diff options
author | Hans Goudey <h.goudey@me.com> | 2021-10-26 19:25:44 +0300 |
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committer | Hans Goudey <h.goudey@me.com> | 2021-10-26 19:25:44 +0300 |
commit | 8ddfdfd2b2a52f746312246aa3099ab0df8544a0 (patch) | |
tree | 5b228cb84c3587661a9c5b59878ebc6f99f07dd5 /source/blender/blenkernel/intern/volume_to_mesh.cc | |
parent | 7979dff9dc7985cebb530c7490dc730d9c1acf1d (diff) |
Geometry Nodes: Handle multiple grids in the volume to mesh node
In future use cases, a volume can contain many grids that represent the
density information. In this case, it's better if the volume to mesh node
creates a mesh based on all of the grids in the volume.
This is also a benefit to share-ability, since one doesn't have to
specify the grid name in the node. Instead, in the future we can have
a way to split particular grids into separate volumes, if only one
grid should be considered.
The code changes are relatively simple:
- Move the old volume to mesh node to the legacy folder.
- Run the volume to mesh node on all instance geometry, like elsewhere.
- Make the blenkernel's volume to mesh API a bit more specific.
Differential Revision: https://developer.blender.org/D12997
Diffstat (limited to 'source/blender/blenkernel/intern/volume_to_mesh.cc')
-rw-r--r-- | source/blender/blenkernel/intern/volume_to_mesh.cc | 93 |
1 files changed, 63 insertions, 30 deletions
diff --git a/source/blender/blenkernel/intern/volume_to_mesh.cc b/source/blender/blenkernel/intern/volume_to_mesh.cc index e9d6eea4614..6e465b2fdf0 100644 --- a/source/blender/blenkernel/intern/volume_to_mesh.cc +++ b/source/blender/blenkernel/intern/volume_to_mesh.cc @@ -121,46 +121,66 @@ struct VolumeToMeshOp { } }; -static Mesh *new_mesh_from_openvdb_data(Span<openvdb::Vec3s> verts, - Span<openvdb::Vec3I> tris, - Span<openvdb::Vec4I> quads) +/** + * Convert mesh data from the format provided by OpenVDB into Blender's #Mesh data structure. + * This can be used to add mesh data from a grid into an existing mesh rather than merging multiple + * meshes later on. + */ +void fill_mesh_from_openvdb_data(const Span<openvdb::Vec3s> vdb_verts, + const Span<openvdb::Vec3I> vdb_tris, + const Span<openvdb::Vec4I> vdb_quads, + const int vert_offset, + const int poly_offset, + const int loop_offset, + MutableSpan<MVert> verts, + MutableSpan<MPoly> polys, + MutableSpan<MLoop> loops) { - const int tot_loops = 3 * tris.size() + 4 * quads.size(); - const int tot_polys = tris.size() + quads.size(); - - Mesh *mesh = BKE_mesh_new_nomain(verts.size(), 0, 0, tot_loops, tot_polys); - /* Write vertices. */ - for (const int i : verts.index_range()) { - const blender::float3 co = blender::float3(verts[i].asV()); - copy_v3_v3(mesh->mvert[i].co, co); + for (const int i : vdb_verts.index_range()) { + const blender::float3 co = blender::float3(vdb_verts[i].asV()); + copy_v3_v3(verts[vert_offset + i].co, co); } /* Write triangles. */ - for (const int i : tris.index_range()) { - mesh->mpoly[i].loopstart = 3 * i; - mesh->mpoly[i].totloop = 3; + for (const int i : vdb_tris.index_range()) { + polys[poly_offset + i].loopstart = loop_offset + 3 * i; + polys[poly_offset + i].totloop = 3; for (int j = 0; j < 3; j++) { /* Reverse vertex order to get correct normals. */ - mesh->mloop[3 * i + j].v = tris[i][2 - j]; + loops[loop_offset + 3 * i + j].v = vert_offset + vdb_tris[i][2 - j]; } } /* Write quads. */ - const int poly_offset = tris.size(); - const int loop_offset = tris.size() * 3; - for (const int i : quads.index_range()) { - mesh->mpoly[poly_offset + i].loopstart = loop_offset + 4 * i; - mesh->mpoly[poly_offset + i].totloop = 4; + const int quad_offset = poly_offset + vdb_tris.size(); + const int quad_loop_offset = loop_offset + vdb_tris.size() * 3; + for (const int i : vdb_quads.index_range()) { + polys[quad_offset + i].loopstart = quad_loop_offset + 4 * i; + polys[quad_offset + i].totloop = 4; for (int j = 0; j < 4; j++) { /* Reverse vertex order to get correct normals. */ - mesh->mloop[loop_offset + 4 * i + j].v = quads[i][3 - j]; + loops[quad_loop_offset + 4 * i + j].v = vert_offset + vdb_quads[i][3 - j]; } } +} - BKE_mesh_calc_edges(mesh, false, false); - BKE_mesh_normals_tag_dirty(mesh); - return mesh; +/** + * Convert an OpenVDB volume grid to corresponding mesh data: vertex positions and quad and + * triangle indices. + */ +bke::OpenVDBMeshData volume_to_mesh_data(const openvdb::GridBase &grid, + const VolumeToMeshResolution &resolution, + const float threshold, + const float adaptivity) +{ + const VolumeGridType grid_type = BKE_volume_grid_type_openvdb(grid); + + VolumeToMeshOp to_mesh_op{grid, resolution, threshold, adaptivity}; + if (!BKE_volume_grid_type_operation(grid_type, to_mesh_op)) { + return {}; + } + return {std::move(to_mesh_op.verts), std::move(to_mesh_op.tris), std::move(to_mesh_op.quads)}; } Mesh *volume_to_mesh(const openvdb::GridBase &grid, @@ -168,14 +188,27 @@ Mesh *volume_to_mesh(const openvdb::GridBase &grid, const float threshold, const float adaptivity) { - const VolumeGridType grid_type = BKE_volume_grid_type_openvdb(grid); + const bke::OpenVDBMeshData mesh_data = volume_to_mesh_data( + grid, resolution, threshold, adaptivity); + + const int tot_loops = 3 * mesh_data.tris.size() + 4 * mesh_data.quads.size(); + const int tot_polys = mesh_data.tris.size() + mesh_data.quads.size(); + Mesh *mesh = BKE_mesh_new_nomain(mesh_data.verts.size(), 0, 0, tot_loops, tot_polys); + + fill_mesh_from_openvdb_data(mesh_data.verts, + mesh_data.tris, + mesh_data.quads, + 0, + 0, + 0, + {mesh->mvert, mesh->totvert}, + {mesh->mpoly, mesh->totpoly}, + {mesh->mloop, mesh->totloop}); - VolumeToMeshOp to_mesh_op{grid, resolution, threshold, adaptivity}; - if (!BKE_volume_grid_type_operation(grid_type, to_mesh_op)) { - return nullptr; - } + BKE_mesh_calc_edges(mesh, false, false); + BKE_mesh_normals_tag_dirty(mesh); - return new_mesh_from_openvdb_data(to_mesh_op.verts, to_mesh_op.tris, to_mesh_op.quads); + return mesh; } #endif /* WITH_OPENVDB */ |