_xiaofang/xiaofang/Assets/Obi/Resources/Compute/SpatialQueries.compute
杨号敬 bcc74f0465 add
2024-12-18 02:18:45 +08:00

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#include "GridUtils.cginc"
#include "CollisionMaterial.cginc"
#include "ContactHandling.cginc"
#include "ColliderDefinitions.cginc"
#include "Rigidbody.cginc"
#include "Bounds.cginc"
#include "Simplex.cginc"
#include "SolverParameters.cginc"
#include "AtomicDeltas.cginc"
#include "Phases.cginc"
#include "QueryDefinitions.cginc"
#define MAX_RESULTS_PER_SIMPLEX 32
#pragma kernel Clear
#pragma kernel BuildUnsortedList
#pragma kernel FindPopulatedLevels
#pragma kernel SortList
#pragma kernel BuildContactList
#pragma kernel PrefixSumColliderCounts
#pragma kernel SortContactPairs
StructuredBuffer<float4> positions;
StructuredBuffer<quaternion> orientations;
StructuredBuffer<float4> principalRadii;
StructuredBuffer<int> activeParticles;
StructuredBuffer<int> simplices;
StructuredBuffer<int> filters;
RWStructuredBuffer<aabb> simplexBounds; // bounding box of each simplex.
StructuredBuffer<transform> transforms;
StructuredBuffer<queryShape> shapes;
RWStructuredBuffer<uint> sortedColliderIndices;
RWStructuredBuffer<uint> colliderTypeCounts;
RWStructuredBuffer<uint> contactOffsetsPerType;
RWStructuredBuffer<uint2> unsortedContactPairs;
RWStructuredBuffer<uint> cellIndices;
RWStructuredBuffer<uint> cellOffsets;
RWStructuredBuffer<uint> cellCounts;
RWStructuredBuffer<uint> offsetInCells;
RWStructuredBuffer<contact> contacts;
RWStructuredBuffer<uint2> contactPairs;
RWStructuredBuffer<uint> dispatchBuffer;
StructuredBuffer<transform> solverToWorld;
StructuredBuffer<transform> worldToSolver;
uint maxResults;
uint queryCount; // amount of colliders in the grid.
uint cellsPerShape; // max amount of cells a collider can be inserted into. Typically this is 8.
int shapeTypeCount; // number of different query shapes, ie: box, sphere, ray, etc.
aabb CalculateShapeAABB(in queryShape shape)
{
float offset = shape.contactOffset + shape.maxDistance;
aabb bounds;
bounds.min_ = FLT_MAX;
bounds.max_ = FLT_MIN;
switch (shape.type)
{
case SPHERE_QUERY:
bounds.FromParticle(shape.center, shape.size.x + offset); break;
case BOX_QUERY:
bounds.FromEdge(shape.center - shape.size*0.5f, shape.center + shape.size * 0.5f, offset); break;
case RAY_QUERY:
bounds.FromEdge(shape.center, shape.center + shape.size, offset); break;
}
return bounds;
}
[numthreads(128, 1, 1)]
void Clear (uint3 id : SV_DispatchThreadID)
{
unsigned int i = id.x;
if (i == 0)
{
for (int l = 0; l <= GRID_LEVELS; ++l)
levelPopulation[l] = 0;
}
// clear all cell offsets to invalid, so that we can later use atomic minimum to calculate the offset.
if (i < maxCells)
{
cellOffsets[i] = INVALID;
cellCounts[i] = 0;
}
// clear all cell indices to invalid.
if (i < queryCount)
{
for (uint j = 0; j < cellsPerShape; ++j)
cellIndices[i*cellsPerShape+j] = INVALID;
}
}
[numthreads(128, 1, 1)]
void BuildUnsortedList (uint3 id : SV_DispatchThreadID)
{
unsigned int i = id.x;
if (i >= queryCount) return;
// get bounds in solver space:
aabb bounds = CalculateShapeAABB(shapes[i]).Transformed(worldToSolver[0].Multiply(transforms[i]));
// calculate bounds size, grid level and cell size:
float4 size = bounds.max_ - bounds.min_;
float maxSize = max(max (size.x, size.y), size.z);
int level = GridLevelForSize(maxSize);
float cellSize = CellSizeOfLevel(level);
// calculate max and min cell coordinates (force 4th component to zero, might not be after expanding)
int4 minCell = floor(bounds.min_ / cellSize);
int4 maxCell = floor(bounds.max_ / cellSize);
minCell[3] = 0;
maxCell[3] = 0;
int4 cellSpan = maxCell - minCell;
// insert collider in cells:
for (int x = 0; x <= cellSpan[0]; ++x)
{
for (int y = 0; y <= cellSpan[1]; ++y)
{
for (int z = 0; z <= cellSpan[2]; ++z)
{
int cellIndex = GridHash(minCell + int4(x, y, z, level));
// calculate flat index of this cell into arrays:
int k = x + y*2 + z*4 + i*cellsPerShape;
cellIndices[k] = cellIndex;
InterlockedAdd(cellCounts[cellIndex],1,offsetInCells[k]);
}
}
}
// atomically increase this level's population by one:
InterlockedAdd(levelPopulation[1 + level],1);
}
[numthreads(128, 1, 1)]
void SortList (uint3 id : SV_DispatchThreadID)
{
uint i = id.x;
if (i >= queryCount * cellsPerShape) return;
uint cellIndex = cellIndices[i];
if (cellIndex != INVALID)
{
// write shape to its sorted index:
uint sortedIndex = cellOffsets[cellIndex] + offsetInCells[i];
sortedColliderIndices[sortedIndex] = i;
}
}
[numthreads(128, 1, 1)]
void BuildContactList (uint3 id : SV_DispatchThreadID)
{
unsigned int threadIndex = id.x;
if (threadIndex >= pointCount + edgeCount + triangleCount) return;
uint cellCount = queryCount * cellsPerShape;
int candidateCount = 0;
uint candidates[MAX_RESULTS_PER_SIMPLEX];
int simplexSize;
int simplexStart = GetSimplexStartAndSize(threadIndex, simplexSize);
aabb b = simplexBounds[threadIndex];
// max size of the particle bounds in cells:
int4 maxSize = int4(10,10,10,10);
// build a list of candidate colliders:
for (uint m = 1; m <= levelPopulation[0]; ++m)
{
uint l = levelPopulation[m];
float cellSize = CellSizeOfLevel(l);
int4 minCell = floor(b.min_ / cellSize);
int4 maxCell = floor(b.max_ / cellSize);
maxCell = minCell + min(maxCell - minCell, maxSize);
for (int x = minCell[0]; x <= maxCell[0]; ++x)
{
for (int y = minCell[1]; y <= maxCell[1]; ++y)
{
for (int z = minCell[2]; z <= maxCell[2]; ++z)
{
uint flatCellIndex = GridHash(int4(x,y,z,l));
uint cellStart = cellOffsets[flatCellIndex];
uint cellCount = cellCounts[flatCellIndex];
// iterate through queries in the neighbour cell
for (uint n = cellStart; n < cellStart + cellCount; ++n)
{
if (candidateCount < MAX_RESULTS_PER_SIMPLEX)
candidates[candidateCount++] = sortedColliderIndices[n] / cellsPerShape;
}
}
}
}
}
//evaluate candidates and create contacts:
if (candidateCount > 0)
{
// insert sort:
for (int k = 1; k < candidateCount; ++k)
{
uint key = candidates[k];
int j = k - 1;
while (j >= 0 && candidates[j] > key)
candidates[j + 1] = candidates[j--];
candidates[j + 1] = key;
}
// make sure each candidate only shows up once in the list:
int first = 0, contactCount = 0;
while(++first != candidateCount)
{
if (candidates[contactCount] != candidates[first])
candidates[++contactCount] = candidates[first];
}
contactCount++;
// append contacts:
for (int i = 0; i < contactCount; i++)
{
int c = candidates[i];
// get shape bounds in solver space:
aabb colliderBoundsSS = CalculateShapeAABB(shapes[c]).Transformed(worldToSolver[0].Multiply(transforms[c]));
// check if any simplex particle and the collider should collide:
bool shouldCollide = false;
int colliderCategory = shapes[c].filter & CategoryMask;
int colliderMask = (shapes[c].filter & MaskMask) >> 16;
for (int j = 0; j < simplexSize; ++j)
{
int simplexCategory = filters[simplices[simplexStart + j]] & CategoryMask;
int simplexMask = (filters[simplices[simplexStart + j]] & MaskMask) >> 16;
shouldCollide = shouldCollide || ((simplexCategory & colliderMask) != 0 && (simplexMask & colliderCategory) != 0);
}
if (shouldCollide && b.IntersectsAabb(colliderBoundsSS))
{
uint count;
InterlockedAdd(dispatchBuffer[7], 1, count);
// technically incorrect, as number of pairs != number of contacts but
// we will ignore either excess pairs or contacts.
if (count < maxResults)
{
// increment the amount of contacts for this shape type:
InterlockedAdd(colliderTypeCounts[shapes[c].type],1);
// enqueue a new contact pair:
unsortedContactPairs[count] = uint2(threadIndex,c);
InterlockedMax(dispatchBuffer[4],(count + 1) / 128 + 1);
}
}
}
}
}
[numthreads(1, 1, 1)]
void PrefixSumColliderCounts (uint3 id : SV_DispatchThreadID)
{
contactOffsetsPerType[0] = 0;
int i;
for (i = 0; i < shapeTypeCount; ++i)
{
contactOffsetsPerType[i+1] = contactOffsetsPerType[i] + colliderTypeCounts[i];
// write amount of pairs per collider type in the dispatch buffer:
dispatchBuffer[8 + i*4] = colliderTypeCounts[i] / 128 + 1;
dispatchBuffer[8 + i*4 + 3] = colliderTypeCounts[i];
}
}
[numthreads(128, 1, 1)]
void SortContactPairs (uint3 id : SV_DispatchThreadID)
{
uint i = id.x;
if (i >= dispatchBuffer[7] || i >= maxResults) return;
uint2 pair = unsortedContactPairs[i];
int shapeType = (int)shapes[pair.y].type;
// decrement amount of pairs for the given collider type:
uint count;
InterlockedAdd(colliderTypeCounts[shapeType],-1, count);
// write the pair directly at its position in the sorted array:
contactPairs[contactOffsetsPerType[shapeType] + count - 1] = pair;
}