blender/intern/cycles/bvh/bvh.cpp
2012-06-09 17:22:52 +00:00

733 lines
18 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 "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_map.h"
#include "util_progress.h"
#include "util_types.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(&params, sizeof(params));
foreach(Object *ob, objects) {
key.add(ob->mesh->verts);
key.add(ob->mesh->triangles);
key.add(&ob->bounds, sizeof(ob->bounds));
key.add(&ob->visibility, sizeof(ob->visibility));
key.add(&ob->mesh->transform_applied, sizeof(bool));
}
CacheData value;
if(Cache::global.lookup(key, value)) {
cache_filename = key.get_filename();
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_visibility);
value.read(pack.prim_index);
value.read(pack.prim_object);
value.read(pack.is_leaf);
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_visibility);
value.add(pack.prim_index);
value.add(pack.prim_object);
value.add(pack.is_leaf);
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_index;
vector<int> prim_object;
BVHBuild bvh_build(objects, 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_index = prim_index;
pack.prim_object = prim_object;
/* 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");
pack_triangles();
if(progress.get_cancel()) {
root->deleteSubtree();
return;
}
/* pack nodes */
progress.set_substatus("Packing BVH nodes");
array<int> tmp_prim_object = pack.prim_object;
pack_nodes(tmp_prim_object, 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 triangles");
pack_triangles();
if(progress.get_cancel()) return;
progress.set_substatus("Refitting BVH nodes");
refit_nodes();
}
/* Triangles */
void BVH::pack_triangle(int idx, float4 woop[3])
{
/* create Woop triangle */
int tob = pack.prim_object[idx];
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]];
float3 r0 = v0 - v2;
float3 r1 = v1 - v2;
float3 r2 = cross(r0, r1);
if(dot(r0, r0) == 0.0f || dot(r1, r1) == 0.0f || dot(r2, r2) == 0.0f) {
/* degenerate */
woop[0] = make_float4(0.0f, 0.0f, 0.0f, 0.0f);
woop[1] = make_float4(0.0f, 0.0f, 0.0f, 0.0f);
woop[2] = make_float4(0.0f, 0.0f, 0.0f, 0.0f);
}
else {
Transform t = make_transform(
r0.x, r1.x, r2.x, v2.x,
r0.y, r1.y, r2.y, v2.y,
r0.z, r1.z, r2.z, v2.z,
0.0f, 0.0f, 0.0f, 1.0f);
t = transform_inverse(t);
woop[0] = make_float4(t.z.x, t.z.y, t.z.z, -t.z.w);
woop[1] = make_float4(t.x.x, t.x.y, t.x.z, t.x.w);
woop[2] = make_float4(t.y.x, t.y.y, t.y.z, t.y.w);
}
}
void BVH::pack_triangles()
{
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];
pack_triangle(i, 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;
}
}
}
/* Pack Instances */
void BVH::pack_instances(size_t 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;
/* 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)
pack.prim_index[i] += objects[pack.prim_object[i]]->mesh->tri_offset;
/* track offsets of instanced BVH data in global array */
size_t tri_offset = pack.prim_index.size();
size_t nodes_offset = 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 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()*nsize;
mesh_map[mesh] = 1;
}
}
}
mesh_map.clear();
pack.prim_index.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.object_node.resize(objects.size());
int *pack_prim_index = (pack.prim_index.size())? &pack.prim_index[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;
/* 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 mesh_tri_offset = mesh->tri_offset;
/* fill in node indexes for instances */
if(bvh->pack.is_leaf[0])
pack.object_node[object_offset++] = -noffset-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];
uint *bvh_prim_visibility = &bvh->pack.prim_visibility[0];
for(size_t i = 0; i < bvh_prim_index_size; i++) {
pack_prim_index[pack_prim_index_offset] = bvh_prim_index[i] + mesh_tri_offset;
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.nodes.size()) {
size_t nsize_bbox = (use_qbvh)? nsize-2: nsize-1;
int4 *bvh_nodes = &bvh->pack.nodes[0];
size_t bvh_nodes_size = bvh->pack.nodes.size();
int *bvh_is_leaf = &bvh->pack.is_leaf[0];
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];
if(bvh_is_leaf[j]) {
data.x += tri_offset;
data.y += tri_offset;
}
else {
data.x += (data.x < 0)? -noffset: noffset;
data.y += (data.y < 0)? -noffset: noffset;
if(use_qbvh) {
data.z += (data.z < 0)? -noffset: noffset;
data.w += (data.w < 0)? -noffset: noffset;
}
}
pack_nodes[pack_nodes_offset + nsize_bbox] = data;
if(use_qbvh)
pack_nodes[pack_nodes_offset + nsize_bbox+1] = bvh_nodes[i + nsize_bbox+1];
pack_nodes_offset += nsize;
}
}
nodes_offset += bvh->pack.nodes.size();
tri_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)
{
if(leaf->num_triangles() == 1 && pack.prim_index[leaf->m_lo] == -1)
/* object */
pack_node(e.idx, leaf->m_bounds, leaf->m_bounds, ~(leaf->m_lo), 0, leaf->m_visibility, leaf->m_visibility);
else
/* triangle */
pack_node(e.idx, leaf->m_bounds, leaf->m_bounds, leaf->m_lo, leaf->m_hi, leaf->m_visibility, leaf->m_visibility);
}
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(b0.max.x), __float_as_int(b0.min.y), __float_as_int(b0.max.y)),
make_int4(__float_as_int(b1.min.x), __float_as_int(b1.max.x), __float_as_int(b1.min.y), __float_as_int(b1.max.y)),
make_int4(__float_as_int(b0.min.z), __float_as_int(b0.max.z), __float_as_int(b1.min.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 array<int>& prims, const BVHNode *root)
{
size_t node_size = root->getSubtreeSize(BVH_STAT_NODE_COUNT);
/* resize arrays */
pack.nodes.clear();
pack.is_leaf.clear();
pack.is_leaf.resize(node_size);
/* 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);
else
pack.nodes.resize(node_size*BVH_NODE_SIZE);
int nextNodeIdx = 0;
vector<BVHStackEntry> stack;
stack.push_back(BVHStackEntry(root, nextNodeIdx++));
while(stack.size()) {
BVHStackEntry e = stack.back();
stack.pop_back();
pack.is_leaf[e.idx] = e.node->is_leaf();
if(e.node->is_leaf()) {
/* leaf node */
const LeafNode* leaf = reinterpret_cast<const LeafNode*>(e.node);
pack_leaf(e, leaf);
}
else {
/* innner node */
stack.push_back(BVHStackEntry(e.node->get_child(0), nextNodeIdx++));
stack.push_back(BVHStackEntry(e.node->get_child(1), nextNodeIdx++));
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 = (pack.is_leaf[0])? -1: 0;
}
void RegularBVH::refit_nodes()
{
assert(!params.top_level);
BoundBox bbox = BoundBox::empty;
uint visibility = 0;
refit_node(0, (pack.is_leaf[0])? true: false, bbox, visibility);
}
void RegularBVH::refit_node(int idx, bool leaf, BoundBox& bbox, uint& visibility)
{
int4 *data = &pack.nodes[idx*4];
int c0 = data[3].x;
int c1 = data[3].y;
if(leaf) {
/* refit leaf node */
for(int tri = c0; tri < c1; tri++) {
int tidx = pack.prim_index[tri];
int tob = pack.prim_object[tri];
Object *ob = objects[tob];
if(tidx == -1) {
/* object instance */
bbox.grow(ob->bounds);
}
else {
/* triangles */
const Mesh *mesh = ob->mesh;
int tri_offset = (params.top_level)? mesh->tri_offset: 0;
const int *vidx = mesh->triangles[tidx - tri_offset].v;
const float3 *vpos = &mesh->verts[0];
bbox.grow(vpos[vidx[0]]);
bbox.grow(vpos[vidx[1]]);
bbox.grow(vpos[vidx[2]]);
}
visibility |= ob->visibility;
}
pack_node(idx, bbox, bbox, c0, c1, visibility, visibility);
}
else {
/* 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;
/* todo: use visibility */
}
void QBVH::pack_leaf(const BVHStackEntry& e, const LeafNode *leaf)
{
float4 data[BVH_QNODE_SIZE];
memset(data, 0, sizeof(data));
if(leaf->num_triangles() == 1 && pack.prim_index[leaf->m_lo] == -1) {
/* object */
data[6].x = __int_as_float(~(leaf->m_lo));
data[6].y = __int_as_float(0);
}
else {
/* triangle */
data[6].x = __int_as_float(leaf->m_lo);
data[6].y = __int_as_float(leaf->m_hi);
}
memcpy(&pack.nodes[e.idx * BVH_QNODE_SIZE], data, sizeof(float4)*BVH_QNODE_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());
data[7][i] = 0.0f;
}
for(int i = num; i < 4; i++) {
data[0][i] = 0.0f;
data[1][i] = 0.0f;
data[2][i] = 0.0f;
data[3][i] = 0.0f;
data[4][i] = 0.0f;
data[5][i] = 0.0f;
data[6][i] = __int_as_float(0);
data[7][i] = 0.0f;
}
memcpy(&pack.nodes[e.idx * BVH_QNODE_SIZE], data, sizeof(float4)*BVH_QNODE_SIZE);
}
/* Quad SIMD Nodes */
void QBVH::pack_nodes(const array<int>& prims, const BVHNode *root)
{
size_t node_size = root->getSubtreeSize(BVH_STAT_NODE_COUNT);
/* resize arrays */
pack.nodes.clear();
pack.is_leaf.clear();
pack.is_leaf.resize(node_size);
/* 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);
else
pack.nodes.resize(node_size*BVH_QNODE_SIZE);
int nextNodeIdx = 0;
vector<BVHStackEntry> stack;
stack.push_back(BVHStackEntry(root, nextNodeIdx++));
while(stack.size()) {
BVHStackEntry e = stack.back();
stack.pop_back();
pack.is_leaf[e.idx] = e.node->is_leaf();
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++)
stack.push_back(BVHStackEntry(nodes[i], nextNodeIdx++));
/* 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 = (pack.is_leaf[0])? -1: 0;
}
void QBVH::refit_nodes()
{
assert(0); /* todo */
}
CCL_NAMESPACE_END