blender/intern/cycles/bvh/bvh.cpp
Sergey Sharybin 828abaf11c Cycles: Split BVH nodes storage into inner and leaf nodes
This way we can get rid of inefficient memory usage caused by BVH boundbox
part being unused by leaf nodes but still being allocated for them. Doing
such split allows to save 6 of float4 values for QBVH per leaf node and 3
of float4 values for regular BVH per leaf node.

This translates into following memory save using 01.01.01.G rendered
without hair:

                   Device memory size   Device memory peak   Global memory peak
Before the patch:  4957                 5051                 7668
With the patch:    4467                 4562                 7332

The measurements are done against current master. Still need to run speed tests
and it's hard to predict if it's faster or not: on the one hand leaf nodes are
now much more coherent in cache, on the other hand they're not so much coherent
with regular nodes anymore.

Reviewers: brecht, juicyfruit

Subscribers: venomgfx, eyecandy

Differential Revision: https://developer.blender.org/D1236
2015-04-20 17:29:51 +05:00

1016 lines
27 KiB
C++

/*
* Adapted from code copyright 2009-2010 NVIDIA Corporation
* Modifications Copyright 2011, Blender Foundation.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "mesh.h"
#include "object.h"
#include "scene.h"
#include "curves.h"
#include "bvh.h"
#include "bvh_build.h"
#include "bvh_node.h"
#include "bvh_params.h"
#include "util_cache.h"
#include "util_debug.h"
#include "util_foreach.h"
#include "util_logging.h"
#include "util_map.h"
#include "util_progress.h"
#include "util_system.h"
#include "util_types.h"
#include "util_math.h"
CCL_NAMESPACE_BEGIN
/* Pack Utility */
struct BVHStackEntry
{
const BVHNode *node;
int idx;
BVHStackEntry(const BVHNode* n = 0, int i = 0)
: node(n), idx(i)
{
}
int encodeIdx() const
{
return (node->is_leaf())? ~idx: idx;
}
};
/* BVH */
BVH::BVH(const BVHParams& params_, const vector<Object*>& objects_)
: params(params_), objects(objects_)
{
}
BVH *BVH::create(const BVHParams& params, const vector<Object*>& objects)
{
if(params.use_qbvh)
return new QBVH(params, objects);
else
return new RegularBVH(params, objects);
}
/* Cache */
bool BVH::cache_read(CacheData& key)
{
key.add(system_cpu_bits());
key.add(&params, sizeof(params));
foreach(Object *ob, objects) {
Mesh *mesh = ob->mesh;
key.add(mesh->verts);
key.add(mesh->triangles);
key.add(mesh->curve_keys);
key.add(mesh->curves);
key.add(&ob->bounds, sizeof(ob->bounds));
key.add(&ob->visibility, sizeof(ob->visibility));
key.add(&mesh->transform_applied, sizeof(bool));
if(mesh->use_motion_blur) {
Attribute *attr = mesh->attributes.find(ATTR_STD_MOTION_VERTEX_POSITION);
if(attr)
key.add(attr->buffer);
attr = mesh->curve_attributes.find(ATTR_STD_MOTION_VERTEX_POSITION);
if(attr)
key.add(attr->buffer);
}
}
CacheData value;
if(Cache::global.lookup(key, value)) {
cache_filename = key.get_filename();
if(!(value.read(pack.root_index) &&
value.read(pack.SAH) &&
value.read(pack.nodes) &&
value.read(pack.object_node) &&
value.read(pack.tri_woop) &&
value.read(pack.prim_type) &&
value.read(pack.prim_visibility) &&
value.read(pack.prim_index) &&
value.read(pack.prim_object)))
{
/* Clear the pack if load failed. */
pack.root_index = 0;
pack.SAH = 0.0f;
pack.nodes.clear();
pack.object_node.clear();
pack.tri_woop.clear();
pack.prim_type.clear();
pack.prim_visibility.clear();
pack.prim_index.clear();
pack.prim_object.clear();
return false;
}
return true;
}
return false;
}
void BVH::cache_write(CacheData& key)
{
CacheData value;
value.add(pack.root_index);
value.add(pack.SAH);
value.add(pack.nodes);
value.add(pack.object_node);
value.add(pack.tri_woop);
value.add(pack.prim_type);
value.add(pack.prim_visibility);
value.add(pack.prim_index);
value.add(pack.prim_object);
Cache::global.insert(key, value);
cache_filename = key.get_filename();
}
void BVH::clear_cache_except()
{
set<string> except;
if(!cache_filename.empty())
except.insert(cache_filename);
foreach(Object *ob, objects) {
Mesh *mesh = ob->mesh;
BVH *bvh = mesh->bvh;
if(bvh && !bvh->cache_filename.empty())
except.insert(bvh->cache_filename);
}
Cache::global.clear_except("bvh", except);
}
/* Building */
void BVH::build(Progress& progress)
{
progress.set_substatus("Building BVH");
/* cache read */
CacheData key("bvh");
if(params.use_cache) {
progress.set_substatus("Looking in BVH cache");
if(cache_read(key))
return;
}
/* build nodes */
vector<int> prim_type;
vector<int> prim_index;
vector<int> prim_object;
BVHBuild bvh_build(objects, prim_type, prim_index, prim_object, params, progress);
BVHNode *root = bvh_build.run();
if(progress.get_cancel()) {
if(root) root->deleteSubtree();
return;
}
/* todo: get rid of this copy */
pack.prim_type = prim_type;
pack.prim_index = prim_index;
pack.prim_object = prim_object;
prim_type.free_memory();
prim_index.free_memory();
prim_object.free_memory();
/* compute SAH */
if(!params.top_level)
pack.SAH = root->computeSubtreeSAHCost(params);
if(progress.get_cancel()) {
root->deleteSubtree();
return;
}
/* pack triangles */
progress.set_substatus("Packing BVH triangles and strands");
pack_primitives();
if(progress.get_cancel()) {
root->deleteSubtree();
return;
}
/* pack nodes */
progress.set_substatus("Packing BVH nodes");
pack_nodes(root);
/* free build nodes */
root->deleteSubtree();
if(progress.get_cancel()) return;
/* cache write */
if(params.use_cache) {
progress.set_substatus("Writing BVH cache");
cache_write(key);
/* clear other bvh files from cache */
if(params.top_level)
clear_cache_except();
}
}
/* Refitting */
void BVH::refit(Progress& progress)
{
progress.set_substatus("Packing BVH primitives");
pack_primitives();
if(progress.get_cancel()) return;
progress.set_substatus("Refitting BVH nodes");
refit_nodes();
}
/* Triangles */
void BVH::pack_triangle(int idx, float4 woop[3])
{
int tob = pack.prim_object[idx];
assert(tob >= 0 && tob < objects.size());
const Mesh *mesh = objects[tob]->mesh;
int tidx = pack.prim_index[idx];
const int *vidx = mesh->triangles[tidx].v;
const float3* vpos = &mesh->verts[0];
float3 v0 = vpos[vidx[0]];
float3 v1 = vpos[vidx[1]];
float3 v2 = vpos[vidx[2]];
woop[0] = float3_to_float4(v0);
woop[1] = float3_to_float4(v1);
woop[2] = float3_to_float4(v2);
}
/* Curves*/
void BVH::pack_primitives()
{
int nsize = TRI_NODE_SIZE;
size_t tidx_size = pack.prim_index.size();
pack.tri_woop.clear();
pack.tri_woop.resize(tidx_size * nsize);
pack.prim_visibility.clear();
pack.prim_visibility.resize(tidx_size);
for(unsigned int i = 0; i < tidx_size; i++) {
if(pack.prim_index[i] != -1) {
float4 woop[3];
if(pack.prim_type[i] & PRIMITIVE_TRIANGLE) {
pack_triangle(i, woop);
}
else {
/* Avoid use of uninitialized memory. */
memset(&woop, 0, sizeof(woop));
}
memcpy(&pack.tri_woop[i * nsize], woop, sizeof(float4)*3);
int tob = pack.prim_object[i];
Object *ob = objects[tob];
pack.prim_visibility[i] = ob->visibility;
if(pack.prim_type[i] & PRIMITIVE_ALL_CURVE)
pack.prim_visibility[i] |= PATH_RAY_CURVE;
}
else {
memset(&pack.tri_woop[i * nsize], 0, sizeof(float4)*3);
pack.prim_visibility[i] = 0;
}
}
}
/* Pack Instances */
void BVH::pack_instances(size_t nodes_size, size_t leaf_nodes_size)
{
/* The BVH's for instances are built separately, but for traversal all
* BVH's are stored in global arrays. This function merges them into the
* top level BVH, adjusting indexes and offsets where appropriate. */
bool use_qbvh = params.use_qbvh;
size_t nsize = (use_qbvh)? BVH_QNODE_SIZE: BVH_NODE_SIZE;
size_t nsize_leaf = (use_qbvh)? BVH_QNODE_LEAF_SIZE: BVH_NODE_LEAF_SIZE;
/* adjust primitive index to point to the triangle in the global array, for
* meshes with transform applied and already in the top level BVH */
for(size_t i = 0; i < pack.prim_index.size(); i++)
if(pack.prim_index[i] != -1) {
if(pack.prim_type[i] & PRIMITIVE_ALL_CURVE)
pack.prim_index[i] += objects[pack.prim_object[i]]->mesh->curve_offset;
else
pack.prim_index[i] += objects[pack.prim_object[i]]->mesh->tri_offset;
}
/* track offsets of instanced BVH data in global array */
size_t prim_offset = pack.prim_index.size();
size_t nodes_offset = nodes_size;
size_t nodes_leaf_offset = leaf_nodes_size;
/* clear array that gives the node indexes for instanced objects */
pack.object_node.clear();
/* reserve */
size_t prim_index_size = pack.prim_index.size();
size_t tri_woop_size = pack.tri_woop.size();
size_t pack_prim_index_offset = prim_index_size;
size_t pack_tri_woop_offset = tri_woop_size;
size_t pack_nodes_offset = nodes_size;
size_t pack_leaf_nodes_offset = leaf_nodes_size;
size_t object_offset = 0;
map<Mesh*, int> mesh_map;
foreach(Object *ob, objects) {
Mesh *mesh = ob->mesh;
BVH *bvh = mesh->bvh;
if(!mesh->transform_applied) {
if(mesh_map.find(mesh) == mesh_map.end()) {
prim_index_size += bvh->pack.prim_index.size();
tri_woop_size += bvh->pack.tri_woop.size();
nodes_size += bvh->pack.nodes.size();
leaf_nodes_size += bvh->pack.leaf_nodes.size();
mesh_map[mesh] = 1;
}
}
}
mesh_map.clear();
pack.prim_index.resize(prim_index_size);
pack.prim_type.resize(prim_index_size);
pack.prim_object.resize(prim_index_size);
pack.prim_visibility.resize(prim_index_size);
pack.tri_woop.resize(tri_woop_size);
pack.nodes.resize(nodes_size);
pack.leaf_nodes.resize(leaf_nodes_size);
pack.object_node.resize(objects.size());
int *pack_prim_index = (pack.prim_index.size())? &pack.prim_index[0]: NULL;
int *pack_prim_type = (pack.prim_type.size())? &pack.prim_type[0]: NULL;
int *pack_prim_object = (pack.prim_object.size())? &pack.prim_object[0]: NULL;
uint *pack_prim_visibility = (pack.prim_visibility.size())? &pack.prim_visibility[0]: NULL;
float4 *pack_tri_woop = (pack.tri_woop.size())? &pack.tri_woop[0]: NULL;
int4 *pack_nodes = (pack.nodes.size())? &pack.nodes[0]: NULL;
int4 *pack_leaf_nodes = (pack.leaf_nodes.size())? &pack.leaf_nodes[0]: NULL;
/* merge */
foreach(Object *ob, objects) {
Mesh *mesh = ob->mesh;
/* if mesh transform is applied, that means it's already in the top
* level BVH, and we don't need to merge it in */
if(mesh->transform_applied) {
pack.object_node[object_offset++] = 0;
continue;
}
/* if mesh already added once, don't add it again, but used set
* node offset for this object */
map<Mesh*, int>::iterator it = mesh_map.find(mesh);
if(mesh_map.find(mesh) != mesh_map.end()) {
int noffset = it->second;
pack.object_node[object_offset++] = noffset;
continue;
}
BVH *bvh = mesh->bvh;
int noffset = nodes_offset/nsize;
int noffset_leaf = nodes_leaf_offset/nsize_leaf;
int mesh_tri_offset = mesh->tri_offset;
int mesh_curve_offset = mesh->curve_offset;
/* fill in node indexes for instances */
if(bvh->pack.root_index == -1)
pack.object_node[object_offset++] = -noffset_leaf-1;
else
pack.object_node[object_offset++] = noffset;
mesh_map[mesh] = pack.object_node[object_offset-1];
/* merge primitive and object indexes */
if(bvh->pack.prim_index.size()) {
size_t bvh_prim_index_size = bvh->pack.prim_index.size();
int *bvh_prim_index = &bvh->pack.prim_index[0];
int *bvh_prim_type = &bvh->pack.prim_type[0];
uint *bvh_prim_visibility = &bvh->pack.prim_visibility[0];
for(size_t i = 0; i < bvh_prim_index_size; i++) {
if(bvh->pack.prim_type[i] & PRIMITIVE_ALL_CURVE)
pack_prim_index[pack_prim_index_offset] = bvh_prim_index[i] + mesh_curve_offset;
else
pack_prim_index[pack_prim_index_offset] = bvh_prim_index[i] + mesh_tri_offset;
pack_prim_type[pack_prim_index_offset] = bvh_prim_type[i];
pack_prim_visibility[pack_prim_index_offset] = bvh_prim_visibility[i];
pack_prim_object[pack_prim_index_offset] = 0; // unused for instances
pack_prim_index_offset++;
}
}
/* merge triangle intersection data */
if(bvh->pack.tri_woop.size()) {
memcpy(pack_tri_woop + pack_tri_woop_offset, &bvh->pack.tri_woop[0],
bvh->pack.tri_woop.size()*sizeof(float4));
pack_tri_woop_offset += bvh->pack.tri_woop.size();
}
/* merge nodes */
if(bvh->pack.leaf_nodes.size()) {
int4 *leaf_nodes_offset = &bvh->pack.leaf_nodes[0];
size_t leaf_nodes_offset_size = bvh->pack.leaf_nodes.size();
for(size_t i = 0, j = 0; i < leaf_nodes_offset_size; i+=nsize_leaf, j++) {
int4 data = leaf_nodes_offset[i];
data.x += prim_offset;
data.y += prim_offset;
pack_leaf_nodes[pack_leaf_nodes_offset] = data;
pack_leaf_nodes_offset += nsize_leaf;
}
}
if(bvh->pack.nodes.size()) {
/* For QBVH we're packing a child bbox into 6 float4,
* and for regular BVH they're packed into 3 float4.
*/
size_t nsize_bbox = (use_qbvh)? 6: 3;
int4 *bvh_nodes = &bvh->pack.nodes[0];
size_t bvh_nodes_size = bvh->pack.nodes.size();
for(size_t i = 0, j = 0; i < bvh_nodes_size; i+=nsize, j++) {
memcpy(pack_nodes + pack_nodes_offset, bvh_nodes + i, nsize_bbox*sizeof(int4));
/* modify offsets into arrays */
int4 data = bvh_nodes[i + nsize_bbox];
data.x += (data.x < 0)? -noffset_leaf: noffset;
data.y += (data.y < 0)? -noffset_leaf: noffset;
if(use_qbvh) {
data.z += (data.z < 0)? -noffset_leaf: noffset;
data.w += (data.w < 0)? -noffset_leaf: noffset;
}
pack_nodes[pack_nodes_offset + nsize_bbox] = data;
/* Usually this copies nothing, but we better
* be prepared for possible node size extension.
*/
memcpy(&pack_nodes[pack_nodes_offset + nsize_bbox+1],
&bvh_nodes[i + nsize_bbox+1],
sizeof(int4) * (nsize - (nsize_bbox+1)));
pack_nodes_offset += nsize;
}
}
nodes_offset += bvh->pack.nodes.size();
nodes_leaf_offset += bvh->pack.leaf_nodes.size();
prim_offset += bvh->pack.prim_index.size();
}
}
/* Regular BVH */
RegularBVH::RegularBVH(const BVHParams& params_, const vector<Object*>& objects_)
: BVH(params_, objects_)
{
}
void RegularBVH::pack_leaf(const BVHStackEntry& e, const LeafNode *leaf)
{
float4 data[BVH_NODE_LEAF_SIZE];
memset(data, 0, sizeof(data));
if(leaf->num_triangles() == 1 && pack.prim_index[leaf->m_lo] == -1) {
/* object */
data[0].x = __int_as_float(~(leaf->m_lo));
data[0].y = __int_as_float(0);
}
else {
/* triangle */
data[0].x = __int_as_float(leaf->m_lo);
data[0].y = __int_as_float(leaf->m_hi);
}
data[0].z = __uint_as_float(leaf->m_visibility);
if(leaf->num_triangles() != 0) {
data[0].w = __uint_as_float(pack.prim_type[leaf->m_lo]);
}
memcpy(&pack.leaf_nodes[e.idx * BVH_NODE_LEAF_SIZE], data, sizeof(float4)*BVH_NODE_LEAF_SIZE);
}
void RegularBVH::pack_inner(const BVHStackEntry& e, const BVHStackEntry& e0, const BVHStackEntry& e1)
{
pack_node(e.idx, e0.node->m_bounds, e1.node->m_bounds, e0.encodeIdx(), e1.encodeIdx(), e0.node->m_visibility, e1.node->m_visibility);
}
void RegularBVH::pack_node(int idx, const BoundBox& b0, const BoundBox& b1, int c0, int c1, uint visibility0, uint visibility1)
{
int4 data[BVH_NODE_SIZE] =
{
make_int4(__float_as_int(b0.min.x), __float_as_int(b1.min.x), __float_as_int(b0.max.x), __float_as_int(b1.max.x)),
make_int4(__float_as_int(b0.min.y), __float_as_int(b1.min.y), __float_as_int(b0.max.y), __float_as_int(b1.max.y)),
make_int4(__float_as_int(b0.min.z), __float_as_int(b1.min.z), __float_as_int(b0.max.z), __float_as_int(b1.max.z)),
make_int4(c0, c1, visibility0, visibility1)
};
memcpy(&pack.nodes[idx * BVH_NODE_SIZE], data, sizeof(int4)*BVH_NODE_SIZE);
}
void RegularBVH::pack_nodes(const BVHNode *root)
{
size_t tot_node_size = root->getSubtreeSize(BVH_STAT_NODE_COUNT);
size_t leaf_node_size = root->getSubtreeSize(BVH_STAT_LEAF_COUNT);
size_t node_size = tot_node_size - leaf_node_size;
/* resize arrays */
pack.nodes.clear();
/* for top level BVH, first merge existing BVH's so we know the offsets */
if(params.top_level) {
pack_instances(node_size*BVH_NODE_SIZE,
leaf_node_size*BVH_NODE_LEAF_SIZE);
}
else {
pack.nodes.resize(node_size*BVH_NODE_SIZE);
pack.leaf_nodes.resize(leaf_node_size*BVH_NODE_LEAF_SIZE);
}
int nextNodeIdx = 0, nextLeafNodeIdx = 0;
vector<BVHStackEntry> stack;
stack.reserve(BVHParams::MAX_DEPTH*2);
if(root->is_leaf())
stack.push_back(BVHStackEntry(root, nextLeafNodeIdx++));
else
stack.push_back(BVHStackEntry(root, nextNodeIdx++));
while(stack.size()) {
BVHStackEntry e = stack.back();
stack.pop_back();
if(e.node->is_leaf()) {
/* leaf node */
const LeafNode* leaf = reinterpret_cast<const LeafNode*>(e.node);
pack_leaf(e, leaf);
}
else {
/* innner node */
int idx0 = (e.node->get_child(0)->is_leaf())? (nextLeafNodeIdx++) : (nextNodeIdx++);
int idx1 = (e.node->get_child(1)->is_leaf())? (nextLeafNodeIdx++) : (nextNodeIdx++);
stack.push_back(BVHStackEntry(e.node->get_child(0), idx0));
stack.push_back(BVHStackEntry(e.node->get_child(1), idx1));
pack_inner(e, stack[stack.size()-2], stack[stack.size()-1]);
}
}
/* root index to start traversal at, to handle case of single leaf node */
pack.root_index = (root->is_leaf())? -1: 0;
}
void RegularBVH::refit_nodes()
{
assert(!params.top_level);
BoundBox bbox = BoundBox::empty;
uint visibility = 0;
refit_node(0, (pack.root_index == -1)? true: false, bbox, visibility);
}
void RegularBVH::refit_node(int idx, bool leaf, BoundBox& bbox, uint& visibility)
{
if(leaf) {
int4 *data = &pack.leaf_nodes[idx*BVH_NODE_LEAF_SIZE];
int c0 = data[0].x;
int c1 = data[0].y;
/* refit leaf node */
for(int prim = c0; prim < c1; prim++) {
int pidx = pack.prim_index[prim];
int tob = pack.prim_object[prim];
Object *ob = objects[tob];
if(pidx == -1) {
/* object instance */
bbox.grow(ob->bounds);
}
else {
/* primitives */
const Mesh *mesh = ob->mesh;
if(pack.prim_type[prim] & PRIMITIVE_ALL_CURVE) {
/* curves */
int str_offset = (params.top_level)? mesh->curve_offset: 0;
const Mesh::Curve& curve = mesh->curves[pidx - str_offset];
int k = PRIMITIVE_UNPACK_SEGMENT(pack.prim_type[prim]);
curve.bounds_grow(k, &mesh->curve_keys[0], bbox);
visibility |= PATH_RAY_CURVE;
/* motion curves */
if(mesh->use_motion_blur) {
Attribute *attr = mesh->curve_attributes.find(ATTR_STD_MOTION_VERTEX_POSITION);
if(attr) {
size_t mesh_size = mesh->curve_keys.size();
size_t steps = mesh->motion_steps - 1;
float4 *key_steps = attr->data_float4();
for(size_t i = 0; i < steps; i++)
curve.bounds_grow(k, key_steps + i*mesh_size, bbox);
}
}
}
else {
/* triangles */
int tri_offset = (params.top_level)? mesh->tri_offset: 0;
const Mesh::Triangle& triangle = mesh->triangles[pidx - tri_offset];
const float3 *vpos = &mesh->verts[0];
triangle.bounds_grow(vpos, bbox);
/* motion triangles */
if(mesh->use_motion_blur) {
Attribute *attr = mesh->attributes.find(ATTR_STD_MOTION_VERTEX_POSITION);
if(attr) {
size_t mesh_size = mesh->verts.size();
size_t steps = mesh->motion_steps - 1;
float3 *vert_steps = attr->data_float3();
for(size_t i = 0; i < steps; i++)
triangle.bounds_grow(vert_steps + i*mesh_size, bbox);
}
}
}
}
visibility |= ob->visibility;
}
/* TODO(sergey): De-duplicate with pack_leaf(). */
float4 leaf_data[BVH_NODE_LEAF_SIZE];
leaf_data[0].x = __int_as_float(c0);
leaf_data[0].y = __int_as_float(c1);
leaf_data[0].z = __uint_as_float(visibility);
leaf_data[0].w = __uint_as_float(data[0].w);
memcpy(&pack.leaf_nodes[idx * BVH_NODE_LEAF_SIZE],
leaf_data,
sizeof(float4)*BVH_NODE_LEAF_SIZE);
}
else {
int4 *data = &pack.nodes[idx*BVH_NODE_SIZE];
int c0 = data[3].x;
int c1 = data[3].y;
/* refit inner node, set bbox from children */
BoundBox bbox0 = BoundBox::empty, bbox1 = BoundBox::empty;
uint visibility0 = 0, visibility1 = 0;
refit_node((c0 < 0)? -c0-1: c0, (c0 < 0), bbox0, visibility0);
refit_node((c1 < 0)? -c1-1: c1, (c1 < 0), bbox1, visibility1);
pack_node(idx, bbox0, bbox1, c0, c1, visibility0, visibility1);
bbox.grow(bbox0);
bbox.grow(bbox1);
visibility = visibility0|visibility1;
}
}
/* QBVH */
QBVH::QBVH(const BVHParams& params_, const vector<Object*>& objects_)
: BVH(params_, objects_)
{
params.use_qbvh = true;
}
void QBVH::pack_leaf(const BVHStackEntry& e, const LeafNode *leaf)
{
float4 data[BVH_QNODE_LEAF_SIZE];
memset(data, 0, sizeof(data));
if(leaf->num_triangles() == 1 && pack.prim_index[leaf->m_lo] == -1) {
/* object */
data[0].x = __int_as_float(~(leaf->m_lo));
data[0].y = __int_as_float(0);
}
else {
/* triangle */
data[0].x = __int_as_float(leaf->m_lo);
data[0].y = __int_as_float(leaf->m_hi);
}
data[0].z = __uint_as_float(leaf->m_visibility);
if(leaf->num_triangles() != 0) {
data[0].w = __uint_as_float(pack.prim_type[leaf->m_lo]);
}
memcpy(&pack.leaf_nodes[e.idx * BVH_QNODE_LEAF_SIZE], data, sizeof(float4)*BVH_QNODE_LEAF_SIZE);
}
void QBVH::pack_inner(const BVHStackEntry& e, const BVHStackEntry *en, int num)
{
float4 data[BVH_QNODE_SIZE];
for(int i = 0; i < num; i++) {
float3 bb_min = en[i].node->m_bounds.min;
float3 bb_max = en[i].node->m_bounds.max;
data[0][i] = bb_min.x;
data[1][i] = bb_max.x;
data[2][i] = bb_min.y;
data[3][i] = bb_max.y;
data[4][i] = bb_min.z;
data[5][i] = bb_max.z;
data[6][i] = __int_as_float(en[i].encodeIdx());
}
for(int i = num; i < 4; i++) {
/* We store BB which would never be recorded as intersection
* so kernel might safely assume there are always 4 child nodes.
*/
data[0][i] = FLT_MAX;
data[1][i] = -FLT_MAX;
data[2][i] = FLT_MAX;
data[3][i] = -FLT_MAX;
data[4][i] = FLT_MAX;
data[5][i] = -FLT_MAX;
data[6][i] = __int_as_float(0);
}
memcpy(&pack.nodes[e.idx * BVH_QNODE_SIZE], data, sizeof(float4)*BVH_QNODE_SIZE);
}
/* Quad SIMD Nodes */
void QBVH::pack_nodes(const BVHNode *root)
{
size_t tot_node_size = root->getSubtreeSize(BVH_STAT_QNODE_COUNT);
size_t leaf_node_size = root->getSubtreeSize(BVH_STAT_LEAF_COUNT);
size_t node_size = tot_node_size - leaf_node_size;
/* resize arrays */
pack.nodes.clear();
pack.leaf_nodes.clear();
/* for top level BVH, first merge existing BVH's so we know the offsets */
if(params.top_level) {
pack_instances(node_size*BVH_QNODE_SIZE,
leaf_node_size*BVH_QNODE_LEAF_SIZE);
}
else {
pack.nodes.resize(node_size*BVH_QNODE_SIZE);
pack.leaf_nodes.resize(leaf_node_size*BVH_QNODE_LEAF_SIZE);
}
int nextNodeIdx = 0, nextLeafNodeIdx = 0;
vector<BVHStackEntry> stack;
stack.reserve(BVHParams::MAX_DEPTH*2);
if(root->is_leaf()) {
stack.push_back(BVHStackEntry(root, nextLeafNodeIdx++));
}
else {
stack.push_back(BVHStackEntry(root, nextNodeIdx++));
}
while(stack.size()) {
BVHStackEntry e = stack.back();
stack.pop_back();
if(e.node->is_leaf()) {
/* leaf node */
const LeafNode* leaf = reinterpret_cast<const LeafNode*>(e.node);
pack_leaf(e, leaf);
}
else {
/* inner node */
const BVHNode *node = e.node;
const BVHNode *node0 = node->get_child(0);
const BVHNode *node1 = node->get_child(1);
/* collect nodes */
const BVHNode *nodes[4];
int numnodes = 0;
if(node0->is_leaf()) {
nodes[numnodes++] = node0;
}
else {
nodes[numnodes++] = node0->get_child(0);
nodes[numnodes++] = node0->get_child(1);
}
if(node1->is_leaf()) {
nodes[numnodes++] = node1;
}
else {
nodes[numnodes++] = node1->get_child(0);
nodes[numnodes++] = node1->get_child(1);
}
/* push entries on the stack */
for(int i = 0; i < numnodes; i++) {
int idx;
if(nodes[i]->is_leaf()) {
idx = nextLeafNodeIdx++;
}
else {
idx = nextNodeIdx++;
}
stack.push_back(BVHStackEntry(nodes[i], idx));
}
/* set node */
pack_inner(e, &stack[stack.size()-numnodes], numnodes);
}
}
/* root index to start traversal at, to handle case of single leaf node */
pack.root_index = (root->is_leaf())? -1: 0;
}
void QBVH::refit_nodes()
{
assert(!params.top_level);
BoundBox bbox = BoundBox::empty;
uint visibility = 0;
refit_node(0, (pack.root_index == -1)? true: false, bbox, visibility);
}
void QBVH::refit_node(int idx, bool leaf, BoundBox& bbox, uint& visibility)
{
if(leaf) {
int4 *data = &pack.leaf_nodes[idx*BVH_QNODE_LEAF_SIZE];
int4 c = data[0];
/* Refit leaf node. */
for(int prim = c.x; prim < c.y; prim++) {
int pidx = pack.prim_index[prim];
int tob = pack.prim_object[prim];
Object *ob = objects[tob];
if(pidx == -1) {
/* Object instance. */
bbox.grow(ob->bounds);
}
else {
/* Primitives. */
const Mesh *mesh = ob->mesh;
if(pack.prim_type[prim] & PRIMITIVE_ALL_CURVE) {
/* Curves. */
int str_offset = (params.top_level)? mesh->curve_offset: 0;
const Mesh::Curve& curve = mesh->curves[pidx - str_offset];
int k = PRIMITIVE_UNPACK_SEGMENT(pack.prim_type[prim]);
curve.bounds_grow(k, &mesh->curve_keys[0], bbox);
visibility |= PATH_RAY_CURVE;
/* Motion curves. */
if(mesh->use_motion_blur) {
Attribute *attr = mesh->curve_attributes.find(ATTR_STD_MOTION_VERTEX_POSITION);
if(attr) {
size_t mesh_size = mesh->curve_keys.size();
size_t steps = mesh->motion_steps - 1;
float4 *key_steps = attr->data_float4();
for(size_t i = 0; i < steps; i++)
curve.bounds_grow(k, key_steps + i*mesh_size, bbox);
}
}
}
else {
/* Triangles. */
int tri_offset = (params.top_level)? mesh->tri_offset: 0;
const Mesh::Triangle& triangle = mesh->triangles[pidx - tri_offset];
const float3 *vpos = &mesh->verts[0];
triangle.bounds_grow(vpos, bbox);
/* Motion triangles. */
if(mesh->use_motion_blur) {
Attribute *attr = mesh->attributes.find(ATTR_STD_MOTION_VERTEX_POSITION);
if(attr) {
size_t mesh_size = mesh->verts.size();
size_t steps = mesh->motion_steps - 1;
float3 *vert_steps = attr->data_float3();
for(size_t i = 0; i < steps; i++)
triangle.bounds_grow(vert_steps + i*mesh_size, bbox);
}
}
}
}
visibility |= ob->visibility;
}
/* TODO(sergey): This is actually a copy of pack_leaf(),
* but this chunk of code only knows actual data and has
* no idea about BVHNode.
*
* Would be nice to de-duplicate code, but trying to make
* making code more general ends up in much nastier code
* in my opinion so far.
*
* Same applies to the inner nodes case below.
*/
float4 leaf_data[BVH_QNODE_LEAF_SIZE];
leaf_data[0].x = __int_as_float(c.x);
leaf_data[0].y = __int_as_float(c.y);
leaf_data[0].z = __uint_as_float(visibility);
leaf_data[0].w = __uint_as_float(c.w);
memcpy(&pack.leaf_nodes[idx * BVH_QNODE_LEAF_SIZE],
leaf_data,
sizeof(float4)*BVH_QNODE_LEAF_SIZE);
}
else {
int4 *data = &pack.nodes[idx*BVH_QNODE_SIZE];
int4 c = data[6];
/* Refit inner node, set bbox from children. */
BoundBox child_bbox[4] = {BoundBox::empty,
BoundBox::empty,
BoundBox::empty,
BoundBox::empty};
uint child_visibility[4] = {0};
int num_nodes = 0;
for(int i = 0; i < 4; ++i) {
if(c[i] != 0) {
refit_node((c[i] < 0)? -c[i]-1: c[i], (c[i] < 0),
child_bbox[i], child_visibility[i]);
++num_nodes;
bbox.grow(child_bbox[i]);
visibility |= child_visibility[i];
}
}
float4 inner_data[BVH_QNODE_SIZE];
for(int i = 0; i < 4; ++i) {
float3 bb_min = child_bbox[i].min;
float3 bb_max = child_bbox[i].max;
inner_data[0][i] = bb_min.x;
inner_data[1][i] = bb_max.x;
inner_data[2][i] = bb_min.y;
inner_data[3][i] = bb_max.y;
inner_data[4][i] = bb_min.z;
inner_data[5][i] = bb_max.z;
inner_data[6][i] = __int_as_float(c[i]);
}
memcpy(&pack.nodes[idx * BVH_QNODE_SIZE],
inner_data,
sizeof(float4)*BVH_QNODE_SIZE);
}
}
CCL_NAMESPACE_END