PxQuat slerp(const PxReal t, const PxQuat& left, const PxQuat& right)
{
const PxReal quatEpsilon = (PxReal(1.0e-8f));
PxReal cosine = left.dot(right);
PxReal sign = PxReal(1);
if (cosine < 0)
{
cosine = -cosine;
sign = PxReal(-1);
}
PxReal sine = PxReal(1) - cosine*cosine;
if(sine>=quatEpsilon*quatEpsilon)
{
sine = PxSqrt(sine);
const PxReal angle = PxAtan2(sine, cosine);
const PxReal i_sin_angle = PxReal(1) / sine;
const PxReal leftw = PxSin(angle*(PxReal(1)-t)) * i_sin_angle;
const PxReal rightw = PxSin(angle * t) * i_sin_angle * sign;
return left * leftw + right * rightw;
}
return left;
}
void FixedStepper::substepStrategy(const PxReal stepSize, PxU32& substepCount, PxReal& substepSize)
{
if(mAccumulator > mFixedSubStepSize)
mAccumulator = 0.0f;
// don't step less than the step size, just accumulate
mAccumulator += stepSize;
if(mAccumulator < mFixedSubStepSize)
{
substepCount = 0;
return;
}
substepSize = mFixedSubStepSize;
substepCount = PxMin(PxU32(mAccumulator/mFixedSubStepSize), mMaxSubSteps);
mAccumulator -= PxReal(substepCount)*substepSize;
}
void VariableStepper::substepStrategy(const PxReal stepSize, PxU32& substepCount, PxReal& substepSize)
{
if(mAccumulator > mMaxSubStepSize)
mAccumulator = 0.0f;
// don't step less than the min step size, just accumulate
mAccumulator += stepSize;
if(mAccumulator < mMinSubStepSize)
{
substepCount = 0;
return;
}
substepCount = PxMin(PxU32(PxCeil(mAccumulator/mMaxSubStepSize)), mMaxSubSteps);
substepSize = PxMin(mAccumulator/substepCount, mMaxSubStepSize);
mAccumulator -= PxReal(substepCount)*substepSize;
}
void PxsFluidDynamics::updatePacketLocalHash(PxsSphUpdateType updateType, PxVec3* forceBuf, PxsFluidParticle* particles, const PxsParticleCell& packet,
const PxsFluidPacketSections& packetSections, const PxsFluidPacketHaloRegions& haloRegions,
PxsFluidDynamicsTempBuffers& tempBuffers)
{
// Particle index lists for local hash of particle cells (for two subpackets A and B).
PxU32* particleIndicesSpA = tempBuffers.indicesSubpacketA;
PxU32* particleIndicesSpB = tempBuffers.indicesSubpacketB;
// Local hash tables for particle cells (for two subpackets A and B).
PxsParticleCell* particleCellsSpA = tempBuffers.cellHashTableSubpacketA;
PxsParticleCell* particleCellsSpB = tempBuffers.cellHashTableSubpacketB;
PxVec3 packetCorner = PxVec3(PxReal(packet.coords.x), PxReal(packet.coords.y), PxReal(packet.coords.z)) * mParams.packetSize;
PxU32 particlesLeftA0 = packet.numParticles;
PxsFluidParticle* particlesSpA0 = particles + packet.firstParticle;
PxVec3* forceBufA0 = forceBuf + packet.firstParticle;
while (particlesLeftA0)
{
PxU32 numParticlesSpA = PxMin(particlesLeftA0, static_cast<PxU32>(PXS_FLUID_SUBPACKET_PARTICLE_LIMIT_FORCE_DENSITY));
// Make sure the number of hash buckets is a power of 2 (requirement for the used hash function)
const PxU32 numCellHashBucketsSpA = Ps::nextPowerOfTwo(numParticlesSpA + 1);
PX_ASSERT(numCellHashBucketsSpA <= tempBuffers.cellHashMaxSize);
// Get local cell hash for the current subpacket
PxsFluidSpatialHash::buildLocalHash(particlesSpA0, numParticlesSpA, particleCellsSpA,
particleIndicesSpA, tempBuffers.hashKeys, numCellHashBucketsSpA, mParams.cellSizeInv, packetCorner);
//---------------------------------------------------------------------------------------------------
//
// Compute particle interactions between particles within the current subpacket.
//
updateCellsSubpacket(updateType, forceBufA0, particlesSpA0, particleCellsSpA, particleIndicesSpA, numCellHashBucketsSpA, mParams, tempBuffers);
//---------------------------------------------------------------------------------------------------
//
// Compute particle interactions between particles of current subpacket and particles
// of other subpackets within the same packet (i.e., we process all subpacket pairs).
//
PxU32 particlesLeftB = particlesLeftA0 - numParticlesSpA;
PxsFluidParticle* particlesSpB = particlesSpA0 + numParticlesSpA;
PxVec3* forceBufB = forceBufA0 + numParticlesSpA;
while (particlesLeftB)
{
PxU32 numParticlesSpB = PxMin(particlesLeftB, static_cast<PxU32>(PXS_FLUID_SUBPACKET_PARTICLE_LIMIT_FORCE_DENSITY));
// Make sure the number of hash buckets is a power of 2 (requirement for the used hash function)
const PxU32 numCellHashBucketsSpB = Ps::nextPowerOfTwo(numParticlesSpB + 1);
PX_ASSERT(numCellHashBucketsSpB <= tempBuffers.cellHashMaxSize);
// Get local cell hash for other subpacket
PxsFluidSpatialHash::buildLocalHash(particlesSpB, numParticlesSpB, particleCellsSpB, particleIndicesSpB, tempBuffers.hashKeys,
numCellHashBucketsSpB, mParams.cellSizeInv, packetCorner);
// For the cells of subpacket A, find neighboring cells in the subpacket B and compute particle interactions.
updateCellsSubpacketPair(updateType, forceBufA0, forceBufB, particlesSpA0, particlesSpB, particleCellsSpA, particleCellsSpB,
particleIndicesSpA, particleIndicesSpB, numCellHashBucketsSpA, numCellHashBucketsSpB, true, mParams, tempBuffers, numParticlesSpA < numParticlesSpB);
particlesLeftB -= numParticlesSpB;
particlesSpB += numParticlesSpB;
forceBufB += numParticlesSpB;
}
particlesLeftA0 -= numParticlesSpA;
particlesSpA0 += numParticlesSpA;
forceBufA0 += numParticlesSpA;
}
//---------------------------------------------------------------------------------------------------
//
// Compute particle interactions between particles of sections of the current packet and particles of neighboring
// halo regions
//
PX_ASSERT(PXS_FLUID_BRUTE_FORCE_PARTICLE_THRESHOLD_HALO_VS_SECTION <= PXS_FLUID_SUBPACKET_PARTICLE_LIMIT_FORCE_DENSITY);
if (haloRegions.maxNumParticles != 0)
{
for(PxU32 s=0; s < 26; s++)
{
PxU32 numSectionParticles = packetSections.numParticles[s];
if (numSectionParticles == 0)
continue;
bool sectionEnablesBruteForce = (numSectionParticles <= PXS_FLUID_BRUTE_FORCE_PARTICLE_THRESHOLD_HALO_VS_SECTION);
SectionToHaloTable& neighborHaloRegions = sSectionToHaloTable[s];
PxU32 numHaloNeighbors = neighborHaloRegions.numHaloRegions;
PxU32 particlesLeftA = numSectionParticles;
PxsFluidParticle* particlesSpA = particles + packetSections.firstParticle[s];
PxVec3* forceBufA = forceBuf + packetSections.firstParticle[s];
while (particlesLeftA)
{
PxU32 numParticlesSpA = PxMin(particlesLeftA, static_cast<PxU32>(PXS_FLUID_SUBPACKET_PARTICLE_LIMIT_FORCE_DENSITY));
// Compute particle interactions between particles of the current subpacket (of the section)
// and particles of neighboring halo regions relevant.
//Process halo regions which need local hash building first.
bool isLocalHashValid = false;
// Make sure the number of hash buckets is a power of 2 (requirement for the used hash function)
const PxU32 numCellHashBucketsSpA = Ps::nextPowerOfTwo(numParticlesSpA + 1);
PX_ASSERT(numCellHashBucketsSpA <= tempBuffers.cellHashMaxSize);
#if MERGE_HALO_REGIONS
//Read halo region particles into temporary buffer
PxU32 numMergedHaloParticles = 0;
for(PxU32 h = 0; h < numHaloNeighbors; h++)
{
PxU32 haloRegionIdx = neighborHaloRegions.haloRegionIndices[h];
PxU32 numHaloParticles = haloRegions.numParticles[haloRegionIdx];
// chunk regions into subpackets!
PxU32 particlesLeftB = numHaloParticles;
PxsFluidParticle* particlesSpB = particles + haloRegions.firstParticle[haloRegionIdx];
PxVec3* forceBufB = forceBuf + haloRegions.firstParticle[haloRegionIdx];
while (particlesLeftB)
{
PxU32 numParticlesSpB = PxMin(particlesLeftB, static_cast<PxU32>(PXS_FLUID_SUBPACKET_PARTICLE_LIMIT_FORCE_DENSITY));
// if there are plenty of particles already, don't bother to do the copy for merging.
if (numParticlesSpB > PXS_FLUID_BRUTE_FORCE_PARTICLE_THRESHOLD_HALO_VS_SECTION)
{
updateSubpacketPairHalo(forceBufA, particlesSpA, numParticlesSpA, particleCellsSpA, particleIndicesSpA, isLocalHashValid, numCellHashBucketsSpA,
forceBufB, particlesSpB, numParticlesSpB, particleCellsSpB, particleIndicesSpB, packetCorner, updateType, hashKeyArray, tempBuffers);
}
else
{
if (numMergedHaloParticles + numParticlesSpB > PXS_FLUID_SUBPACKET_PARTICLE_LIMIT_FORCE_DENSITY)
{
//flush
updateSubpacketPairHalo(forceBufA, particlesSpA, numParticlesSpA, particleCellsSpA, particleIndicesSpA, isLocalHashValid, numCellHashBucketsSpA,
tempBuffers.mergedHaloRegions, numMergedHaloParticles, particleCellsSpB, particleIndicesSpB, packetCorner, updateType, hashKeyArray, tempBuffers);
numMergedHaloParticles = 0;
}
for (PxU32 k = 0; k < numParticlesSpB; ++k)
tempBuffers.mergedHaloRegions[numMergedHaloParticles++] = particlesSpB[k];
}
particlesLeftB -= numParticlesSpB;
particlesSpB += numParticlesSpB;
}
}
//flush
updateSubpacketPairHalo(forceBufA, particlesSpA, numParticlesSpA, particleCellsSpA, particleIndicesSpA, isLocalHashValid, numCellHashBucketsSpA,
tempBuffers.mergedHaloRegions, numMergedHaloParticles, particleCellsSpB, particleIndicesSpB, packetCorner, updateType, hashKeyArray, tempBuffers);
#else // MERGE_HALO_REGIONS
for(PxU32 h = 0; h < numHaloNeighbors; h++)
{
PxU32 haloRegionIdx = neighborHaloRegions.haloRegionIndices[h];
PxU32 numHaloParticles = haloRegions.numParticles[haloRegionIdx];
bool haloRegionEnablesBruteForce = (numHaloParticles <= PXS_FLUID_BRUTE_FORCE_PARTICLE_THRESHOLD_HALO_VS_SECTION);
if (sectionEnablesBruteForce && haloRegionEnablesBruteForce)
continue;
if (!isLocalHashValid)
{
// Get local cell hash for the current subpacket
PxsFluidSpatialHash::buildLocalHash(particlesSpA, numParticlesSpA, particleCellsSpA,
particleIndicesSpA, tempBuffers.hashKeys, numCellHashBucketsSpA, mParams.cellSizeInv, packetCorner);
isLocalHashValid = true;
}
PxU32 particlesLeftB = numHaloParticles;
PxsFluidParticle* particlesSpB = particles + haloRegions.firstParticle[haloRegionIdx];
while (particlesLeftB)
{
PxU32 numParticlesSpB = PxMin(particlesLeftB, static_cast<PxU32>(PXS_FLUID_SUBPACKET_PARTICLE_LIMIT_FORCE_DENSITY));
// It is important that no data is written to particles in halo regions since they belong to
// a neighboring packet. The interaction effect of the current packet on the neighboring packet will be
// considered when the neighboring packet is processed.
// Make sure the number of hash buckets is a power of 2 (requirement for the used hash function)
const PxU32 numCellHashBucketsSpB = Ps::nextPowerOfTwo(numParticlesSpB + 1);
PX_ASSERT(numCellHashBucketsSpB <= tempBuffers.cellHashMaxSize);
// Get local cell hash for other subpacket
PxsFluidSpatialHash::buildLocalHash(particlesSpB, numParticlesSpB, particleCellsSpB, particleIndicesSpB, tempBuffers.hashKeys,
numCellHashBucketsSpB, mParams.cellSizeInv, packetCorner);
// For the cells of subpacket A, find neighboring cells in the subpacket B and compute particle interactions.
updateCellsSubpacketPair(updateType, forceBufA, NULL, particlesSpA, particlesSpB, particleCellsSpA, particleCellsSpB,
particleIndicesSpA, particleIndicesSpB, numCellHashBucketsSpA, numCellHashBucketsSpB, false, mParams, tempBuffers, numParticlesSpA > numParticlesSpB);
particlesLeftB -= numParticlesSpB;
particlesSpB += numParticlesSpB;
}
}
//Now process halo regions which don't need local hash building.
PxU32 mergedIndexCount = 0;
for(PxU32 h = 0; h < numHaloNeighbors; h++)
{
PxU32 haloRegionIdx = neighborHaloRegions.haloRegionIndices[h];
PxU32 numHaloParticles = haloRegions.numParticles[haloRegionIdx];
if (numHaloParticles == 0)
continue;
bool haloRegionEnablesBruteForce = (numHaloParticles <= PXS_FLUID_BRUTE_FORCE_PARTICLE_THRESHOLD_HALO_VS_SECTION);
if (!sectionEnablesBruteForce || !haloRegionEnablesBruteForce)
continue;
// The section and the halo region do not have enough particles to make it worth
// building a local cell hash --> use brute force approach
// This is given by the brute force condition (haloRegionEnablesBruteForce). Its necessary to
// make sure a halo region alone fits into the merge buffer.
PX_ASSERT(numHaloParticles <= PXS_FLUID_SUBPACKET_PARTICLE_LIMIT_FORCE_DENSITY);
if (mergedIndexCount + numHaloParticles > PXS_FLUID_SUBPACKET_PARTICLE_LIMIT_FORCE_DENSITY)
{
updateParticleGroupPair(forceBufA, NULL, particlesSpA, particles,
tempBuffers.orderedIndicesSubpacket, numSectionParticles,
tempBuffers.mergedIndices, mergedIndexCount,
false, updateType == PXS_SPH_DENSITY,
mParams, tempBuffers.simdPositionsSubpacket, tempBuffers.indexStream);
mergedIndexCount = 0;
}
PxU32 hpIndex = haloRegions.firstParticle[haloRegionIdx];
for (PxU32 k = 0; k < numHaloParticles; k++)
tempBuffers.mergedIndices[mergedIndexCount++] = hpIndex++;
}
if (mergedIndexCount > 0)
{
updateParticleGroupPair(forceBufA, NULL, particlesSpA, particles,
tempBuffers.orderedIndicesSubpacket, numSectionParticles,
tempBuffers.mergedIndices, mergedIndexCount,
false, updateType == PXS_SPH_DENSITY,
mParams, tempBuffers.simdPositionsSubpacket, tempBuffers.indexStream);
}
#endif // MERGE_HALO_REGIONS
particlesLeftA -= numParticlesSpA;
particlesSpA += numParticlesSpA;
forceBufA += numParticlesSpA;
}
}
}
}
void CreateTerrainGeomtry(LevelGeometry &lg)
{
const int PATCH_SIZE = 64;
if (!Terrain)
return;
PxHeightFieldGeometry g = Terrain->GetHFShape();
const float colScale = g.columnScale;
const float rowScale = g.rowScale;
const float heightScale = g.heightScale;
PxHeightField *physHF = g.heightField;
PxU32 nbCols = physHF->getNbColumns();
PxU32 nbRows = physHF->getNbRows();
PxU32 patchCols = static_cast<PxU32>(ceilf(nbCols / static_cast<float>(PATCH_SIZE)));
PxU32 patchRows = static_cast<PxU32>(ceilf(nbRows / static_cast<float>(PATCH_SIZE)));
lg.meshes.Resize(patchCols * patchRows);
lg.meshStartObjectsIdx = lg.meshes.Count();
for (PxU32 pi = 0; pi < patchCols; ++pi)
{
for (PxU32 pj = 0; pj < patchRows; ++pj)
{
// Fill patch vertices first.
LevelGeometry::Mesh &p = lg.meshes[pi * patchRows + pj];
PxU32 startCol = pi * PATCH_SIZE;
PxU32 startRow = pj * PATCH_SIZE;
PxU32 endCol = (pi + 1) * PATCH_SIZE;
PxU32 endRow = (pj + 1) * PATCH_SIZE;
PxU32 w = std::min(endCol - startCol + 1, nbCols - startCol);
PxU32 h = std::min(endRow - startRow + 1, nbRows - startRow);
p.vertices.Resize(w * h);
for(PxU32 i = 0; i < w; ++i)
{
for(PxU32 j = 0; j < h; ++j)
{
PxReal x = PxReal(i + startCol);
PxReal z = PxReal(j + startRow);
PxReal y = physHF->getHeight(x, z) * heightScale;
PxU32 idx = i * h + j;
p.vertices[idx] = r3dVector(x * colScale, y, z * rowScale);
}
}
// Now triangulate patch
const PxU32 nbFaces = (w - 1) * (h - 1) * 2;
p.indices.Resize(nbFaces * 3);
int * indices = &p.indices.GetFirst();
for (PxU32 i = 0; i < (w - 1); ++i)
{
for (PxU32 j = 0; j < (h - 1); ++j)
{
// first triangle
uint32_t baseIdx = 6 * (i * (h - 1) + j);
indices[baseIdx + 0] = (i + 1) * h + j;
indices[baseIdx + 1] = i * h + j;
indices[baseIdx + 2] = i * h + j + 1;
// second triangle
indices[baseIdx + 3] = (i + 1) * h + j + 1;
indices[baseIdx + 4] = (i + 1) * h + j;
indices[baseIdx + 5] = i * h + j + 1;
}
}
// Filter outside triangles
uint32_t indicesCount = gConvexRegionsManager.FilterOutsideTriangles(&p.vertices.GetFirst(), &p.indices.GetFirst(), p.indices.Count());
p.indices.Resize(indicesCount);
}
}
}
