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test2/source/blender/io/usd/intern/usd_reader_shape.cc
Jesse Yurkovich 2cdbe7b5f3 Fix: USD: Support color attributes on all relevant domains
Color primvars/attributes were historically treated as a special case
for both import and export. This was mostly done to align with how
painting and viewport display works in Blender. Export would generally
ignore color attributes except when they were found on a Mesh's Point or
FaceCorner domains. And import went out of its way to map incoming color
primvars to the FaceCorner domain in more situations than necessary.

To facilitate better roundtripping in Blender<=>USD workflows, and to
reduce code duplication, this PR teaches the common attribute utilities
how to handle color types. The color attributes will now work on all
relevant Mesh and Curve domains.

There were tests in place for this already but they were set to verify
the inverse state, i.e. the technically broken state, until this could
be fixed.

There remains one special case: "displayColor" primvars and attributes.
The "displayColor" is a special primvar in USD and is the de-facto way
to set a simple viewport color in that ecosystem. It must also be a
color3f type. In order to not regress import, if a "displayColor"
primvar is found on the Face domain we will map it to FaceCorner instead
so it can be displayed in the viewport; which has been the case for the
past several releases. We can drop this special-case if/when Blender can
display Face colors through the Viewport Shading "Attribute" color type.
Additionally, Blender will export this, and only this, color attribute
as a color3f.

Note: As was the case prior to this PR, the following 2 discrepancies
still prevent "perfect" round-trips:
- USD does not have an equivalent to Blender's byte colors; they are
  treated as float during IO
- Blender does not have an equivalent to USD's color3 types; they are
  treated as color4 during IO

Pull Request: https://projects.blender.org/blender/blender/pulls/127784
2024-09-24 19:05:55 +02:00

324 lines
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C++

/* SPDX-FileCopyrightText: 2023 Nvidia. All rights reserved.
*
* SPDX-License-Identifier: GPL-2.0-or-later */
#include "BKE_attribute.hh"
#include "BKE_geometry_set.hh"
#include "BKE_lib_id.hh"
#include "BKE_mesh.hh"
#include "BKE_object.hh"
#include "BKE_report.hh"
#include "DNA_modifier_types.h"
#include "DNA_object_types.h"
#include "DNA_windowmanager_types.h"
#include "usd_attribute_utils.hh"
#include "usd_mesh_utils.hh"
#include "usd_reader_shape.hh"
#include <pxr/usd/usdGeom/capsule.h>
#include <pxr/usd/usdGeom/cone.h>
#include <pxr/usd/usdGeom/cube.h>
#include <pxr/usd/usdGeom/cylinder.h>
#include <pxr/usd/usdGeom/sphere.h>
#include <pxr/usdImaging/usdImaging/capsuleAdapter.h>
#include <pxr/usdImaging/usdImaging/coneAdapter.h>
#include <pxr/usdImaging/usdImaging/cubeAdapter.h>
#include <pxr/usdImaging/usdImaging/cylinderAdapter.h>
#include <pxr/usdImaging/usdImaging/sphereAdapter.h>
namespace blender::io::usd {
USDShapeReader::USDShapeReader(const pxr::UsdPrim &prim,
const USDImportParams &import_params,
const ImportSettings &settings)
: USDGeomReader(prim, import_params, settings)
{
}
void USDShapeReader::create_object(Main *bmain, double /*motionSampleTime*/)
{
Mesh *mesh = BKE_mesh_add(bmain, name_.c_str());
object_ = BKE_object_add_only_object(bmain, OB_MESH, name_.c_str());
object_->data = mesh;
}
void USDShapeReader::read_object_data(Main *bmain, double motionSampleTime)
{
const USDMeshReadParams params = create_mesh_read_params(motionSampleTime,
import_params_.mesh_read_flag);
Mesh *mesh = (Mesh *)object_->data;
Mesh *read_mesh = this->read_mesh(mesh, params, nullptr);
if (read_mesh != mesh) {
BKE_mesh_nomain_to_mesh(read_mesh, mesh, object_);
if (is_time_varying()) {
USDGeomReader::add_cache_modifier();
}
}
USDXformReader::read_object_data(bmain, motionSampleTime);
}
template<typename Adapter>
void USDShapeReader::read_values(const double motionSampleTime,
pxr::VtVec3fArray &positions,
pxr::VtIntArray &face_indices,
pxr::VtIntArray &face_counts) const
{
Adapter adapter;
pxr::VtValue points_val = adapter.GetPoints(prim_, motionSampleTime);
if (points_val.IsHolding<pxr::VtVec3fArray>()) {
positions = points_val.Get<pxr::VtVec3fArray>();
}
pxr::VtValue topology_val = adapter.GetTopology(prim_, pxr::SdfPath(), motionSampleTime);
if (topology_val.IsHolding<pxr::HdMeshTopology>()) {
const pxr::HdMeshTopology &topology = topology_val.Get<pxr::HdMeshTopology>();
face_counts = topology.GetFaceVertexCounts();
face_indices = topology.GetFaceVertexIndices();
}
}
bool USDShapeReader::read_mesh_values(double motionSampleTime,
pxr::VtVec3fArray &positions,
pxr::VtIntArray &face_indices,
pxr::VtIntArray &face_counts) const
{
if (prim_.IsA<pxr::UsdGeomCapsule>()) {
read_values<pxr::UsdImagingCapsuleAdapter>(
motionSampleTime, positions, face_indices, face_counts);
return true;
}
if (prim_.IsA<pxr::UsdGeomCylinder>()) {
read_values<pxr::UsdImagingCylinderAdapter>(
motionSampleTime, positions, face_indices, face_counts);
return true;
}
if (prim_.IsA<pxr::UsdGeomCone>()) {
read_values<pxr::UsdImagingConeAdapter>(
motionSampleTime, positions, face_indices, face_counts);
return true;
}
if (prim_.IsA<pxr::UsdGeomCube>()) {
read_values<pxr::UsdImagingCubeAdapter>(
motionSampleTime, positions, face_indices, face_counts);
return true;
}
if (prim_.IsA<pxr::UsdGeomSphere>()) {
read_values<pxr::UsdImagingSphereAdapter>(
motionSampleTime, positions, face_indices, face_counts);
return true;
}
BKE_reportf(reports(),
RPT_ERROR,
"Unhandled Gprim type: %s (%s)",
prim_.GetTypeName().GetText(),
prim_.GetPath().GetText());
return false;
}
Mesh *USDShapeReader::read_mesh(Mesh *existing_mesh,
const USDMeshReadParams params,
const char ** /*r_err_str*/)
{
pxr::VtIntArray face_indices;
pxr::VtIntArray face_counts;
if (!prim_) {
return existing_mesh;
}
/* Should have a good set of data by this point-- copy over. */
Mesh *active_mesh = mesh_from_prim(existing_mesh, params, face_indices, face_counts);
if (active_mesh == existing_mesh) {
return existing_mesh;
}
MutableSpan<int> face_offsets = active_mesh->face_offsets_for_write();
for (const int i : IndexRange(active_mesh->faces_num)) {
face_offsets[i] = face_counts[i];
}
offset_indices::accumulate_counts_to_offsets(face_offsets);
/* Don't smooth-shade cubes; we're not worrying about sharpness for Gprims. */
bke::mesh_smooth_set(*active_mesh, !prim_.IsA<pxr::UsdGeomCube>());
MutableSpan<int> corner_verts = active_mesh->corner_verts_for_write();
for (const int i : corner_verts.index_range()) {
corner_verts[i] = face_indices[i];
}
bke::mesh_calc_edges(*active_mesh, false, false);
return active_mesh;
}
void USDShapeReader::read_geometry(bke::GeometrySet &geometry_set,
USDMeshReadParams params,
const char **r_err_str)
{
Mesh *existing_mesh = geometry_set.get_mesh_for_write();
Mesh *new_mesh = read_mesh(existing_mesh, params, r_err_str);
if (new_mesh != existing_mesh) {
geometry_set.replace_mesh(new_mesh);
}
}
void USDShapeReader::apply_primvars_to_mesh(Mesh *mesh, const double motionSampleTime) const
{
/* TODO: also handle the displayOpacity primvar. */
if (!mesh || !prim_) {
return;
}
pxr::UsdGeomPrimvarsAPI pv_api = pxr::UsdGeomPrimvarsAPI(prim_);
std::vector<pxr::UsdGeomPrimvar> primvars = pv_api.GetPrimvarsWithValues();
pxr::TfToken active_color_name;
for (const pxr::UsdGeomPrimvar &pv : primvars) {
if (!pv.HasValue()) {
BKE_reportf(reports(),
RPT_WARNING,
"Skipping primvar %s, mesh %s -- no value",
pv.GetName().GetText(),
&mesh->id.name[2]);
continue;
}
if (!pv.GetAttr().GetTypeName().IsArray()) {
/* Non-array attributes are technically improper USD. */
continue;
}
const pxr::TfToken name = pxr::UsdGeomPrimvar::StripPrimvarsName(pv.GetPrimvarName());
/* Skip reading primvars that have been read before and are not time varying. */
if (primvar_time_varying_map_.contains(name) && !primvar_time_varying_map_.lookup(name)) {
continue;
}
const pxr::SdfValueTypeName sdf_type = pv.GetTypeName();
const std::optional<eCustomDataType> type = convert_usd_type_to_blender(sdf_type);
if (type == CD_PROP_COLOR) {
/* Set the active color name to 'displayColor', if a color primvar
* with this name exists. Otherwise, use the name of the first
* color primvar we find for the active color. */
if (active_color_name.IsEmpty() || name == usdtokens::displayColor) {
active_color_name = name;
}
}
read_generic_mesh_primvar(mesh, pv, motionSampleTime, false);
/* Record whether the primvar attribute might be time varying. */
if (!primvar_time_varying_map_.contains(name)) {
primvar_time_varying_map_.add(name, pv.ValueMightBeTimeVarying());
}
}
if (!active_color_name.IsEmpty()) {
BKE_id_attributes_default_color_set(&mesh->id, active_color_name.GetText());
BKE_id_attributes_active_color_set(&mesh->id, active_color_name.GetText());
}
}
Mesh *USDShapeReader::mesh_from_prim(Mesh *existing_mesh,
const USDMeshReadParams params,
pxr::VtIntArray &face_indices,
pxr::VtIntArray &face_counts) const
{
pxr::VtVec3fArray positions;
if (!read_mesh_values(params.motion_sample_time, positions, face_indices, face_counts)) {
return existing_mesh;
}
const bool poly_counts_match = existing_mesh ? face_counts.size() == existing_mesh->faces_num :
false;
const bool position_counts_match = existing_mesh ? positions.size() == existing_mesh->verts_num :
false;
Mesh *active_mesh = nullptr;
if (!position_counts_match || !poly_counts_match) {
active_mesh = BKE_mesh_new_nomain_from_template(
existing_mesh, positions.size(), 0, face_counts.size(), face_indices.size());
}
else {
active_mesh = existing_mesh;
}
MutableSpan<float3> vert_positions = active_mesh->vert_positions_for_write();
vert_positions.copy_from(Span(positions.data(), positions.size()).cast<float3>());
if (params.read_flags & MOD_MESHSEQ_READ_COLOR) {
if (active_mesh != existing_mesh) {
/* Clear the primvar map to force attributes to be reloaded. */
this->primvar_time_varying_map_.clear();
}
apply_primvars_to_mesh(active_mesh, params.motion_sample_time);
}
return active_mesh;
}
bool USDShapeReader::is_time_varying()
{
for (const bool animating_flag : primvar_time_varying_map_.values()) {
if (animating_flag) {
return true;
}
}
if (prim_.IsA<pxr::UsdGeomCapsule>()) {
pxr::UsdGeomCapsule geom(prim_);
return (geom.GetAxisAttr().ValueMightBeTimeVarying() ||
geom.GetHeightAttr().ValueMightBeTimeVarying() ||
geom.GetRadiusAttr().ValueMightBeTimeVarying());
}
if (prim_.IsA<pxr::UsdGeomCylinder>()) {
pxr::UsdGeomCylinder geom(prim_);
return (geom.GetAxisAttr().ValueMightBeTimeVarying() ||
geom.GetHeightAttr().ValueMightBeTimeVarying() ||
geom.GetRadiusAttr().ValueMightBeTimeVarying());
}
if (prim_.IsA<pxr::UsdGeomCone>()) {
pxr::UsdGeomCone geom(prim_);
return (geom.GetAxisAttr().ValueMightBeTimeVarying() ||
geom.GetHeightAttr().ValueMightBeTimeVarying() ||
geom.GetRadiusAttr().ValueMightBeTimeVarying());
}
if (prim_.IsA<pxr::UsdGeomCube>()) {
pxr::UsdGeomCube geom(prim_);
return geom.GetSizeAttr().ValueMightBeTimeVarying();
}
if (prim_.IsA<pxr::UsdGeomSphere>()) {
pxr::UsdGeomSphere geom(prim_);
return geom.GetRadiusAttr().ValueMightBeTimeVarying();
}
BKE_reportf(reports(),
RPT_ERROR,
"Unhandled Gprim type: %s (%s)",
prim_.GetTypeName().GetText(),
prim_.GetPath().GetText());
return false;
}
} // namespace blender::io::usd