void BVH4BuilderTopLevel::build(size_t threadIndex, size_t threadCount)
{
/* delete some objects */
size_t N = scene->size();
for (size_t i=N; i<objects.size(); i++) {
delete builders[i]; builders[i] = NULL;
delete objects[i]; objects[i] = NULL;
}
/* resize object array if scene got larger */
if (objects.size() < N) {
objects.resize(N);
builders.resize(N);
}
refs.resize(N);
nextRef = 0;
/* sequential create of acceleration structures */
for (size_t i=0; i<N; i++)
create_object(i);
/* parallel build of acceleration structures */
if (N) scheduler->dispatchTask(threadIndex,threadCount,_task_build_parallel,this,N,"toplevel_build_parallel");
/* perform builds that need all threads */
for (size_t i=0; i<allThreadBuilds.size(); i++) {
build(threadIndex,threadCount,allThreadBuilds[i]);
}
allThreadBuilds.clear();
/* ignore empty scenes */
refs.resize(nextRef);
double t0 = 0.0;
if (g_verbose >= 2) {
std::cout << "building BVH4<" << bvh->primTy.name << "> with " << TOSTRING(isa) << "::TopLevel SAH builder ... " << std::flush;
t0 = getSeconds();
}
/* open all large nodes */
open_sequential();
prims.resize(refs.size());
for (size_t i=0; i<refs.size(); i++) {
prims[i] = PrimRef(refs[i].bounds(),(size_t)refs[i].node);
}
BVH4TopLevelBuilderFastT::build(threadIndex,threadCount,prims.begin(),prims.size());
}
void BVH4BuilderTwoLevel::build(size_t threadIndex, size_t threadCount)
{
/* delete some objects */
size_t N = scene->size();
if (N < objects.size()) {
parallel_for(N, objects.size(), [&] (const range<size_t>& r) {
for (size_t i=r.begin(); i<r.end(); i++) {
delete builders[i]; builders[i] = nullptr;
delete objects[i]; objects[i] = nullptr;
}
});
}
/* reset memory allocator */
bvh->alloc.reset();
/* skip build for empty scene */
const size_t numPrimitives = scene->getNumPrimitives<TriangleMesh,1>();
if (numPrimitives == 0) {
prims.resize(0);
bvh->set(BVH4::emptyNode,empty,0);
return;
}
double t0 = bvh->preBuild(TOSTRING(isa) "::BVH4BuilderTwoLevel");
#if PROFILE
profile(2,20,numPrimitives,[&] (ProfileTimer& timer)
{
#endif
/* resize object array if scene got larger */
if (objects.size() < N) objects.resize(N);
if (builders.size() < N) builders.resize(N);
if (refs.size() < N) refs.resize(N);
nextRef = 0;
/* create of acceleration structures */
parallel_for(size_t(0), N, [&] (const range<size_t>& r)
{
for (size_t objectID=r.begin(); objectID<r.end(); objectID++)
{
TriangleMesh* mesh = scene->getTriangleMeshSafe(objectID);
/* verify meshes got deleted properly */
if (mesh == nullptr || mesh->numTimeSteps != 1) {
assert(objectID < objects.size () && objects[objectID] == nullptr);
assert(objectID < builders.size() && builders[objectID] == nullptr);
continue;
}
/* create BVH and builder for new meshes */
if (objects[objectID] == nullptr)
createTriangleMeshAccel(mesh,(AccelData*&)objects[objectID],builders[objectID]);
}
});
/* parallel build of acceleration structures */
parallel_for(size_t(0), N, [&] (const range<size_t>& r)
{
for (size_t objectID=r.begin(); objectID<r.end(); objectID++)
{
/* ignore if no triangle mesh or not enabled */
TriangleMesh* mesh = scene->getTriangleMeshSafe(objectID);
if (mesh == nullptr || !mesh->isEnabled() || mesh->numTimeSteps != 1)
continue;
BVH4* object = objects [objectID]; assert(object);
Builder* builder = builders[objectID]; assert(builder);
/* build object if it got modified */
#if !PROFILE
if (mesh->isModified())
#endif
builder->build(0,0);
/* create build primitive */
if (!object->bounds.empty())
refs[nextRef++] = BVH4BuilderTwoLevel::BuildRef(object->bounds,object->root);
}
});
/* fast path for single geometry scenes */
if (nextRef == 1) {
bvh->set(refs[0].node,refs[0].bounds(),numPrimitives);
return;
}
/* open all large nodes */
refs.resize(nextRef);
open_sequential(numPrimitives);
/* fast path for small geometries */
if (refs.size() == 1) {
bvh->set(refs[0].node,refs[0].bounds(),numPrimitives);
return;
}
/* compute PrimRefs */
prims.resize(refs.size());
const PrimInfo pinfo = parallel_reduce(size_t(0), refs.size(), size_t(1024), PrimInfo(empty), [&] (const range<size_t>& r) -> PrimInfo
{
PrimInfo pinfo(empty);
for (size_t i=r.begin(); i<r.end(); i++) {
pinfo.add(refs[i].bounds());
prims[i] = PrimRef(refs[i].bounds(),(size_t)refs[i].node);
}
return pinfo;
}, [] (const PrimInfo& a, const PrimInfo& b) { return PrimInfo::merge(a,b); });
/* skip if all objects where empty */
if (pinfo.size() == 0)
bvh->set(BVH4::emptyNode,empty,0);
/* otherwise build toplevel hierarchy */
else
{
BVH4::NodeRef root;
BVHBuilderBinnedSAH::build<BVH4::NodeRef>
(root,
[&] { return bvh->alloc.threadLocal2(); },
[&] (const isa::BVHBuilderBinnedSAH::BuildRecord& current, BVHBuilderBinnedSAH::BuildRecord* children, const size_t N, FastAllocator::ThreadLocal2* alloc) -> int
{
BVH4::Node* node = (BVH4::Node*) alloc->alloc0.malloc(sizeof(BVH4::Node)); node->clear();
for (size_t i=0; i<N; i++) {
node->set(i,children[i].pinfo.geomBounds);
children[i].parent = (size_t*)&node->child(i);
}
*current.parent = bvh->encodeNode(node);
return 0;
},
[&] (const BVHBuilderBinnedSAH::BuildRecord& current, FastAllocator::ThreadLocal2* alloc) -> int
{
assert(current.prims.size() == 1);
*current.parent = (BVH4::NodeRef) prims[current.prims.begin()].ID();
return 1;
},
[&] (size_t dn) { bvh->scene->progressMonitor(0); },
prims.data(),pinfo,BVH4::N,BVH4::maxBuildDepthLeaf,4,1,1,1.0f,1.0f);
bvh->set(root,pinfo.geomBounds,numPrimitives);
}
#if PROFILE
});
#endif
bvh->alloc.cleanup();
bvh->postBuild(t0);
}
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();
}
}