh->Vertices[index].X = pos.x;
mesh->Vertices[index].Y = pos.y;
mesh->Vertices[index].Z = pos.z;
}
pData->unlock();
//update normals
for(size_t i=0;i < mesh->IndexCount;i+=3) {
PxVec3 p1 = PxVec3(ToPxVec3(mesh->Vertices[mesh->Indices[i]]));
PxVec3 p2 = PxVec3(ToPxVec3(mesh->Vertices[mesh->Indices[i+1]]));
PxVec3 p3 = PxVec3(ToPxVec3(mesh->Vertices[mesh->Indices[i+2]]));
PxVec3 n = (p2-p1).cross(p3-p1);
PxVec3 newNorm = n/3.0f;
MESH_STRUCT *m = &mesh->Vertices[mesh->Indices[i]];
MESH_STRUCT *m1 = &mesh->Vertices[mesh->Indices[i+1]];
MESH_STRUCT *m2 = &mesh->Vertices[mesh->Indices[i+2]];
m->Normal.x += newNorm.x/3.0f ;
m->Normal.y += newNorm.y/3.0f ;
m->Normal.z += newNorm.z/3.0f ;
m1->Normal.x += newNorm.x/3.0f ;
m1->Normal.y += newNorm.y/3.0f ;
m1->Normal.z += newNorm.z/3.0f ;
m2->Normal.x += newNorm.x/3.0f ;
m2->Normal.y += newNorm.y/3.0f ;
m2->Normal.z += newNorm.z/3.0f ;
D3DXVec3Normalize(&m->Normal, &m->Normal);
D3DXVec3Normalize(&m1->Normal, &m1->Normal);
D3DXVec3Normalize(&m2->Normal, &m2->Normal);
}
// Just an internal function for updating the vertex buffer, nothing special here...
CDK::UpdateVertexBuffer(dev, devcon, (CDK::Buffer)mesh->UMeshVBuffer, &mesh->Vertices, mesh->VertexCount);