diff options
author | Michael Kowalski <makowalski> | 2021-08-03 12:55:53 +0300 |
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committer | Sybren A. Stüvel <sybren@blender.org> | 2021-08-03 13:33:36 +0300 |
commit | ea54cbe1b42efb3107285c89685f555c06997062 (patch) | |
tree | bfaf0cb2315172e330c982ae081a4299cc3dc82b /source/blender/io/usd/intern/usd_reader_material.h | |
parent | 28b9dd7b1f0a8d4ae56eafca188796936a6e3723 (diff) |
USD: add USD importer
This is an initial implementation of a USD importer.
This work is comprised of Tangent Animation's open source USD importer,
combined with features @makowalski had implemented.
The design is very similar to the approach taken in the Alembic
importer. The core functionality resides in a collection of "reader"
classes, each of which is responsible for converting an instance of a
USD prim to the corresponding Blender Object representation.
The flow of control for the conversion can be followed in the
`import_startjob()` and `import_endjob()` functions in `usd_capi.cc`.
The `USDStageReader` class is responsible for traversing the USD stage
and instantiating the appropriate readers.
Reviewed By: sybren, HooglyBoogly
Differential Revision: https://developer.blender.org/D10700
Diffstat (limited to 'source/blender/io/usd/intern/usd_reader_material.h')
-rw-r--r-- | source/blender/io/usd/intern/usd_reader_material.h | 131 |
1 files changed, 131 insertions, 0 deletions
diff --git a/source/blender/io/usd/intern/usd_reader_material.h b/source/blender/io/usd/intern/usd_reader_material.h new file mode 100644 index 00000000000..3e8fc675931 --- /dev/null +++ b/source/blender/io/usd/intern/usd_reader_material.h @@ -0,0 +1,131 @@ +/* + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version 2 + * of the License, or (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software Foundation, + * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. + * + * The Original Code is Copyright (C) 2021 NVIDIA Corporation. + * All rights reserved. + */ +#pragma once + +#include "usd.h" + +#include <pxr/usd/usdShade/material.h> + +struct Main; +struct Material; +struct bNode; +struct bNodeTree; + +namespace blender::io::usd { + +/* Helper struct used when arranging nodes in columns, keeping track the + * occupancy information for a given column. I.e., for column n, + * column_offsets[n] is the y-offset (from top to bottom) of the occupied + * region in that column. */ +struct NodePlacementContext { + float origx; + float origy; + std::vector<float> column_offsets; + const float horizontal_step; + const float vertical_step; + + NodePlacementContext(float in_origx, + float in_origy, + float in_horizontal_step = 300.0f, + float in_vertical_step = 300.0f) + : origx(in_origx), + origy(in_origy), + column_offsets(64, 0.0f), + horizontal_step(in_horizontal_step), + vertical_step(in_vertical_step) + { + } +}; + +/* Converts USD materials to Blender representation. */ + +/* By default, the USDMaterialReader creates a Blender material with + * the same name as the USD material. If the USD material has a + * UsdPreviewSurface source, the Blender material's viewport display + * color, roughness and metallic properties are set to the corresponding + * UsdPreoviewSurface inputs. + * + * If the Import USD Preview option is enabled, the current implementation + * converts UsdPreviewSurface to Blender nodes as follows: + * + * UsdPreviewSurface -> Pricipled BSDF + * UsdUVTexture -> Texture Image + Normal Map + * UsdPrimvarReader_float2 -> UV Map + * + * Limitations: arbitrary primvar readers or UsdTransform2d not yet + * supported. For UsdUVTexture, only the file, st and sourceColorSpace + * inputs are handled. + * + * TODO(makowalski): Investigate adding support for converting additional + * shaders and inputs. Supporting certain types of inputs, such as texture + * scale and bias, will probably require creating Blender Group nodes with + * the corresponding inputs. */ + +class USDMaterialReader { + protected: + USDImportParams params_; + + Main *bmain_; + + public: + USDMaterialReader(const USDImportParams ¶ms, Main *bmain); + + Material *add_material(const pxr::UsdShadeMaterial &usd_material) const; + + protected: + void import_usd_preview(Material *mtl, const pxr::UsdShadeShader &usd_shader) const; + + void set_principled_node_inputs(bNode *principled_node, + bNodeTree *ntree, + const pxr::UsdShadeShader &usd_shader) const; + + void set_node_input(const pxr::UsdShadeInput &usd_input, + bNode *dest_node, + const char *dest_socket_name, + bNodeTree *ntree, + int column, + NodePlacementContext *r_ctx) const; + + void follow_connection(const pxr::UsdShadeInput &usd_input, + bNode *dest_node, + const char *dest_socket_name, + bNodeTree *ntree, + int column, + NodePlacementContext *r_ctx) const; + + void convert_usd_uv_texture(const pxr::UsdShadeShader &usd_shader, + const pxr::TfToken &usd_source_name, + bNode *dest_node, + const char *dest_socket_name, + bNodeTree *ntree, + int column, + NodePlacementContext *r_ctx) const; + + void load_tex_image(const pxr::UsdShadeShader &usd_shader, bNode *tex_image) const; + + void convert_usd_primvar_reader_float2(const pxr::UsdShadeShader &usd_shader, + const pxr::TfToken &usd_source_name, + bNode *dest_node, + const char *dest_socket_name, + bNodeTree *ntree, + int column, + NodePlacementContext *r_ctx) const; +}; + +} // namespace blender::io::usd |