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Diffstat (limited to 'intern/cycles/bvh/split.cpp')
| -rw-r--r-- | intern/cycles/bvh/split.cpp | 518 |
1 files changed, 518 insertions, 0 deletions
diff --git a/intern/cycles/bvh/split.cpp b/intern/cycles/bvh/split.cpp new file mode 100644 index 00000000000..102c50e2979 --- /dev/null +++ b/intern/cycles/bvh/split.cpp @@ -0,0 +1,518 @@ +/* + * 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/split.h" + +#include "bvh/build.h" +#include "bvh/sort.h" + +#include "scene/hair.h" +#include "scene/mesh.h" +#include "scene/object.h" + +#include "util/algorithm.h" + +CCL_NAMESPACE_BEGIN + +/* Object Split */ + +BVHObjectSplit::BVHObjectSplit(BVHBuild *builder, + BVHSpatialStorage *storage, + const BVHRange &range, + vector<BVHReference> &references, + float nodeSAH, + const BVHUnaligned *unaligned_heuristic, + const Transform *aligned_space) + : sah(FLT_MAX), + dim(0), + num_left(0), + left_bounds(BoundBox::empty), + right_bounds(BoundBox::empty), + storage_(storage), + references_(&references), + unaligned_heuristic_(unaligned_heuristic), + aligned_space_(aligned_space) +{ + const BVHReference *ref_ptr = &references_->at(range.start()); + float min_sah = FLT_MAX; + + storage_->right_bounds.resize(range.size()); + + for (int dim = 0; dim < 3; dim++) { + /* Sort references. */ + bvh_reference_sort(range.start(), + range.end(), + &references_->at(0), + dim, + unaligned_heuristic_, + aligned_space_); + + /* sweep right to left and determine bounds. */ + BoundBox right_bounds = BoundBox::empty; + for (int i = range.size() - 1; i > 0; i--) { + BoundBox prim_bounds = get_prim_bounds(ref_ptr[i]); + right_bounds.grow(prim_bounds); + storage_->right_bounds[i - 1] = right_bounds; + } + + /* sweep left to right and select lowest SAH. */ + BoundBox left_bounds = BoundBox::empty; + + for (int i = 1; i < range.size(); i++) { + BoundBox prim_bounds = get_prim_bounds(ref_ptr[i - 1]); + left_bounds.grow(prim_bounds); + right_bounds = storage_->right_bounds[i - 1]; + + float sah = nodeSAH + left_bounds.safe_area() * builder->params.primitive_cost(i) + + right_bounds.safe_area() * builder->params.primitive_cost(range.size() - i); + + if (sah < min_sah) { + min_sah = sah; + + this->sah = sah; + this->dim = dim; + this->num_left = i; + this->left_bounds = left_bounds; + this->right_bounds = right_bounds; + } + } + } +} + +void BVHObjectSplit::split(BVHRange &left, BVHRange &right, const BVHRange &range) +{ + assert(references_->size() > 0); + /* sort references according to split */ + bvh_reference_sort(range.start(), + range.end(), + &references_->at(0), + this->dim, + unaligned_heuristic_, + aligned_space_); + + BoundBox effective_left_bounds, effective_right_bounds; + const int num_right = range.size() - this->num_left; + if (aligned_space_ == NULL) { + effective_left_bounds = left_bounds; + effective_right_bounds = right_bounds; + } + else { + effective_left_bounds = BoundBox::empty; + effective_right_bounds = BoundBox::empty; + for (int i = 0; i < this->num_left; ++i) { + BoundBox prim_boundbox = references_->at(range.start() + i).bounds(); + effective_left_bounds.grow(prim_boundbox); + } + for (int i = 0; i < num_right; ++i) { + BoundBox prim_boundbox = references_->at(range.start() + this->num_left + i).bounds(); + effective_right_bounds.grow(prim_boundbox); + } + } + + /* split node ranges */ + left = BVHRange(effective_left_bounds, range.start(), this->num_left); + right = BVHRange(effective_right_bounds, left.end(), num_right); +} + +/* Spatial Split */ + +BVHSpatialSplit::BVHSpatialSplit(const BVHBuild &builder, + BVHSpatialStorage *storage, + const BVHRange &range, + vector<BVHReference> &references, + float nodeSAH, + const BVHUnaligned *unaligned_heuristic, + const Transform *aligned_space) + : sah(FLT_MAX), + dim(0), + pos(0.0f), + storage_(storage), + references_(&references), + unaligned_heuristic_(unaligned_heuristic), + aligned_space_(aligned_space) +{ + /* initialize bins. */ + BoundBox range_bounds; + if (aligned_space == NULL) { + range_bounds = range.bounds(); + } + else { + range_bounds = unaligned_heuristic->compute_aligned_boundbox( + range, &references_->at(0), *aligned_space); + } + + float3 origin = range_bounds.min; + float3 binSize = (range_bounds.max - origin) * (1.0f / (float)BVHParams::NUM_SPATIAL_BINS); + float3 invBinSize = 1.0f / binSize; + + for (int dim = 0; dim < 3; dim++) { + for (int i = 0; i < BVHParams::NUM_SPATIAL_BINS; i++) { + BVHSpatialBin &bin = storage_->bins[dim][i]; + + bin.bounds = BoundBox::empty; + bin.enter = 0; + bin.exit = 0; + } + } + + /* chop references into bins. */ + for (unsigned int refIdx = range.start(); refIdx < range.end(); refIdx++) { + const BVHReference &ref = references_->at(refIdx); + BoundBox prim_bounds = get_prim_bounds(ref); + float3 firstBinf = (prim_bounds.min - origin) * invBinSize; + float3 lastBinf = (prim_bounds.max - origin) * invBinSize; + int3 firstBin = make_int3((int)firstBinf.x, (int)firstBinf.y, (int)firstBinf.z); + int3 lastBin = make_int3((int)lastBinf.x, (int)lastBinf.y, (int)lastBinf.z); + + firstBin = clamp(firstBin, 0, BVHParams::NUM_SPATIAL_BINS - 1); + lastBin = clamp(lastBin, firstBin, BVHParams::NUM_SPATIAL_BINS - 1); + + for (int dim = 0; dim < 3; dim++) { + BVHReference currRef( + get_prim_bounds(ref), ref.prim_index(), ref.prim_object(), ref.prim_type()); + + for (int i = firstBin[dim]; i < lastBin[dim]; i++) { + BVHReference leftRef, rightRef; + + split_reference( + builder, leftRef, rightRef, currRef, dim, origin[dim] + binSize[dim] * (float)(i + 1)); + storage_->bins[dim][i].bounds.grow(leftRef.bounds()); + currRef = rightRef; + } + + storage_->bins[dim][lastBin[dim]].bounds.grow(currRef.bounds()); + storage_->bins[dim][firstBin[dim]].enter++; + storage_->bins[dim][lastBin[dim]].exit++; + } + } + + /* select best split plane. */ + storage_->right_bounds.resize(BVHParams::NUM_SPATIAL_BINS); + for (int dim = 0; dim < 3; dim++) { + /* sweep right to left and determine bounds. */ + BoundBox right_bounds = BoundBox::empty; + for (int i = BVHParams::NUM_SPATIAL_BINS - 1; i > 0; i--) { + right_bounds.grow(storage_->bins[dim][i].bounds); + storage_->right_bounds[i - 1] = right_bounds; + } + + /* sweep left to right and select lowest SAH. */ + BoundBox left_bounds = BoundBox::empty; + int leftNum = 0; + int rightNum = range.size(); + + for (int i = 1; i < BVHParams::NUM_SPATIAL_BINS; i++) { + left_bounds.grow(storage_->bins[dim][i - 1].bounds); + leftNum += storage_->bins[dim][i - 1].enter; + rightNum -= storage_->bins[dim][i - 1].exit; + + float sah = nodeSAH + left_bounds.safe_area() * builder.params.primitive_cost(leftNum) + + storage_->right_bounds[i - 1].safe_area() * + builder.params.primitive_cost(rightNum); + + if (sah < this->sah) { + this->sah = sah; + this->dim = dim; + this->pos = origin[dim] + binSize[dim] * (float)i; + } + } + } +} + +void BVHSpatialSplit::split(BVHBuild *builder, + BVHRange &left, + BVHRange &right, + const BVHRange &range) +{ + /* Categorize references and compute bounds. + * + * Left-hand side: [left_start, left_end[ + * Uncategorized/split: [left_end, right_start[ + * Right-hand side: [right_start, refs.size()[ */ + + vector<BVHReference> &refs = *references_; + int left_start = range.start(); + int left_end = left_start; + int right_start = range.end(); + int right_end = range.end(); + BoundBox left_bounds = BoundBox::empty; + BoundBox right_bounds = BoundBox::empty; + + for (int i = left_end; i < right_start; i++) { + BoundBox prim_bounds = get_prim_bounds(refs[i]); + if (prim_bounds.max[this->dim] <= this->pos) { + /* entirely on the left-hand side */ + left_bounds.grow(prim_bounds); + swap(refs[i], refs[left_end++]); + } + else if (prim_bounds.min[this->dim] >= this->pos) { + /* entirely on the right-hand side */ + right_bounds.grow(prim_bounds); + swap(refs[i--], refs[--right_start]); + } + } + + /* Duplicate or unsplit references intersecting both sides. + * + * Duplication happens into a temporary pre-allocated vector in order to + * reduce number of memmove() calls happening in vector.insert(). + */ + vector<BVHReference> &new_refs = storage_->new_references; + new_refs.clear(); + new_refs.reserve(right_start - left_end); + while (left_end < right_start) { + /* split reference. */ + BVHReference curr_ref(get_prim_bounds(refs[left_end]), + refs[left_end].prim_index(), + refs[left_end].prim_object(), + refs[left_end].prim_type()); + BVHReference lref, rref; + split_reference(*builder, lref, rref, curr_ref, this->dim, this->pos); + + /* compute SAH for duplicate/unsplit candidates. */ + BoundBox lub = left_bounds; // Unsplit to left: new left-hand bounds. + BoundBox rub = right_bounds; // Unsplit to right: new right-hand bounds. + BoundBox ldb = left_bounds; // Duplicate: new left-hand bounds. + BoundBox rdb = right_bounds; // Duplicate: new right-hand bounds. + + lub.grow(curr_ref.bounds()); + rub.grow(curr_ref.bounds()); + ldb.grow(lref.bounds()); + rdb.grow(rref.bounds()); + + float lac = builder->params.primitive_cost(left_end - left_start); + float rac = builder->params.primitive_cost(right_end - right_start); + float lbc = builder->params.primitive_cost(left_end - left_start + 1); + float rbc = builder->params.primitive_cost(right_end - right_start + 1); + + float unsplitLeftSAH = lub.safe_area() * lbc + right_bounds.safe_area() * rac; + float unsplitRightSAH = left_bounds.safe_area() * lac + rub.safe_area() * rbc; + float duplicateSAH = ldb.safe_area() * lbc + rdb.safe_area() * rbc; + float minSAH = min(min(unsplitLeftSAH, unsplitRightSAH), duplicateSAH); + + if (minSAH == unsplitLeftSAH) { + /* unsplit to left */ + left_bounds = lub; + left_end++; + } + else if (minSAH == unsplitRightSAH) { + /* unsplit to right */ + right_bounds = rub; + swap(refs[left_end], refs[--right_start]); + } + else { + /* duplicate */ + left_bounds = ldb; + right_bounds = rdb; + refs[left_end++] = lref; + new_refs.push_back(rref); + right_end++; + } + } + /* Insert duplicated references into actual array in one go. */ + if (new_refs.size() != 0) { + refs.insert(refs.begin() + (right_end - new_refs.size()), new_refs.begin(), new_refs.end()); + } + if (aligned_space_ != NULL) { + left_bounds = right_bounds = BoundBox::empty; + for (int i = left_start; i < left_end - left_start; ++i) { + BoundBox prim_boundbox = references_->at(i).bounds(); + left_bounds.grow(prim_boundbox); + } + for (int i = right_start; i < right_end - right_start; ++i) { + BoundBox prim_boundbox = references_->at(i).bounds(); + right_bounds.grow(prim_boundbox); + } + } + left = BVHRange(left_bounds, left_start, left_end - left_start); + right = BVHRange(right_bounds, right_start, right_end - right_start); +} + +void BVHSpatialSplit::split_triangle_primitive(const Mesh *mesh, + const Transform *tfm, + int prim_index, + int dim, + float pos, + BoundBox &left_bounds, + BoundBox &right_bounds) +{ + Mesh::Triangle t = mesh->get_triangle(prim_index); + const float3 *verts = &mesh->verts[0]; + float3 v1 = tfm ? transform_point(tfm, verts[t.v[2]]) : verts[t.v[2]]; + v1 = get_unaligned_point(v1); + + for (int i = 0; i < 3; i++) { + float3 v0 = v1; + int vindex = t.v[i]; + v1 = tfm ? transform_point(tfm, verts[vindex]) : verts[vindex]; + v1 = get_unaligned_point(v1); + float v0p = v0[dim]; + float v1p = v1[dim]; + + /* insert vertex to the boxes it belongs to. */ + if (v0p <= pos) + left_bounds.grow(v0); + + if (v0p >= pos) + right_bounds.grow(v0); + + /* edge intersects the plane => insert intersection to both boxes. */ + if ((v0p < pos && v1p > pos) || (v0p > pos && v1p < pos)) { + float3 t = lerp(v0, v1, clamp((pos - v0p) / (v1p - v0p), 0.0f, 1.0f)); + left_bounds.grow(t); + right_bounds.grow(t); + } + } +} + +void BVHSpatialSplit::split_curve_primitive(const Hair *hair, + const Transform *tfm, + int prim_index, + int segment_index, + int dim, + float pos, + BoundBox &left_bounds, + BoundBox &right_bounds) +{ + /* curve split: NOTE - Currently ignores curve width and needs to be fixed. */ + Hair::Curve curve = hair->get_curve(prim_index); + const int k0 = curve.first_key + segment_index; + const int k1 = k0 + 1; + float3 v0 = hair->get_curve_keys()[k0]; + float3 v1 = hair->get_curve_keys()[k1]; + + if (tfm != NULL) { + v0 = transform_point(tfm, v0); + v1 = transform_point(tfm, v1); + } + v0 = get_unaligned_point(v0); + v1 = get_unaligned_point(v1); + + float v0p = v0[dim]; + float v1p = v1[dim]; + + /* insert vertex to the boxes it belongs to. */ + if (v0p <= pos) + left_bounds.grow(v0); + + if (v0p >= pos) + right_bounds.grow(v0); + + if (v1p <= pos) + left_bounds.grow(v1); + + if (v1p >= pos) + right_bounds.grow(v1); + + /* edge intersects the plane => insert intersection to both boxes. */ + if ((v0p < pos && v1p > pos) || (v0p > pos && v1p < pos)) { + float3 t = lerp(v0, v1, clamp((pos - v0p) / (v1p - v0p), 0.0f, 1.0f)); + left_bounds.grow(t); + right_bounds.grow(t); + } +} + +void BVHSpatialSplit::split_triangle_reference(const BVHReference &ref, + const Mesh *mesh, + int dim, + float pos, + BoundBox &left_bounds, + BoundBox &right_bounds) +{ + split_triangle_primitive(mesh, NULL, ref.prim_index(), dim, pos, left_bounds, right_bounds); +} + +void BVHSpatialSplit::split_curve_reference(const BVHReference &ref, + const Hair *hair, + int dim, + float pos, + BoundBox &left_bounds, + BoundBox &right_bounds) +{ + split_curve_primitive(hair, + NULL, + ref.prim_index(), + PRIMITIVE_UNPACK_SEGMENT(ref.prim_type()), + dim, + pos, + left_bounds, + right_bounds); +} + +void BVHSpatialSplit::split_object_reference( + const Object *object, int dim, float pos, BoundBox &left_bounds, BoundBox &right_bounds) +{ + Geometry *geom = object->get_geometry(); + + if (geom->geometry_type == Geometry::MESH || geom->geometry_type == Geometry::VOLUME) { + Mesh *mesh = static_cast<Mesh *>(geom); + for (int tri_idx = 0; tri_idx < mesh->num_triangles(); ++tri_idx) { + split_triangle_primitive( + mesh, &object->get_tfm(), tri_idx, dim, pos, left_bounds, right_bounds); + } + } + else if (geom->geometry_type == Geometry::HAIR) { + Hair *hair = static_cast<Hair *>(geom); + for (int curve_idx = 0; curve_idx < hair->num_curves(); ++curve_idx) { + Hair::Curve curve = hair->get_curve(curve_idx); + for (int segment_idx = 0; segment_idx < curve.num_keys - 1; ++segment_idx) { + split_curve_primitive( + hair, &object->get_tfm(), curve_idx, segment_idx, dim, pos, left_bounds, right_bounds); + } + } + } +} + +void BVHSpatialSplit::split_reference(const BVHBuild &builder, + BVHReference &left, + BVHReference &right, + const BVHReference &ref, + int dim, + float pos) +{ + /* initialize boundboxes */ + BoundBox left_bounds = BoundBox::empty; + BoundBox right_bounds = BoundBox::empty; + + /* loop over vertices/edges. */ + const Object *ob = builder.objects[ref.prim_object()]; + + if (ref.prim_type() & PRIMITIVE_ALL_TRIANGLE) { + Mesh *mesh = static_cast<Mesh *>(ob->get_geometry()); + split_triangle_reference(ref, mesh, dim, pos, left_bounds, right_bounds); + } + else if (ref.prim_type() & PRIMITIVE_ALL_CURVE) { + Hair *hair = static_cast<Hair *>(ob->get_geometry()); + split_curve_reference(ref, hair, dim, pos, left_bounds, right_bounds); + } + else { + split_object_reference(ob, dim, pos, left_bounds, right_bounds); + } + + /* intersect with original bounds. */ + left_bounds.max[dim] = pos; + right_bounds.min[dim] = pos; + + left_bounds.intersect(ref.bounds()); + right_bounds.intersect(ref.bounds()); + + /* set references */ + left = BVHReference(left_bounds, ref.prim_index(), ref.prim_object(), ref.prim_type()); + right = BVHReference(right_bounds, ref.prim_index(), ref.prim_object(), ref.prim_type()); +} + +CCL_NAMESPACE_END |