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Fix PLBVH reduction kernels, simplify nodes per level calculation.

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Also calculate index ranges for each internal node.
This commit is contained in:
Jackson Lee
2014-02-19 21:49:30 -08:00
parent 7f0e361fa0
commit e955192971
4 changed files with 193 additions and 175 deletions
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115
src/Bullet3OpenCL/BroadphaseCollision/kernels/parallelLinearBvh.cl
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@@ -80,60 +80,32 @@ unsigned int getMortonCode(unsigned int x, unsigned int y, unsigned int z)
return interleaveBits(x) << 0 | interleaveBits(y) << 1 | interleaveBits(z) << 2;
}
__kernel void findAllNodesMergedAabb(__global b3AabbCL* out_mergedAabb, int numAabbs)
//Should replace with an optimized parallel reduction
__kernel void findAllNodesMergedAabb(__global b3AabbCL* out_mergedAabb, int numAabbsNeedingMerge)
{
int aabbIndex = get_global_id(0);
if(aabbIndex >= numAabbs) return;
//Find the most significant bit(msb)
int mostSignificantBit = 0;
{
int temp = numAabbs;
while(temp >>= 1) mostSignificantBit++; //Start counting from 0 (0 and 1 have msb 0, 2 has msb 1)
}
int numberOfAabbsAboveMsbSplit = numAabbs & ~( ~(0) << mostSignificantBit );
int numRemainingAabbs = (1 << mostSignificantBit);
//Merge AABBs above most significant bit so that the number of remaining AABBs is a power of 2
//For example, if there are 159 AABBs = 128 + 31, then merge indices [0, 30] and 128 + [0, 30]
if(aabbIndex < numberOfAabbsAboveMsbSplit)
{
int otherAabbIndex = numRemainingAabbs + aabbIndex;
b3AabbCL aabb = out_mergedAabb[aabbIndex];
b3AabbCL otherAabb = out_mergedAabb[otherAabbIndex];
b3AabbCL mergedAabb;
mergedAabb.m_min = b3Min(aabb.m_min, otherAabb.m_min);
mergedAabb.m_max = b3Max(aabb.m_max, otherAabb.m_max);
out_mergedAabb[aabbIndex] = mergedAabb;
}
barrier(CLK_GLOBAL_MEM_FENCE);
//Each time this kernel is added to the command queue,
//the number of AABBs needing to be merged is halved
//
int offset = numRemainingAabbs / 2;
while(offset >= 1)
{
if(aabbIndex < offset)
{
int otherAabbIndex = aabbIndex + offset;
//Example with 159 AABBs:
// numRemainingAabbs == 159 / 2 + 159 % 2 == 80
// numMergedAabbs == 159 - 80 == 79
//So, indices [0, 78] are merged with [0 + 80, 78 + 80]
int numRemainingAabbs = numAabbsNeedingMerge / 2 + numAabbsNeedingMerge % 2;
int numMergedAabbs = numAabbsNeedingMerge - numRemainingAabbs;
int aabbIndex = get_global_id(0);
if(aabbIndex >= numMergedAabbs) return;
int otherAabbIndex = aabbIndex + numRemainingAabbs;
b3AabbCL aabb = out_mergedAabb[aabbIndex];
b3AabbCL otherAabb = out_mergedAabb[otherAabbIndex];
b3AabbCL aabb = out_mergedAabb[aabbIndex];
b3AabbCL otherAabb = out_mergedAabb[otherAabbIndex];
b3AabbCL mergedAabb;
mergedAabb.m_min = b3Min(aabb.m_min, otherAabb.m_min);
mergedAabb.m_max = b3Max(aabb.m_max, otherAabb.m_max);
out_mergedAabb[aabbIndex] = mergedAabb;
}
offset /= 2;
barrier(CLK_GLOBAL_MEM_FENCE);
}
b3AabbCL mergedAabb;
mergedAabb.m_min = b3Min(aabb.m_min, otherAabb.m_min);
mergedAabb.m_max = b3Max(aabb.m_max, otherAabb.m_max);
out_mergedAabb[aabbIndex] = mergedAabb;
}
__kernel void assignMortonCodesAndAabbIndicies(__global b3AabbCL* worldSpaceAabbs, __global b3AabbCL* mergedAabbOfAllNodes,
@@ -254,7 +226,7 @@ __kernel void constructBinaryTree(__global int* firstIndexOffsetPerLevel,
{
int leafNodeLevel = numLevels - 1;
leftChildIndex = (isLeftChildLeaf) ? leftChildIndex - firstIndexOffsetPerLevel[leafNodeLevel] : leftChildIndex;
rightChildIndex = (isLeftChildLeaf) ? rightChildIndex - firstIndexOffsetPerLevel[leafNodeLevel] : rightChildIndex;
rightChildIndex = (isRightChildLeaf) ? rightChildIndex - firstIndexOffsetPerLevel[leafNodeLevel] : rightChildIndex;
}
//Set the negative sign bit if the node is internal
@@ -276,20 +248,19 @@ __kernel void determineInternalNodeAabbs(__global int* firstIndexOffsetPerLevel,
__global int2* internalNodeChildIndices,
__global SortDataCL* mortonCodesAndAabbIndices,
__global b3AabbCL* leafNodeAabbs,
__global b3AabbCL* out_internalNodeAabbs, int numLevels, int numInternalNodes)
__global int2* out_internalNodeLeafIndexRanges,
__global b3AabbCL* out_internalNodeAabbs,
int numLevels, int numInternalNodes, int level)
{
int i = get_global_id(0);
if(i >= numInternalNodes) return;
int numInternalLevels = numLevels - 1;
//Starting from the level next to the leaf nodes, move towards the root(level 0)
for(int level = numInternalLevels - 1; level >= 0; --level)
//For each node in a level, check its child nodes to determine its AABB
{
int indexInLevel = i; //Index relative to firstIndexOffsetPerLevel[level]
int numNodesInLevel = numNodesPerLevel[level];
if(i < numNodesInLevel)
if(indexInLevel < numNodesInLevel)
{
int internalNodeIndexGlobal = indexInLevel + firstIndexOffsetPerLevel[level];
int2 childIndicies = internalNodeChildIndices[internalNodeIndexGlobal];
@@ -300,19 +271,26 @@ __kernel void determineInternalNodeAabbs(__global int* firstIndexOffsetPerLevel,
int isLeftChildLeaf = isLeafNode(childIndicies.x);
int isRightChildLeaf = isLeafNode(childIndicies.y);
//left/RightChildLeafIndex == Rigid body indicies
int leftChildLeafIndex = (isLeftChildLeaf) ? mortonCodesAndAabbIndices[leftChildIndex].m_value : -1;
int rightChildLeafIndex = (isRightChildLeaf) ? mortonCodesAndAabbIndices[rightChildIndex].m_value : -1;
b3AabbCL leftChildAabb = (isLeftChildLeaf) ? leafNodeAabbs[leftChildLeafIndex] : out_internalNodeAabbs[leftChildIndex];
b3AabbCL rightChildAabb = (isRightChildLeaf) ? leafNodeAabbs[rightChildLeafIndex] : out_internalNodeAabbs[rightChildIndex];
//
b3AabbCL internalNodeAabb;
internalNodeAabb.m_min = b3Min(leftChildAabb.m_min, rightChildAabb.m_min);
internalNodeAabb.m_max = b3Max(leftChildAabb.m_max, rightChildAabb.m_max);
out_internalNodeAabbs[internalNodeIndexGlobal] = internalNodeAabb;
//For index range, x == min and y == max; left child always has lower index
int2 leafIndexRange;
leafIndexRange.x = (isLeftChildLeaf) ? leftChildIndex : out_internalNodeLeafIndexRanges[leftChildIndex].x;
leafIndexRange.y = (isRightChildLeaf) ? rightChildIndex : out_internalNodeLeafIndexRanges[rightChildIndex].y;
out_internalNodeLeafIndexRanges[internalNodeIndexGlobal] = leafIndexRange;
}
barrier(CLK_GLOBAL_MEM_FENCE);
}
}
@@ -331,7 +309,9 @@ bool TestAabbAgainstAabb2(const b3AabbCL* aabb1, const b3AabbCL* aabb2)
//From sap.cl
__kernel void plbvhCalculateOverlappingPairs(__global b3AabbCL* rigidAabbs,
__global int2* internalNodeChildIndices, __global b3AabbCL* internalNodeAabbs,
__global int2* internalNodeChildIndices,
__global b3AabbCL* internalNodeAabbs,
__global int2* internalNodeLeafIndexRanges,
__global SortDataCL* mortonCodesAndAabbIndices,
__global int* out_numPairs, __global int4* out_overlappingPairs,
int maxPairs, int numQueryAabbs)
@@ -341,7 +321,8 @@ __kernel void plbvhCalculateOverlappingPairs(__global b3AabbCL* rigidAabbs,
int queryRigidIndex = get_group_id(0) * get_local_size(0) + get_local_id(0);
if(queryRigidIndex >= numQueryAabbs) return;
queryRigidIndex = mortonCodesAndAabbIndices[queryRigidIndex].m_value;
int queryBvhNodeIndex = queryRigidIndex;
queryRigidIndex = mortonCodesAndAabbIndices[queryRigidIndex].m_value; // fix queryRigidIndex naming for this branch
#else
int queryRigidIndex = get_global_id(0);
if(queryRigidIndex >= numQueryAabbs) return;
@@ -363,7 +344,15 @@ __kernel void plbvhCalculateOverlappingPairs(__global b3AabbCL* rigidAabbs,
int isLeaf = isLeafNode(internalOrLeafNodeIndex); //Internal node if false
int bvhNodeIndex = getIndexWithInternalNodeMarkerRemoved(internalOrLeafNodeIndex);
//Optimization - if the node is not a leaf, check whether the highest leaf index of that node
//is less than the queried node's index to avoid testing each pair twice.
{
// fix: produces duplicate pairs
// int highestLeafIndex = (isLeaf) ? numQueryAabbs : internalNodeLeafIndexRanges[bvhNodeIndex].y;
// if(highestLeafIndex < queryBvhNodeIndex) continue;
}
//bvhRigidIndex is not used if internal node
int bvhRigidIndex = (isLeaf) ? mortonCodesAndAabbIndices[bvhNodeIndex].m_value : -1;