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Diffstat (limited to 'intern/cycles/bvh/bvh_build.cpp')
| -rw-r--r-- | intern/cycles/bvh/bvh_build.cpp | 1144 |
1 files changed, 0 insertions, 1144 deletions
diff --git a/intern/cycles/bvh/bvh_build.cpp b/intern/cycles/bvh/bvh_build.cpp deleted file mode 100644 index 025a103d6f8..00000000000 --- a/intern/cycles/bvh/bvh_build.cpp +++ /dev/null @@ -1,1144 +0,0 @@ -/* - * 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 "bvh/bvh_build.h" - -#include "bvh/bvh_binning.h" -#include "bvh/bvh_node.h" -#include "bvh/bvh_params.h" -#include "bvh_split.h" - -#include "render/curves.h" -#include "render/hair.h" -#include "render/mesh.h" -#include "render/object.h" -#include "render/scene.h" - -#include "util/util_algorithm.h" -#include "util/util_foreach.h" -#include "util/util_logging.h" -#include "util/util_progress.h" -#include "util/util_queue.h" -#include "util/util_simd.h" -#include "util/util_stack_allocator.h" -#include "util/util_time.h" - -CCL_NAMESPACE_BEGIN - -/* Constructor / Destructor */ - -BVHBuild::BVHBuild(const vector<Object *> &objects_, - array<int> &prim_type_, - array<int> &prim_index_, - array<int> &prim_object_, - array<float2> &prim_time_, - const BVHParams ¶ms_, - Progress &progress_) - : objects(objects_), - prim_type(prim_type_), - prim_index(prim_index_), - prim_object(prim_object_), - prim_time(prim_time_), - params(params_), - progress(progress_), - progress_start_time(0.0), - unaligned_heuristic(objects_) -{ - spatial_min_overlap = 0.0f; -} - -BVHBuild::~BVHBuild() -{ -} - -/* Adding References */ - -void BVHBuild::add_reference_triangles(BoundBox &root, - BoundBox ¢er, - Mesh *mesh, - int object_index) -{ - const PrimitiveType primitive_type = mesh->primitive_type(); - const Attribute *attr_mP = NULL; - if (mesh->has_motion_blur()) { - attr_mP = mesh->attributes.find(ATTR_STD_MOTION_VERTEX_POSITION); - } - const size_t num_triangles = mesh->num_triangles(); - for (uint j = 0; j < num_triangles; j++) { - Mesh::Triangle t = mesh->get_triangle(j); - const float3 *verts = &mesh->verts[0]; - if (attr_mP == NULL) { - BoundBox bounds = BoundBox::empty; - t.bounds_grow(verts, bounds); - if (bounds.valid() && t.valid(verts)) { - references.push_back(BVHReference(bounds, j, object_index, primitive_type)); - root.grow(bounds); - center.grow(bounds.center2()); - } - } - else if (params.num_motion_triangle_steps == 0 || params.use_spatial_split) { - /* Motion triangles, simple case: single node for the whole - * primitive. Lowest memory footprint and faster BVH build but - * least optimal ray-tracing. - */ - /* TODO(sergey): Support motion steps for spatially split BVH. */ - const size_t num_verts = mesh->verts.size(); - const size_t num_steps = mesh->motion_steps; - const float3 *vert_steps = attr_mP->data_float3(); - BoundBox bounds = BoundBox::empty; - t.bounds_grow(verts, bounds); - for (size_t step = 0; step < num_steps - 1; step++) { - t.bounds_grow(vert_steps + step * num_verts, bounds); - } - if (bounds.valid()) { - references.push_back(BVHReference(bounds, j, object_index, primitive_type)); - root.grow(bounds); - center.grow(bounds.center2()); - } - } - else { - /* Motion triangles, trace optimized case: we split triangle - * primitives into separate nodes for each of the time steps. - * This way we minimize overlap of neighbor curve primitives. - */ - const int num_bvh_steps = params.num_motion_curve_steps * 2 + 1; - const float num_bvh_steps_inv_1 = 1.0f / (num_bvh_steps - 1); - const size_t num_verts = mesh->verts.size(); - const size_t num_steps = mesh->motion_steps; - const float3 *vert_steps = attr_mP->data_float3(); - /* Calculate bounding box of the previous time step. - * Will be reused later to avoid duplicated work on - * calculating BVH time step boundbox. - */ - float3 prev_verts[3]; - t.motion_verts(verts, vert_steps, num_verts, num_steps, 0.0f, prev_verts); - BoundBox prev_bounds = BoundBox::empty; - prev_bounds.grow(prev_verts[0]); - prev_bounds.grow(prev_verts[1]); - prev_bounds.grow(prev_verts[2]); - /* Create all primitive time steps, */ - for (int bvh_step = 1; bvh_step < num_bvh_steps; ++bvh_step) { - const float curr_time = (float)(bvh_step)*num_bvh_steps_inv_1; - float3 curr_verts[3]; - t.motion_verts(verts, vert_steps, num_verts, num_steps, curr_time, curr_verts); - BoundBox curr_bounds = BoundBox::empty; - curr_bounds.grow(curr_verts[0]); - curr_bounds.grow(curr_verts[1]); - curr_bounds.grow(curr_verts[2]); - BoundBox bounds = prev_bounds; - bounds.grow(curr_bounds); - if (bounds.valid()) { - const float prev_time = (float)(bvh_step - 1) * num_bvh_steps_inv_1; - references.push_back( - BVHReference(bounds, j, object_index, primitive_type, prev_time, curr_time)); - root.grow(bounds); - center.grow(bounds.center2()); - } - /* Current time boundbox becomes previous one for the - * next time step. - */ - prev_bounds = curr_bounds; - } - } - } -} - -void BVHBuild::add_reference_curves(BoundBox &root, BoundBox ¢er, Hair *hair, int object_index) -{ - const Attribute *curve_attr_mP = NULL; - if (hair->has_motion_blur()) { - curve_attr_mP = hair->attributes.find(ATTR_STD_MOTION_VERTEX_POSITION); - } - - const PrimitiveType primitive_type = hair->primitive_type(); - - const size_t num_curves = hair->num_curves(); - for (uint j = 0; j < num_curves; j++) { - const Hair::Curve curve = hair->get_curve(j); - const float *curve_radius = &hair->get_curve_radius()[0]; - for (int k = 0; k < curve.num_keys - 1; k++) { - if (curve_attr_mP == NULL) { - /* Really simple logic for static hair. */ - BoundBox bounds = BoundBox::empty; - curve.bounds_grow(k, &hair->get_curve_keys()[0], curve_radius, bounds); - if (bounds.valid()) { - int packed_type = PRIMITIVE_PACK_SEGMENT(primitive_type, k); - references.push_back(BVHReference(bounds, j, object_index, packed_type)); - root.grow(bounds); - center.grow(bounds.center2()); - } - } - else if (params.num_motion_curve_steps == 0 || params.use_spatial_split) { - /* Simple case of motion curves: single node for the while - * shutter time. Lowest memory usage but less optimal - * rendering. - */ - /* TODO(sergey): Support motion steps for spatially split BVH. */ - BoundBox bounds = BoundBox::empty; - curve.bounds_grow(k, &hair->get_curve_keys()[0], curve_radius, bounds); - const size_t num_keys = hair->get_curve_keys().size(); - const size_t num_steps = hair->get_motion_steps(); - const float3 *key_steps = curve_attr_mP->data_float3(); - for (size_t step = 0; step < num_steps - 1; step++) { - curve.bounds_grow(k, key_steps + step * num_keys, curve_radius, bounds); - } - if (bounds.valid()) { - int packed_type = PRIMITIVE_PACK_SEGMENT(primitive_type, k); - references.push_back(BVHReference(bounds, j, object_index, packed_type)); - root.grow(bounds); - center.grow(bounds.center2()); - } - } - else { - /* Motion curves, trace optimized case: we split curve keys - * primitives into separate nodes for each of the time steps. - * This way we minimize overlap of neighbor curve primitives. - */ - const int num_bvh_steps = params.num_motion_curve_steps * 2 + 1; - const float num_bvh_steps_inv_1 = 1.0f / (num_bvh_steps - 1); - const size_t num_steps = hair->get_motion_steps(); - const float3 *curve_keys = &hair->get_curve_keys()[0]; - const float3 *key_steps = curve_attr_mP->data_float3(); - const size_t num_keys = hair->get_curve_keys().size(); - /* Calculate bounding box of the previous time step. - * Will be reused later to avoid duplicated work on - * calculating BVH time step boundbox. - */ - float4 prev_keys[4]; - curve.cardinal_motion_keys(curve_keys, - curve_radius, - key_steps, - num_keys, - num_steps, - 0.0f, - k - 1, - k, - k + 1, - k + 2, - prev_keys); - BoundBox prev_bounds = BoundBox::empty; - curve.bounds_grow(prev_keys, prev_bounds); - /* Create all primitive time steps, */ - for (int bvh_step = 1; bvh_step < num_bvh_steps; ++bvh_step) { - const float curr_time = (float)(bvh_step)*num_bvh_steps_inv_1; - float4 curr_keys[4]; - curve.cardinal_motion_keys(curve_keys, - curve_radius, - key_steps, - num_keys, - num_steps, - curr_time, - k - 1, - k, - k + 1, - k + 2, - curr_keys); - BoundBox curr_bounds = BoundBox::empty; - curve.bounds_grow(curr_keys, curr_bounds); - BoundBox bounds = prev_bounds; - bounds.grow(curr_bounds); - if (bounds.valid()) { - const float prev_time = (float)(bvh_step - 1) * num_bvh_steps_inv_1; - int packed_type = PRIMITIVE_PACK_SEGMENT(primitive_type, k); - references.push_back( - BVHReference(bounds, j, object_index, packed_type, prev_time, curr_time)); - root.grow(bounds); - center.grow(bounds.center2()); - } - /* Current time boundbox becomes previous one for the - * next time step. - */ - prev_bounds = curr_bounds; - } - } - } - } -} - -void BVHBuild::add_reference_geometry(BoundBox &root, - BoundBox ¢er, - Geometry *geom, - int object_index) -{ - if (geom->geometry_type == Geometry::MESH || geom->geometry_type == Geometry::VOLUME) { - Mesh *mesh = static_cast<Mesh *>(geom); - add_reference_triangles(root, center, mesh, object_index); - } - else if (geom->geometry_type == Geometry::HAIR) { - Hair *hair = static_cast<Hair *>(geom); - add_reference_curves(root, center, hair, object_index); - } -} - -void BVHBuild::add_reference_object(BoundBox &root, BoundBox ¢er, Object *ob, int i) -{ - references.push_back(BVHReference(ob->bounds, -1, i, 0)); - root.grow(ob->bounds); - center.grow(ob->bounds.center2()); -} - -static size_t count_curve_segments(Hair *hair) -{ - size_t num = 0, num_curves = hair->num_curves(); - - for (size_t i = 0; i < num_curves; i++) - num += hair->get_curve(i).num_keys - 1; - - return num; -} - -static size_t count_primitives(Geometry *geom) -{ - if (geom->geometry_type == Geometry::MESH || geom->geometry_type == Geometry::VOLUME) { - Mesh *mesh = static_cast<Mesh *>(geom); - return mesh->num_triangles(); - } - else if (geom->geometry_type == Geometry::HAIR) { - Hair *hair = static_cast<Hair *>(geom); - return count_curve_segments(hair); - } - - return 0; -} - -void BVHBuild::add_references(BVHRange &root) -{ - /* reserve space for references */ - size_t num_alloc_references = 0; - - foreach (Object *ob, objects) { - if (params.top_level) { - if (!ob->is_traceable()) { - continue; - } - if (!ob->get_geometry()->is_instanced()) { - num_alloc_references += count_primitives(ob->get_geometry()); - } - else - num_alloc_references++; - } - else { - num_alloc_references += count_primitives(ob->get_geometry()); - } - } - - references.reserve(num_alloc_references); - - /* add references from objects */ - BoundBox bounds = BoundBox::empty, center = BoundBox::empty; - int i = 0; - - foreach (Object *ob, objects) { - if (params.top_level) { - if (!ob->is_traceable()) { - ++i; - continue; - } - if (!ob->get_geometry()->is_instanced()) - add_reference_geometry(bounds, center, ob->get_geometry(), i); - else - add_reference_object(bounds, center, ob, i); - } - else - add_reference_geometry(bounds, center, ob->get_geometry(), i); - - i++; - - if (progress.get_cancel()) - return; - } - - /* happens mostly on empty meshes */ - if (!bounds.valid()) - bounds.grow(zero_float3()); - - root = BVHRange(bounds, center, 0, references.size()); -} - -/* Build */ - -BVHNode *BVHBuild::run() -{ - BVHRange root; - - /* add references */ - add_references(root); - - if (progress.get_cancel()) - return NULL; - - /* init spatial splits */ - if (params.top_level) { - /* NOTE: Technically it is supported by the builder but it's not really - * optimized for speed yet and not really clear yet if it has measurable - * improvement on render time. Needs some extra investigation before - * enabling spatial split for top level BVH. - */ - params.use_spatial_split = false; - } - - spatial_min_overlap = root.bounds().safe_area() * params.spatial_split_alpha; - spatial_free_index = 0; - - need_prim_time = params.num_motion_curve_steps > 0 || params.num_motion_triangle_steps > 0; - - /* init progress updates */ - double build_start_time; - build_start_time = progress_start_time = time_dt(); - progress_count = 0; - progress_total = references.size(); - progress_original_total = progress_total; - - prim_type.resize(references.size()); - prim_index.resize(references.size()); - prim_object.resize(references.size()); - if (need_prim_time) { - prim_time.resize(references.size()); - } - else { - prim_time.resize(0); - } - - /* build recursively */ - BVHNode *rootnode; - - if (params.use_spatial_split) { - /* Perform multithreaded spatial split build. */ - BVHSpatialStorage *local_storage = &spatial_storage.local(); - rootnode = build_node(root, references, 0, local_storage); - task_pool.wait_work(); - } - else { - /* Perform multithreaded binning build. */ - BVHObjectBinning rootbin(root, (references.size()) ? &references[0] : NULL); - rootnode = build_node(rootbin, 0); - task_pool.wait_work(); - } - - /* clean up temporary memory usage by threads */ - spatial_storage.clear(); - - /* delete if we canceled */ - if (rootnode) { - if (progress.get_cancel()) { - rootnode->deleteSubtree(); - rootnode = NULL; - VLOG(1) << "BVH build cancelled."; - } - else { - /*rotate(rootnode, 4, 5);*/ - rootnode->update_visibility(); - rootnode->update_time(); - } - if (rootnode != NULL) { - VLOG(1) << "BVH build statistics:\n" - << " Build time: " << time_dt() - build_start_time << "\n" - << " Total number of nodes: " - << string_human_readable_number(rootnode->getSubtreeSize(BVH_STAT_NODE_COUNT)) - << "\n" - << " Number of inner nodes: " - << string_human_readable_number(rootnode->getSubtreeSize(BVH_STAT_INNER_COUNT)) - << "\n" - << " Number of leaf nodes: " - << string_human_readable_number(rootnode->getSubtreeSize(BVH_STAT_LEAF_COUNT)) - << "\n" - << " Number of unaligned nodes: " - << string_human_readable_number(rootnode->getSubtreeSize(BVH_STAT_UNALIGNED_COUNT)) - << "\n" - << " Allocation slop factor: " - << ((prim_type.capacity() != 0) ? (float)prim_type.size() / prim_type.capacity() : - 1.0f) - << "\n" - << " Maximum depth: " - << string_human_readable_number(rootnode->getSubtreeSize(BVH_STAT_DEPTH)) << "\n"; - } - } - - return rootnode; -} - -void BVHBuild::progress_update() -{ - if (time_dt() - progress_start_time < 0.25) - return; - - double progress_start = (double)progress_count / (double)progress_total; - double duplicates = (double)(progress_total - progress_original_total) / (double)progress_total; - - string msg = string_printf( - "Building BVH %.0f%%, duplicates %.0f%%", progress_start * 100.0, duplicates * 100.0); - - progress.set_substatus(msg); - progress_start_time = time_dt(); -} - -void BVHBuild::thread_build_node(InnerNode *inner, - int child, - const BVHObjectBinning &range, - int level) -{ - if (progress.get_cancel()) - return; - - /* build nodes */ - BVHNode *node = build_node(range, level); - - /* set child in inner node */ - inner->children[child] = node; - - /* update progress */ - if (range.size() < THREAD_TASK_SIZE) { - /*rotate(node, INT_MAX, 5);*/ - - thread_scoped_lock lock(build_mutex); - - progress_count += range.size(); - progress_update(); - } -} - -void BVHBuild::thread_build_spatial_split_node(InnerNode *inner, - int child, - const BVHRange &range, - vector<BVHReference> &references, - int level) -{ - if (progress.get_cancel()) { - return; - } - - /* Get per-thread memory for spatial split. */ - BVHSpatialStorage *local_storage = &spatial_storage.local(); - - /* build nodes */ - BVHNode *node = build_node(range, references, level, local_storage); - - /* set child in inner node */ - inner->children[child] = node; -} - -bool BVHBuild::range_within_max_leaf_size(const BVHRange &range, - const vector<BVHReference> &references) const -{ - size_t size = range.size(); - size_t max_leaf_size = max(params.max_triangle_leaf_size, params.max_curve_leaf_size); - - if (size > max_leaf_size) - return false; - - size_t num_triangles = 0; - size_t num_motion_triangles = 0; - size_t num_curves = 0; - size_t num_motion_curves = 0; - - for (int i = 0; i < size; i++) { - const BVHReference &ref = references[range.start() + i]; - - if (ref.prim_type() & PRIMITIVE_ALL_CURVE) { - if (ref.prim_type() & PRIMITIVE_ALL_MOTION) { - num_motion_curves++; - } - else { - num_curves++; - } - } - else if (ref.prim_type() & PRIMITIVE_ALL_TRIANGLE) { - if (ref.prim_type() & PRIMITIVE_ALL_MOTION) { - num_motion_triangles++; - } - else { - num_triangles++; - } - } - } - - return (num_triangles <= params.max_triangle_leaf_size) && - (num_motion_triangles <= params.max_motion_triangle_leaf_size) && - (num_curves <= params.max_curve_leaf_size) && - (num_motion_curves <= params.max_motion_curve_leaf_size); -} - -/* multithreaded binning builder */ -BVHNode *BVHBuild::build_node(const BVHObjectBinning &range, int level) -{ - size_t size = range.size(); - float leafSAH = params.sah_primitive_cost * range.leafSAH; - float splitSAH = params.sah_node_cost * range.bounds().half_area() + - params.sah_primitive_cost * range.splitSAH; - - /* Have at least one inner node on top level, for performance and correct - * visibility tests, since object instances do not check visibility flag. - */ - if (!(range.size() > 0 && params.top_level && level == 0)) { - /* Make leaf node when threshold reached or SAH tells us. */ - if ((params.small_enough_for_leaf(size, level)) || - (range_within_max_leaf_size(range, references) && leafSAH < splitSAH)) { - return create_leaf_node(range, references); - } - } - - BVHObjectBinning unaligned_range; - float unalignedSplitSAH = FLT_MAX; - float unalignedLeafSAH = FLT_MAX; - Transform aligned_space; - bool do_unalinged_split = false; - if (params.use_unaligned_nodes && splitSAH > params.unaligned_split_threshold * leafSAH) { - aligned_space = unaligned_heuristic.compute_aligned_space(range, &references[0]); - unaligned_range = BVHObjectBinning( - range, &references[0], &unaligned_heuristic, &aligned_space); - unalignedSplitSAH = params.sah_node_cost * unaligned_range.unaligned_bounds().half_area() + - params.sah_primitive_cost * unaligned_range.splitSAH; - unalignedLeafSAH = params.sah_primitive_cost * unaligned_range.leafSAH; - if (!(range.size() > 0 && params.top_level && level == 0)) { - if (unalignedLeafSAH < unalignedSplitSAH && unalignedSplitSAH < splitSAH && - range_within_max_leaf_size(range, references)) { - return create_leaf_node(range, references); - } - } - /* Check whether unaligned split is better than the regular one. */ - if (unalignedSplitSAH < splitSAH) { - do_unalinged_split = true; - } - } - - /* Perform split. */ - BVHObjectBinning left, right; - if (do_unalinged_split) { - unaligned_range.split(&references[0], left, right); - } - else { - range.split(&references[0], left, right); - } - - BoundBox bounds; - if (do_unalinged_split) { - bounds = unaligned_heuristic.compute_aligned_boundbox(range, &references[0], aligned_space); - } - else { - bounds = range.bounds(); - } - - /* Create inner node. */ - InnerNode *inner; - if (range.size() < THREAD_TASK_SIZE) { - /* local build */ - BVHNode *leftnode = build_node(left, level + 1); - BVHNode *rightnode = build_node(right, level + 1); - - inner = new InnerNode(bounds, leftnode, rightnode); - } - else { - /* Threaded build */ - inner = new InnerNode(bounds); - - task_pool.push([=] { thread_build_node(inner, 0, left, level + 1); }); - task_pool.push([=] { thread_build_node(inner, 1, right, level + 1); }); - } - - if (do_unalinged_split) { - inner->set_aligned_space(aligned_space); - } - - return inner; -} - -/* multithreaded spatial split builder */ -BVHNode *BVHBuild::build_node(const BVHRange &range, - vector<BVHReference> &references, - int level, - BVHSpatialStorage *storage) -{ - /* Update progress. - * - * TODO(sergey): Currently it matches old behavior, but we can move it to the - * task thread (which will mimic non=split builder) and save some CPU ticks - * on checking cancel status. - */ - progress_update(); - if (progress.get_cancel()) { - return NULL; - } - - /* Small enough or too deep => create leaf. */ - if (!(range.size() > 0 && params.top_level && level == 0)) { - if (params.small_enough_for_leaf(range.size(), level)) { - progress_count += range.size(); - return create_leaf_node(range, references); - } - } - - /* Perform splitting test. */ - BVHMixedSplit split(this, storage, range, references, level); - - if (!(range.size() > 0 && params.top_level && level == 0)) { - if (split.no_split) { - progress_count += range.size(); - return create_leaf_node(range, references); - } - } - float leafSAH = params.sah_primitive_cost * split.leafSAH; - float splitSAH = params.sah_node_cost * range.bounds().half_area() + - params.sah_primitive_cost * split.nodeSAH; - - BVHMixedSplit unaligned_split; - float unalignedSplitSAH = FLT_MAX; - /* float unalignedLeafSAH = FLT_MAX; */ - Transform aligned_space; - bool do_unalinged_split = false; - if (params.use_unaligned_nodes && splitSAH > params.unaligned_split_threshold * leafSAH) { - aligned_space = unaligned_heuristic.compute_aligned_space(range, &references.at(0)); - unaligned_split = BVHMixedSplit( - this, storage, range, references, level, &unaligned_heuristic, &aligned_space); - /* unalignedLeafSAH = params.sah_primitive_cost * split.leafSAH; */ - unalignedSplitSAH = params.sah_node_cost * unaligned_split.bounds.half_area() + - params.sah_primitive_cost * unaligned_split.nodeSAH; - /* TOOD(sergey): Check we can create leaf already. */ - /* Check whether unaligned split is better than the regular one. */ - if (unalignedSplitSAH < splitSAH) { - do_unalinged_split = true; - } - } - - /* Do split. */ - BVHRange left, right; - if (do_unalinged_split) { - unaligned_split.split(this, left, right, range); - } - else { - split.split(this, left, right, range); - } - - progress_total += left.size() + right.size() - range.size(); - - BoundBox bounds; - if (do_unalinged_split) { - bounds = unaligned_heuristic.compute_aligned_boundbox(range, &references.at(0), aligned_space); - } - else { - bounds = range.bounds(); - } - - /* Create inner node. */ - InnerNode *inner; - if (range.size() < THREAD_TASK_SIZE) { - /* Local build. */ - - /* Build left node. */ - vector<BVHReference> right_references(references.begin() + right.start(), - references.begin() + right.end()); - right.set_start(0); - - BVHNode *leftnode = build_node(left, references, level + 1, storage); - - /* Build right node. */ - BVHNode *rightnode = build_node(right, right_references, level + 1, storage); - - inner = new InnerNode(bounds, leftnode, rightnode); - } - else { - /* Threaded build. */ - inner = new InnerNode(bounds); - - vector<BVHReference> left_references(references.begin() + left.start(), - references.begin() + left.end()); - vector<BVHReference> right_references(references.begin() + right.start(), - references.begin() + right.end()); - right.set_start(0); - - /* Create tasks for left and right nodes, using copy for most arguments and - * move for reference to avoid memory copies. */ - task_pool.push([=, refs = std::move(left_references)]() mutable { - thread_build_spatial_split_node(inner, 0, left, refs, level + 1); - }); - task_pool.push([=, refs = std::move(right_references)]() mutable { - thread_build_spatial_split_node(inner, 1, right, refs, level + 1); - }); - } - - if (do_unalinged_split) { - inner->set_aligned_space(aligned_space); - } - - return inner; -} - -/* Create Nodes */ - -BVHNode *BVHBuild::create_object_leaf_nodes(const BVHReference *ref, int start, int num) -{ - if (num == 0) { - BoundBox bounds = BoundBox::empty; - return new LeafNode(bounds, 0, 0, 0); - } - else if (num == 1) { - assert(start < prim_type.size()); - prim_type[start] = ref->prim_type(); - prim_index[start] = ref->prim_index(); - prim_object[start] = ref->prim_object(); - if (need_prim_time) { - prim_time[start] = make_float2(ref->time_from(), ref->time_to()); - } - - const uint visibility = objects[ref->prim_object()]->visibility_for_tracing(); - BVHNode *leaf_node = new LeafNode(ref->bounds(), visibility, start, start + 1); - leaf_node->time_from = ref->time_from(); - leaf_node->time_to = ref->time_to(); - return leaf_node; - } - else { - int mid = num / 2; - BVHNode *leaf0 = create_object_leaf_nodes(ref, start, mid); - BVHNode *leaf1 = create_object_leaf_nodes(ref + mid, start + mid, num - mid); - - BoundBox bounds = BoundBox::empty; - bounds.grow(leaf0->bounds); - bounds.grow(leaf1->bounds); - - BVHNode *inner_node = new InnerNode(bounds, leaf0, leaf1); - inner_node->time_from = min(leaf0->time_from, leaf1->time_from); - inner_node->time_to = max(leaf0->time_to, leaf1->time_to); - return inner_node; - } -} - -BVHNode *BVHBuild::create_leaf_node(const BVHRange &range, const vector<BVHReference> &references) -{ - /* This is a bit overallocating here (considering leaf size into account), - * but chunk-based re-allocation in vector makes it difficult to use small - * size of stack storage here. Some tweaks are possible tho. - * - * NOTES: - * - If the size is too big, we'll have inefficient stack usage, - * and lots of cache misses. - * - If the size is too small, then we can run out of memory - * allowed to be used by vector. - * In practice it wouldn't mean crash, just allocator will fallback - * to heap which is slower. - * - Optimistic re-allocation in STL could jump us out of stack usage - * because re-allocation happens in chunks and size of those chunks we - * can not control. - */ - typedef StackAllocator<256, int> LeafStackAllocator; - typedef StackAllocator<256, float2> LeafTimeStackAllocator; - typedef StackAllocator<256, BVHReference> LeafReferenceStackAllocator; - - vector<int, LeafStackAllocator> p_type[PRIMITIVE_NUM]; - vector<int, LeafStackAllocator> p_index[PRIMITIVE_NUM]; - vector<int, LeafStackAllocator> p_object[PRIMITIVE_NUM]; - vector<float2, LeafTimeStackAllocator> p_time[PRIMITIVE_NUM]; - vector<BVHReference, LeafReferenceStackAllocator> p_ref[PRIMITIVE_NUM]; - - /* TODO(sergey): In theory we should be able to store references. */ - vector<BVHReference, LeafReferenceStackAllocator> object_references; - - uint visibility[PRIMITIVE_NUM] = {0}; - /* NOTE: Keep initialization in sync with actual number of primitives. */ - BoundBox bounds[PRIMITIVE_NUM] = { - BoundBox::empty, BoundBox::empty, BoundBox::empty, BoundBox::empty}; - int ob_num = 0; - int num_new_prims = 0; - /* Fill in per-type type/index array. */ - for (int i = 0; i < range.size(); i++) { - const BVHReference &ref = references[range.start() + i]; - if (ref.prim_index() != -1) { - uint32_t type_index = bitscan((uint32_t)(ref.prim_type() & PRIMITIVE_ALL)); - p_ref[type_index].push_back(ref); - p_type[type_index].push_back(ref.prim_type()); - p_index[type_index].push_back(ref.prim_index()); - p_object[type_index].push_back(ref.prim_object()); - p_time[type_index].push_back(make_float2(ref.time_from(), ref.time_to())); - - bounds[type_index].grow(ref.bounds()); - visibility[type_index] |= objects[ref.prim_object()]->visibility_for_tracing(); - ++num_new_prims; - } - else { - object_references.push_back(ref); - ++ob_num; - } - } - - /* Create leaf nodes for every existing primitive. - * - * Here we write primitive types, indices and objects to a temporary array. - * This way we keep all the heavy memory allocation code outside of the - * thread lock in the case of spatial split building. - * - * TODO(sergey): With some pointer trickery we can write directly to the - * destination buffers for the non-spatial split BVH. - */ - BVHNode *leaves[PRIMITIVE_NUM + 1] = {NULL}; - int num_leaves = 0; - size_t start_index = 0; - vector<int, LeafStackAllocator> local_prim_type, local_prim_index, local_prim_object; - vector<float2, LeafTimeStackAllocator> local_prim_time; - local_prim_type.resize(num_new_prims); - local_prim_index.resize(num_new_prims); - local_prim_object.resize(num_new_prims); - if (need_prim_time) { - local_prim_time.resize(num_new_prims); - } - for (int i = 0; i < PRIMITIVE_NUM; ++i) { - int num = (int)p_type[i].size(); - if (num != 0) { - assert(p_type[i].size() == p_index[i].size()); - assert(p_type[i].size() == p_object[i].size()); - Transform aligned_space; - bool alignment_found = false; - for (int j = 0; j < num; ++j) { - const int index = start_index + j; - local_prim_type[index] = p_type[i][j]; - local_prim_index[index] = p_index[i][j]; - local_prim_object[index] = p_object[i][j]; - if (need_prim_time) { - local_prim_time[index] = p_time[i][j]; - } - if (params.use_unaligned_nodes && !alignment_found) { - alignment_found = unaligned_heuristic.compute_aligned_space(p_ref[i][j], &aligned_space); - } - } - LeafNode *leaf_node = new LeafNode(bounds[i], visibility[i], start_index, start_index + num); - if (true) { - float time_from = 1.0f, time_to = 0.0f; - for (int j = 0; j < num; ++j) { - const BVHReference &ref = p_ref[i][j]; - time_from = min(time_from, ref.time_from()); - time_to = max(time_to, ref.time_to()); - } - leaf_node->time_from = time_from; - leaf_node->time_to = time_to; - } - if (alignment_found) { - /* Need to recalculate leaf bounds with new alignment. */ - leaf_node->bounds = BoundBox::empty; - for (int j = 0; j < num; ++j) { - const BVHReference &ref = p_ref[i][j]; - BoundBox ref_bounds = unaligned_heuristic.compute_aligned_prim_boundbox(ref, - aligned_space); - leaf_node->bounds.grow(ref_bounds); - } - /* Set alignment space. */ - leaf_node->set_aligned_space(aligned_space); - } - leaves[num_leaves++] = leaf_node; - start_index += num; - } - } - /* Get size of new data to be copied to the packed arrays. */ - const int num_new_leaf_data = start_index; - const size_t new_leaf_data_size = sizeof(int) * num_new_leaf_data; - /* Copy actual data to the packed array. */ - if (params.use_spatial_split) { - spatial_spin_lock.lock(); - /* We use first free index in the packed arrays and mode pointer to the - * end of the current range. - * - * This doesn't give deterministic packed arrays, but it shouldn't really - * matter because order of children in BVH is deterministic. - */ - start_index = spatial_free_index; - spatial_free_index += range.size(); - /* Extend an array when needed. */ - const size_t range_end = start_index + range.size(); - if (prim_type.size() < range_end) { - /* Avoid extra re-allocations by pre-allocating bigger array in an - * advance. - */ - if (range_end >= prim_type.capacity()) { - float progress = (float)progress_count / (float)progress_total; - float factor = (1.0f - progress); - const size_t reserve = (size_t)(range_end + (float)range_end * factor); - prim_type.reserve(reserve); - prim_index.reserve(reserve); - prim_object.reserve(reserve); - if (need_prim_time) { - prim_time.reserve(reserve); - } - } - - prim_type.resize(range_end); - prim_index.resize(range_end); - prim_object.resize(range_end); - if (need_prim_time) { - prim_time.resize(range_end); - } - } - /* Perform actual data copy. */ - if (new_leaf_data_size > 0) { - memcpy(&prim_type[start_index], &local_prim_type[0], new_leaf_data_size); - memcpy(&prim_index[start_index], &local_prim_index[0], new_leaf_data_size); - memcpy(&prim_object[start_index], &local_prim_object[0], new_leaf_data_size); - if (need_prim_time) { - memcpy(&prim_time[start_index], &local_prim_time[0], sizeof(float2) * num_new_leaf_data); - } - } - spatial_spin_lock.unlock(); - } - else { - /* For the regular BVH builder we simply copy new data starting at the - * range start. This is totally thread-safe, all threads are living - * inside of their own range. - */ - start_index = range.start(); - if (new_leaf_data_size > 0) { - memcpy(&prim_type[start_index], &local_prim_type[0], new_leaf_data_size); - memcpy(&prim_index[start_index], &local_prim_index[0], new_leaf_data_size); - memcpy(&prim_object[start_index], &local_prim_object[0], new_leaf_data_size); - if (need_prim_time) { - memcpy(&prim_time[start_index], &local_prim_time[0], sizeof(float2) * num_new_leaf_data); - } - } - } - - /* So far leaves were created with the zero-based index in an arrays, - * here we modify the indices to correspond to actual packed array start - * index. - */ - for (int i = 0; i < num_leaves; ++i) { - LeafNode *leaf = (LeafNode *)leaves[i]; - leaf->lo += start_index; - leaf->hi += start_index; - } - - /* Create leaf node for object. */ - if (num_leaves == 0 || ob_num) { - /* Only create object leaf nodes if there are objects or no other - * nodes created. - */ - const BVHReference *ref = (ob_num) ? &object_references[0] : NULL; - leaves[num_leaves] = create_object_leaf_nodes(ref, start_index + num_new_leaf_data, ob_num); - ++num_leaves; - } - - /* TODO(sergey): Need to take care of alignment when number of leaves - * is more than 1. - */ - if (num_leaves == 1) { - /* Simplest case: single leaf, just return it. - * In all the rest cases we'll be creating intermediate inner node with - * an appropriate bounding box. - */ - return leaves[0]; - } - else if (num_leaves == 2) { - return new InnerNode(range.bounds(), leaves[0], leaves[1]); - } - else if (num_leaves == 3) { - BoundBox inner_bounds = merge(leaves[1]->bounds, leaves[2]->bounds); - BVHNode *inner = new InnerNode(inner_bounds, leaves[1], leaves[2]); - return new InnerNode(range.bounds(), leaves[0], inner); - } - else { - /* Should be doing more branches if more primitive types added. */ - assert(num_leaves <= 5); - BoundBox inner_bounds_a = merge(leaves[0]->bounds, leaves[1]->bounds); - BoundBox inner_bounds_b = merge(leaves[2]->bounds, leaves[3]->bounds); - BVHNode *inner_a = new InnerNode(inner_bounds_a, leaves[0], leaves[1]); - BVHNode *inner_b = new InnerNode(inner_bounds_b, leaves[2], leaves[3]); - BoundBox inner_bounds_c = merge(inner_a->bounds, inner_b->bounds); - BVHNode *inner_c = new InnerNode(inner_bounds_c, inner_a, inner_b); - if (num_leaves == 5) { - return new InnerNode(range.bounds(), inner_c, leaves[4]); - } - return inner_c; - } - -#undef MAX_ITEMS_PER_LEAF -} - -/* Tree Rotations */ - -void BVHBuild::rotate(BVHNode *node, int max_depth, int iterations) -{ - /* in tested scenes, this resulted in slightly slower raytracing, so disabled - * it for now. could be implementation bug, or depend on the scene */ - if (node) - for (int i = 0; i < iterations; i++) - rotate(node, max_depth); -} - -void BVHBuild::rotate(BVHNode *node, int max_depth) -{ - /* nothing to rotate if we reached a leaf node. */ - if (node->is_leaf() || max_depth < 0) - return; - - InnerNode *parent = (InnerNode *)node; - - /* rotate all children first */ - for (size_t c = 0; c < 2; c++) - rotate(parent->children[c], max_depth - 1); - - /* compute current area of all children */ - BoundBox bounds0 = parent->children[0]->bounds; - BoundBox bounds1 = parent->children[1]->bounds; - - float area0 = bounds0.half_area(); - float area1 = bounds1.half_area(); - float4 child_area = make_float4(area0, area1, 0.0f, 0.0f); - - /* find best rotation. we pick a target child of a first child, and swap - * this with an other child. we perform the best such swap. */ - float best_cost = FLT_MAX; - int best_child = -1, best_target = -1, best_other = -1; - - for (size_t c = 0; c < 2; c++) { - /* ignore leaf nodes as we cannot descent into */ - if (parent->children[c]->is_leaf()) - continue; - - InnerNode *child = (InnerNode *)parent->children[c]; - BoundBox &other = (c == 0) ? bounds1 : bounds0; - - /* transpose child bounds */ - BoundBox target0 = child->children[0]->bounds; - BoundBox target1 = child->children[1]->bounds; - - /* compute cost for both possible swaps */ - float cost0 = merge(other, target1).half_area() - child_area[c]; - float cost1 = merge(target0, other).half_area() - child_area[c]; - - if (min(cost0, cost1) < best_cost) { - best_child = (int)c; - best_other = (int)(1 - c); - - if (cost0 < cost1) { - best_cost = cost0; - best_target = 0; - } - else { - best_cost = cost0; - best_target = 1; - } - } - } - - /* if we did not find a swap that improves the SAH then do nothing */ - if (best_cost >= 0) - return; - - assert(best_child == 0 || best_child == 1); - assert(best_target != -1); - - /* perform the best found tree rotation */ - InnerNode *child = (InnerNode *)parent->children[best_child]; - - swap(parent->children[best_other], child->children[best_target]); - child->bounds = merge(child->children[0]->bounds, child->children[1]->bounds); -} - -CCL_NAMESPACE_END |