void BVH4BuilderFast::build_sequential(size_t threadIndex, size_t threadCount)
{
/* start measurement */
double t0 = 0.0f;
if (g_verbose >= 2) t0 = getSeconds();
/* initialize node and leaf allocator */
nodeAllocator.reset();
primAllocator.reset();
__aligned(64) Allocator nodeAlloc(nodeAllocator);
__aligned(64) Allocator leafAlloc(primAllocator);
/* create prim refs */
global_bounds.reset();
computePrimRefs(0,1);
bvh->bounds = global_bounds.geometry;
/* create initial build record */
BuildRecord br;
br.init(global_bounds,0,numPrimitives);
br.depth = 1;
br.parentNode = (size_t)&bvh->root;
/* build BVH in single thread */
recurseSAH(br,nodeAlloc,leafAlloc,RECURSE_SEQUENTIAL,threadIndex,threadCount);
/* stop measurement */
if (g_verbose >= 2) dt = getSeconds()-t0;
}
bool BVH4BuilderFast::splitParallel(BuildRecord ¤t, BuildRecord &leftChild, BuildRecord &rightChild, const size_t threadID, const size_t numThreads)
{
const unsigned int items = current.end - current.begin;
assert(items >= BUILD_RECORD_SPLIT_THRESHOLD);
/* mark as leaf if leaf threshold reached */
if (items <= QBVH_BUILDER_LEAF_ITEM_THRESHOLD) {
current.createLeaf();
return false;
}
/* use primitive array temporarily for parallel splits */
PrimRef* tmp = (PrimRef*) primAllocator.base();
/* parallel binning of centroids */
g_state->parallelBinner.bin(current,prims,tmp,threadID,numThreads);
/* find best split */
Split split;
g_state->parallelBinner.best(split);
/* if we cannot find a valid split, enforce an arbitrary split */
if (unlikely(split.pos == -1)) split_fallback(prims,current,leftChild,rightChild);
/* parallel partitioning of items */
else g_state->parallelBinner.partition(tmp,prims,split,leftChild,rightChild,threadID,numThreads);
if (leftChild.items() <= QBVH_BUILDER_LEAF_ITEM_THRESHOLD) leftChild.createLeaf();
if (rightChild.items() <= QBVH_BUILDER_LEAF_ITEM_THRESHOLD) rightChild.createLeaf();
return true;
}
void BVH4Triangle4vBuilderFast::createSmallLeaf(BuildRecord& current, Allocator& leafAlloc, size_t threadID)
{
size_t items = current.size();
size_t start = current.begin;
assert(items<=4);
/* allocate leaf node */
Triangle4v* accel = (Triangle4v*) leafAlloc.malloc(sizeof(Triangle4v));
*current.parent = bvh->encodeLeaf((char*)accel,1);
ssei vgeomID = -1, vprimID = -1, vmask = -1;
sse3f v0 = zero, v1 = zero, v2 = zero;
for (size_t i=0; i<items; i++)
{
const size_t geomID = prims[start+i].geomID();
const size_t primID = prims[start+i].primID();
const TriangleMesh* __restrict__ const mesh = scene->getTriangleMesh(geomID);
const TriangleMesh::Triangle& tri = mesh->triangle(primID);
const Vec3fa& p0 = mesh->vertex(tri.v[0]);
const Vec3fa& p1 = mesh->vertex(tri.v[1]);
const Vec3fa& p2 = mesh->vertex(tri.v[2]);
vgeomID [i] = geomID;
vprimID [i] = primID;
vmask [i] = mesh->mask;
v0.x[i] = p0.x; v0.y[i] = p0.y; v0.z[i] = p0.z;
v1.x[i] = p1.x; v1.y[i] = p1.y; v1.z[i] = p1.z;
v2.x[i] = p2.x; v2.y[i] = p2.y; v2.z[i] = p2.z;
}
Triangle4v::store_nt(accel,Triangle4v(v0,v1,v2,vgeomID,vprimID,vmask));
}
void BVH4Triangle1vBuilderFast::createSmallLeaf(BuildRecord& current, Allocator& leafAlloc, size_t threadID)
{
size_t items = current.size();
size_t start = current.begin;
assert(items<=4);
/* allocate leaf node */
Triangle1v* accel = (Triangle1v*) leafAlloc.malloc(items*sizeof(Triangle1v));
*current.parent = bvh->encodeLeaf((char*)accel,items);
for (size_t i=0; i<items; i++)
{
const size_t geomID = prims[start+i].geomID();
const size_t primID = prims[start+i].primID();
const TriangleMesh* __restrict__ const mesh = scene->getTriangleMesh(geomID);
const TriangleMesh::Triangle& tri = mesh->triangle(primID);
const ssef v0 = select(0x7,(ssef)mesh->vertex(tri.v[0]),zero);
const ssef v1 = select(0x7,(ssef)mesh->vertex(tri.v[1]),zero);
const ssef v2 = select(0x7,(ssef)mesh->vertex(tri.v[2]),zero);
const ssef e1 = v0 - v1;
const ssef e2 = v2 - v0;
const ssef normal = cross(e1,e2);
store4f_nt(&accel[i].v0,cast(insert<3>(cast(v0),primID)));
store4f_nt(&accel[i].v1,cast(insert<3>(cast(v1),geomID)));
store4f_nt(&accel[i].v2,cast(insert<3>(cast(v2),mesh->mask)));
}
}
__forceinline void BVH4BuilderTopLevel::split(BuildRecord& current, BuildRecord& left, BuildRecord& right, const size_t mode, const size_t threadID, const size_t numThreads)
{
if (mode == BUILD_TOP_LEVEL && current.items() >= BUILD_RECORD_SPLIT_THRESHOLD)
return split_parallel(current,left,right,threadID,numThreads);
else
return split_sequential(current,left,right);
}
__forceinline void BVH4BuilderTopLevel::recurse(size_t depth, BuildRecord& current, const size_t mode, const size_t threadID, const size_t numThreads)
{
if (mode == BUILD_TOP_LEVEL) {
g_state->global_workStack.push_nolock(current);
}
else if (current.items() > THRESHOLD_FOR_SUBTREE_RECURSION) {
if (!g_state->thread_workStack[threadID].push(current))
recurseSAH(depth,current,RECURSE,threadID,numThreads);
}
else
recurseSAH(depth,current,RECURSE,threadID,numThreads);
}
__forceinline void BVH4BuilderFast::recurse(BuildRecord& current, Allocator& nodeAlloc, Allocator& leafAlloc, const size_t mode, const size_t threadID, const size_t numThreads)
{
if (mode == BUILD_TOP_LEVEL) {
g_state->workStack.push_nolock(current);
}
else if (mode == RECURSE_PARALLEL && current.items() > THRESHOLD_FOR_SUBTREE_RECURSION) {
if (!g_state->threadStack[threadID].push(current))
recurseSAH(current,nodeAlloc,leafAlloc,RECURSE_SEQUENTIAL,threadID,numThreads);
}
else
recurseSAH(current,nodeAlloc,leafAlloc,mode,threadID,numThreads);
}
bool BVH4BuilderFast::splitSequential(BuildRecord& current, BuildRecord& leftChild, BuildRecord& rightChild)
{
/* mark as leaf if leaf threshold reached */
if (current.items() <= QBVH_BUILDER_LEAF_ITEM_THRESHOLD) {
current.createLeaf();
return false;
}
/* calculate binning function */
Mapping<16> mapping(current.bounds);
/* binning of centroids */
Binner<16> binner;
binner.bin(prims,current.begin,current.end,mapping);
/* find best split */
Split split;
binner.best(split,mapping);
/* if we cannot find a valid split, enforce an arbitrary split */
if (unlikely(split.pos == -1)) split_fallback(prims,current,leftChild,rightChild);
/* partitioning of items */
else binner.partition(prims, current.begin, current.end, split, mapping, leftChild, rightChild);
if (leftChild.items() <= QBVH_BUILDER_LEAF_ITEM_THRESHOLD) leftChild.createLeaf();
if (rightChild.items() <= QBVH_BUILDER_LEAF_ITEM_THRESHOLD) rightChild.createLeaf();
return true;
}
void BVH4UserGeometryBuilderFast::createSmallLeaf(BuildRecord& current, Allocator& leafAlloc, size_t threadID)
{
size_t items = current.size();
size_t start = current.begin;
/* allocate leaf node */
AccelSetItem* accel = (AccelSetItem*) leafAlloc.malloc(sizeof(AccelSetItem)*items);
*current.parent = bvh->encodeLeaf(accel,items);
for (size_t i=0; i<items; i++)
{
const PrimRef& prim = prims[start+i];
accel[i].accel = (AccelSet*) (UserGeometryBase*) scene->get(prim.geomID()); //(*accels)[prim.geomID()];
accel[i].item = prim.primID();
}
}
void BVH4Bezier1iBuilderFast::createSmallLeaf(BuildRecord& current, Allocator& leafAlloc, size_t threadID)
{
size_t items = current.size();
size_t start = current.begin;
/* allocate leaf node */
Bezier1i* accel = (Bezier1i*) leafAlloc.malloc(items*sizeof(Bezier1i));
*current.parent = bvh->encodeLeaf((char*)accel,items);
for (size_t i=0; i<items; i++)
{
const size_t geomID = prims[start+i].geomID();
const size_t primID = prims[start+i].primID();
const BezierCurves* curves = scene->getBezierCurves(geomID);
const Vec3fa& p0 = curves->vertex(curves->curve(primID));
new (&accel[i]) Bezier1i(&p0,geomID,primID);
}
}
void BVH4Triangle4iBuilderFast::createSmallLeaf(BuildRecord& current, Allocator& leafAlloc, size_t threadID)
{
size_t items = current.size();
size_t start = current.begin;
assert(items<=4);
/* allocate leaf node */
Triangle4i* accel = (Triangle4i*) leafAlloc.malloc(sizeof(Triangle4i));
*current.parent = bvh->encodeLeaf((char*)accel,1);
ssei geomID = -1, primID = -1;
Vec3f* v0[4] = { NULL, NULL, NULL, NULL };
ssei v1 = zero, v2 = zero;
for (size_t i=0; i<items; i++)
{
const PrimRef& prim = prims[start+i];
const TriangleMesh* mesh = scene->getTriangleMesh(prim.geomID());
const TriangleMesh::Triangle& tri = mesh->triangle(prim.primID());
geomID[i] = prim.geomID();
primID[i] = prim.primID();
v0[i] = (Vec3f*) &mesh->vertex(tri.v[0]);
v1[i] = (int*)&mesh->vertex(tri.v[1])-(int*)v0[i];
v2[i] = (int*)&mesh->vertex(tri.v[2])-(int*)v0[i];
}
for (size_t i=items; i<4; i++)
{
geomID[i] = -1;
primID[i] = -1;
v0[i] = v0[0];
v1[i] = 0;
v2[i] = 0;
}
new (accel) Triangle4i(v0,v1,v2,geomID,primID);
}
void BVH4BuilderFast::createLeaf(BuildRecord& current, Allocator& nodeAlloc, Allocator& leafAlloc, size_t threadIndex, size_t threadCount)
{
#if defined(DEBUG)
if (current.depth > BVH4::maxBuildDepthLeaf)
throw std::runtime_error("ERROR: depth limit reached");
#endif
/* create leaf for few primitives */
if (current.items() <= QBVH_BUILDER_LEAF_ITEM_THRESHOLD) {
createSmallLeaf(this,current,leafAlloc,threadIndex);
return;
}
/* first split level */
BuildRecord record0, record1;
split_fallback(prims,current,record0,record1);
/* second split level */
BuildRecord children[4];
split_fallback(prims,record0,children[0],children[1]);
split_fallback(prims,record1,children[2],children[3]);
/* allocate node */
Node* node = (Node*) nodeAlloc.malloc(sizeof(Node)); node->clear();
*(NodeRef*)current.parentNode = bvh->encodeNode(node);
/* recurse into each child */
for (size_t i=0; i<4; i++)
{
node->set(i,children[i].bounds.geometry);
children[i].parentNode = (size_t)&node->child(i);
children[i].depth = current.depth+1;
createLeaf(children[i],nodeAlloc,leafAlloc,threadIndex,threadCount);
}
BVH4::compact(node); // move empty nodes to the end
}
void BVH4BuilderTopLevel::build_toplevel(size_t threadIndex, size_t threadCount)
{
/* calculate scene bounds */
Centroid_Scene_AABB bounds; bounds.reset();
for (size_t i=0; i<threadCount; i++)
bounds.extend(g_state->thread_bounds[i]);
/* ignore empty scenes */
//bvh->clear();
bvh->bounds = bounds.geometry;
refs.resize(nextRef);
if (refs.size() == 0) return;
double t0 = 0.0;
if (g_verbose >= 2) {
std::cout << "building BVH4<" << bvh->primTy.name << "> with toplevel SAH builder ... " << std::flush;
t0 = getSeconds();
}
/* open all large nodes */
#if 0
open_sequential();
refs1.resize(refs.size());
#else
global_dest = refs.size();
size_t M = max(size_t(2*global_dest),size_t(MIN_OPEN_SIZE));
refs .resize(M);
refs1.resize(M);
barrier.init(threadCount);
TaskScheduler::executeTask(threadIndex,threadCount,_task_open_parallel,this,threadCount,"toplevel_open_parallel");
refs.resize(global_dest);
#endif
bvh->init(refs.size());
/* start toplevel build */
BuildRecord task;
task.init(bounds,0,refs.size());
task.parentNode = (size_t)&bvh->root;
task.depth = 1;
/* initialize thread-local work stacks */
for (size_t i=0; i<threadCount; i++)
g_state->thread_workStack[i].reset();
/* push initial build record to global work stack */
g_state->global_workStack.reset();
g_state->global_workStack.push_nolock(task);
/* work in multithreaded toplevel mode until sufficient subtasks got generated */
while (g_state->global_workStack.size() < 4*threadCount && g_state->global_workStack.size()+BVH4::N <= SIZE_WORK_STACK)
{
BuildRecord br;
if (!g_state->global_workStack.pop_nolock_largest(br)) break;
recurseSAH(0,br,BUILD_TOP_LEVEL,threadIndex,threadCount);
}
/* now process all created subtasks on multiple threads */
TaskScheduler::executeTask(threadIndex,threadCount,_task_build_subtrees,this,threadCount,"toplevel_build_subtrees");
if (g_verbose >= 2) {
double t1 = getSeconds();
std::cout << "[DONE]" << std::endl;
std::cout << " dt = " << 1000.0f*(t1-t0) << "ms" << std::endl;
std::cout << BVH4Statistics(bvh).str();
}
}
void BVH4BuilderFast::build_parallel(size_t threadIndex, size_t threadCount, size_t taskIndex, size_t taskCount, TaskScheduler::Event* event)
{
/* wait for all threads to enter */
g_state->barrier.wait(threadIndex,threadCount);
/* start measurement */
double t0 = 0.0f;
if (g_verbose >= 2) t0 = getSeconds();
/* all worker threads enter tasking system */
if (threadIndex != 0) {
g_state->scheduler.dispatchTaskMainLoop(threadIndex,threadCount);
return;
}
/* calculate list of primrefs */
global_bounds.reset();
g_state->scheduler.dispatchTask( task_computePrimRefs, this, threadIndex, threadCount );
bvh->bounds = global_bounds.geometry;
/* initialize node and leaf allocator */
nodeAllocator.reset();
primAllocator.reset();
__aligned(64) Allocator nodeAlloc(nodeAllocator);
__aligned(64) Allocator leafAlloc(primAllocator);
/* create initial build record */
BuildRecord br;
br.init(global_bounds,0,numPrimitives);
br.depth = 1;
br.parentNode = (size_t)&bvh->root;
/* initialize thread-local work stacks */
for (size_t i=0; i<threadCount; i++)
g_state->threadStack[i].reset();
/* push initial build record to global work stack */
g_state->workStack.reset();
g_state->workStack.push_nolock(br);
/* work in multithreaded toplevel mode until sufficient subtasks got generated */
while (g_state->workStack.size() < 4*threadCount && g_state->workStack.size()+BVH4::N <= SIZE_WORK_STACK)
{
BuildRecord br;
/* pop largest item for better load balancing */
if (!g_state->workStack.pop_nolock_largest(br))
break;
/* guarantees to create no leaves in this stage */
if (br.items() <= QBVH_BUILDER_LEAF_ITEM_THRESHOLD)
break;
recurseSAH(br,nodeAlloc,leafAlloc,BUILD_TOP_LEVEL,threadIndex,threadCount);
}
/* now process all created subtasks on multiple threads */
g_state->scheduler.dispatchTask(task_buildSubTrees, this, threadIndex, threadCount );
/* release all threads again */
g_state->scheduler.releaseThreads(threadCount);
/* stop measurement */
if (g_verbose >= 2) dt = getSeconds()-t0;
}
void BVH4BuilderFast::recurseSAH(BuildRecord& current, Allocator& nodeAlloc, Allocator& leafAlloc, const size_t mode, const size_t threadID, const size_t numThreads)
{
__aligned(64) BuildRecord children[BVH4::N];
/* create leaf node */
if (current.depth >= BVH4::maxBuildDepth || current.isLeaf()) {
assert(mode != BUILD_TOP_LEVEL);
createLeaf(current,nodeAlloc,leafAlloc,threadID,numThreads);
return;
}
/* fill all 4 children by always splitting the one with the largest surface area */
unsigned int numChildren = 1;
children[0] = current;
do {
/* find best child with largest bounding box area */
int bestChild = -1;
float bestArea = neg_inf;
for (unsigned int i=0; i<numChildren; i++)
{
/* ignore leaves as they cannot get split */
if (children[i].isLeaf())
continue;
/* remember child with largest area */
if (children[i].sceneArea() > bestArea) {
bestArea = children[i].sceneArea();
bestChild = i;
}
}
if (bestChild == -1) break;
/*! split best child into left and right child */
__aligned(64) BuildRecord left, right;
if (!split(children[bestChild],left,right,mode,threadID,numThreads))
continue;
/* add new children left and right */
left.depth = right.depth = current.depth+1;
children[bestChild] = children[numChildren-1];
children[numChildren-1] = left;
children[numChildren+0] = right;
numChildren++;
} while (numChildren < BVH4::N);
/* create leaf node if no split is possible */
if (numChildren == 1) {
assert(mode != BUILD_TOP_LEVEL);
createLeaf(current,nodeAlloc,leafAlloc,threadID,numThreads);
return;
}
/* allocate node */
Node* node = (Node*) nodeAlloc.malloc(sizeof(Node)); node->clear();
*(NodeRef*)current.parentNode = bvh->encodeNode(node);
/* recurse into each child */
for (unsigned int i=0; i<numChildren; i++)
{
node->set(i,children[i].bounds.geometry);
children[i].parentNode = (size_t)&node->child(i);
children[i].depth = current.depth+1;
recurse(children[i],nodeAlloc,leafAlloc,mode,threadID,numThreads);
}
}
