Kevin Zakka
e90b347cbf
PiperOrigin-RevId: 573343028 Change-Id: I4b258f91a11d1994659b0129de5ddb2077689f01
112 lines
3.8 KiB
Python
112 lines
3.8 KiB
Python
# Copyright 2023 DeepMind Technologies Limited
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#
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# Licensed under the Apache License, Version 2.0 (the "License");
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# you may not use this file except in compliance with the License.
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# You may obtain a copy of the License at
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#
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# http://www.apache.org/licenses/LICENSE-2.0
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#
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# Unless required by applicable law or agreed to in writing, software
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# distributed under the License is distributed on an "AS IS" BASIS,
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# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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# See the License for the specific language governing permissions and
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# limitations under the License.
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# ==============================================================================
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"""CLI for converting legacy MSH files to Wavefront OBJ files.
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Usage:
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python -m mujoco.msh2obj -i <msh_file> -o <obj_file>
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"""
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import argparse
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import dataclasses
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import io
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import pathlib
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import numpy as np
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@dataclasses.dataclass(frozen=True)
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class Msh:
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"""MuJoCo legacy binary msh file."""
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vertex_positions: np.ndarray
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vertex_normals: np.ndarray
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vertex_texcoords: np.ndarray
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face_vertex_indices: np.ndarray
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@staticmethod
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def create(file: pathlib.Path) -> "Msh":
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"""Create a Msh object from a .msh file."""
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if not file.exists():
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raise FileNotFoundError(f"{file} does not exist.")
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with open(file, "rb") as f:
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nvertex = np.fromfile(f, dtype=np.int32, count=1)[0]
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nnormal = np.fromfile(f, dtype=np.int32, count=1)[0]
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ntexcoord = np.fromfile(f, dtype=np.int32, count=1)[0]
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nface = np.fromfile(f, dtype=np.int32, count=1)[0]
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vertex_positions = np.fromfile(f, dtype=np.float32, count=3 * nvertex)
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vertex_normals = np.fromfile(f, dtype=np.float32, count=3 * nnormal)
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vertex_texcoords = np.fromfile(f, dtype=np.float32, count=2 * ntexcoord)
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face_vertex_indices = np.fromfile(f, dtype=np.int32, count=3 * nface)
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if vertex_positions.size != 3 * nvertex:
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raise ValueError(
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f"Invalid number of vertices: {vertex_positions.size} != 3*{nvertex}."
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)
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if vertex_normals.size != 3 * nnormal:
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raise ValueError(
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f"Invalid number of normals: {vertex_normals.size} != 3*{nnormal}."
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)
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if vertex_texcoords.size != 2 * ntexcoord:
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raise ValueError(
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f"Invalid number of texcoords: {vertex_texcoords.size} != "
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"2*{ntexcoord}."
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)
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if face_vertex_indices.size != 3 * nface:
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raise ValueError(
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f"Invalid number of faces: {face_vertex_indices.size} != 3*{nface}."
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)
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vertex_positions = vertex_positions.reshape(-1, 3)
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vertex_normals = vertex_normals.reshape(-1, 3)
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face_vertex_indices = face_vertex_indices.reshape(-1, 3)
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# Undo vertical flip done by MuJoCo's OBJ loader.
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vertex_texcoords = vertex_texcoords.reshape(-1, 2)
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vertex_texcoords[:, 1] = 1 - vertex_texcoords[:, 1]
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return Msh(
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vertex_positions=vertex_positions,
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vertex_normals=vertex_normals,
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vertex_texcoords=vertex_texcoords,
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face_vertex_indices=face_vertex_indices,
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)
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def msh_to_obj(msh_file: pathlib.Path) -> str:
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"""Convert a legacy .msh file to the .obj format."""
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msh = Msh.create(msh_file)
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out = io.StringIO()
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for x, y, z in msh.vertex_positions:
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out.write(f"v {x} {y} {z}\n")
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for x, y, z in msh.vertex_normals:
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out.write(f"vn {x} {y} {z}\n")
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for u, v in msh.vertex_texcoords:
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out.write(f"vt {u} {v}\n")
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for i, j, k in msh.face_vertex_indices:
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out.write(f"f {i+1}/{i+1}/{i+1} {j+1}/{j+1}/{j+1} {k+1}/{k+1}/{k+1}\n")
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return out.getvalue()
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if __name__ == "__main__":
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parser = argparse.ArgumentParser(description=__doc__)
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parser.add_argument("-i", "--input", type=str, help="Path to the msh file.")
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parser.add_argument("-o", "--output", type=str, help="Path to the obj file.")
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args = parser.parse_args()
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with open(pathlib.Path(args.output), "w") as f:
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f.write(msh_to_obj(pathlib.Path(args.input)))
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