diff options
author | Hans Goudey <h.goudey@me.com> | 2022-08-31 17:09:01 +0300 |
---|---|---|
committer | Hans Goudey <h.goudey@me.com> | 2022-08-31 17:09:01 +0300 |
commit | f1c0249f34c4171ec311b5b9882e36fed5889259 (patch) | |
tree | 7dd630c9301b8dd468c8279e8c446c62824fb6d6 /source/blender/io/usd | |
parent | 3e73afb5360592fe2bf43419e216035ea3c281f9 (diff) |
Mesh: Move material indices to a generic attribute
This patch moves material indices from the mesh `MPoly` struct to a
generic integer attribute. The builtin material index was already
exposed in geometry nodes, but this makes it a "proper" attribute
accessible with Python and visible in the "Attributes" panel.
The goals of the refactor are code simplification and memory and
performance improvements, mainly because the attribute doesn't have
to be stored and processed if there are no materials. However, until
4.0, material indices will still be read and written in the old
format, meaning there may be a temporary increase in memory usage.
Further notes:
* Completely removing the `MPoly.mat_nr` after 4.0 may require
changes to DNA or introducing a new `MPoly` type.
* Geometry nodes regression tests didn't look at material indices,
so the change reveals a bug in the realize instances node that I fixed.
* Access to material indices from the RNA `MeshPolygon` type is slower
with this patch. The `material_index` attribute can be used instead.
* Cycles is changed to read from the attribute instead.
* BMesh isn't changed in this patch. Theoretically it could be though,
to save 2 bytes per face when less than two materials are used.
* Eventually we could use a 16 bit integer attribute type instead.
Ref T95967
Differential Revision: https://developer.blender.org/D15675
Diffstat (limited to 'source/blender/io/usd')
-rw-r--r-- | source/blender/io/usd/intern/usd_reader_mesh.cc | 27 | ||||
-rw-r--r-- | source/blender/io/usd/intern/usd_reader_mesh.h | 9 | ||||
-rw-r--r-- | source/blender/io/usd/intern/usd_writer_mesh.cc | 15 |
3 files changed, 32 insertions, 19 deletions
diff --git a/source/blender/io/usd/intern/usd_reader_mesh.cc b/source/blender/io/usd/intern/usd_reader_mesh.cc index 94ff24421e2..89a98097780 100644 --- a/source/blender/io/usd/intern/usd_reader_mesh.cc +++ b/source/blender/io/usd/intern/usd_reader_mesh.cc @@ -6,6 +6,7 @@ #include "usd_reader_mesh.h" #include "usd_reader_material.h" +#include "BKE_attribute.hh" #include "BKE_customdata.h" #include "BKE_main.h" #include "BKE_material.h" @@ -319,7 +320,6 @@ void USDMeshReader::read_mpolys(Mesh *mesh) MPoly &poly = mpolys[i]; poly.loopstart = loop_index; poly.totloop = face_size; - poly.mat_nr = 0; /* Polygons are always assumed to be smooth-shaded. If the mesh should be flat-shaded, * this is encoded in custom loop normals. */ @@ -735,10 +735,9 @@ void USDMeshReader::read_mesh_sample(ImportSettings *settings, } } -void USDMeshReader::assign_facesets_to_mpoly(double motionSampleTime, - MPoly *mpoly, - const int /* totpoly */, - std::map<pxr::SdfPath, int> *r_mat_map) +void USDMeshReader::assign_facesets_to_material_indices(double motionSampleTime, + MutableSpan<int> material_indices, + std::map<pxr::SdfPath, int> *r_mat_map) { if (r_mat_map == nullptr) { return; @@ -778,9 +777,8 @@ void USDMeshReader::assign_facesets_to_mpoly(double motionSampleTime, pxr::VtIntArray indices; indicesAttribute.Get(&indices, motionSampleTime); - for (int i = 0; i < indices.size(); i++) { - MPoly &poly = mpoly[indices[i]]; - poly.mat_nr = mat_idx; + for (const int i : indices) { + material_indices[i] = mat_idx; } } } @@ -805,7 +803,12 @@ void USDMeshReader::readFaceSetsSample(Main *bmain, Mesh *mesh, const double mot } std::map<pxr::SdfPath, int> mat_map; - assign_facesets_to_mpoly(motionSampleTime, mesh->mpoly, mesh->totpoly, &mat_map); + + bke::MutableAttributeAccessor attributes = bke::mesh_attributes_for_write(*mesh); + bke::SpanAttributeWriter<int> material_indices = + attributes.lookup_or_add_for_write_only_span<int>("material_index", ATTR_DOMAIN_FACE); + this->assign_facesets_to_material_indices(motionSampleTime, material_indices.span, &mat_map); + material_indices.finish(); /* Build material name map if it's not built yet. */ if (this->settings_->mat_name_to_mat.empty()) { utils::build_mat_map(bmain, &this->settings_->mat_name_to_mat); @@ -911,7 +914,11 @@ Mesh *USDMeshReader::read_mesh(Mesh *existing_mesh, size_t num_polys = active_mesh->totpoly; if (num_polys > 0 && import_params_.import_materials) { std::map<pxr::SdfPath, int> mat_map; - assign_facesets_to_mpoly(motionSampleTime, active_mesh->mpoly, num_polys, &mat_map); + bke::MutableAttributeAccessor attributes = bke::mesh_attributes_for_write(*active_mesh); + bke::SpanAttributeWriter<int> material_indices = + attributes.lookup_or_add_for_write_only_span<int>("material_index", ATTR_DOMAIN_FACE); + assign_facesets_to_material_indices(motionSampleTime, material_indices.span, &mat_map); + material_indices.finish(); } } diff --git a/source/blender/io/usd/intern/usd_reader_mesh.h b/source/blender/io/usd/intern/usd_reader_mesh.h index 5e33ce8b5e8..9a3b0565668 100644 --- a/source/blender/io/usd/intern/usd_reader_mesh.h +++ b/source/blender/io/usd/intern/usd_reader_mesh.h @@ -3,6 +3,8 @@ * Modifications Copyright 2021 Tangent Animation and. NVIDIA Corporation. All rights reserved. */ #pragma once +#include "BLI_span.hh" + #include "usd.h" #include "usd_reader_geom.h" @@ -61,10 +63,9 @@ class USDMeshReader : public USDGeomReader { /** Set USD uniform (per-face) normals as Blender loop normals. */ void process_normals_uniform(Mesh *mesh); void readFaceSetsSample(Main *bmain, Mesh *mesh, double motionSampleTime); - void assign_facesets_to_mpoly(double motionSampleTime, - struct MPoly *mpoly, - int totpoly, - std::map<pxr::SdfPath, int> *r_mat_map); + void assign_facesets_to_material_indices(double motionSampleTime, + MutableSpan<int> material_indices, + std::map<pxr::SdfPath, int> *r_mat_map); void read_mpolys(Mesh *mesh); void read_uvs(Mesh *mesh, double motionSampleTime, bool load_uvs = false); diff --git a/source/blender/io/usd/intern/usd_writer_mesh.cc b/source/blender/io/usd/intern/usd_writer_mesh.cc index b76f74cfd3d..ade75fdb365 100644 --- a/source/blender/io/usd/intern/usd_writer_mesh.cc +++ b/source/blender/io/usd/intern/usd_writer_mesh.cc @@ -11,6 +11,7 @@ #include "BLI_math_vector.h" #include "BKE_attribute.h" +#include "BKE_attribute.hh" #include "BKE_customdata.h" #include "BKE_lib_id.h" #include "BKE_material.h" @@ -255,7 +256,15 @@ static void get_loops_polys(const Mesh *mesh, USDMeshData &usd_mesh_data) { /* Only construct face groups (a.k.a. geometry subsets) when we need them for material * assignments. */ - bool construct_face_groups = mesh->totcol > 1; + const bke::AttributeAccessor attributes = bke::mesh_attributes(*mesh); + const VArray<int> material_indices = attributes.lookup_or_default<int>( + "material_index", ATTR_DOMAIN_FACE, 0); + if (!material_indices.is_single() && mesh->totcol > 1) { + const VArraySpan<int> indices_span(material_indices); + for (const int i : indices_span.index_range()) { + usd_mesh_data.face_groups[indices_span[i]].push_back(i); + } + } usd_mesh_data.face_vertex_counts.reserve(mesh->totpoly); usd_mesh_data.face_indices.reserve(mesh->totloop); @@ -268,10 +277,6 @@ static void get_loops_polys(const Mesh *mesh, USDMeshData &usd_mesh_data) for (int j = 0; j < mpoly->totloop; ++j, ++loop) { usd_mesh_data.face_indices.push_back(loop->v); } - - if (construct_face_groups) { - usd_mesh_data.face_groups[mpoly->mat_nr].push_back(i); - } } } |