Provide a Blender plugin to export models as MuJoCo MJCF XML files with assets.

PiperOrigin-RevId: 605634755
Change-Id: I0d54efe1d83df08a2f51e66da6d9de23f640e58a

Author: DeepMind

dm_control/blender/fake_core/bpy.py

@@ -0,0 +1,229 @@
+# Copyright 2023 The dm_control Authors.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#    http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or  implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+# ============================================================================
+
+"""Fake Blender bpy module."""
+
+from __future__ import annotations  # postponed evaluation of annotations
+
+from typing import Any, Collection, Sequence
+
+from dm_control.blender.fake_core import mathutils
+
+# pylint: disable=invalid-name
+# pylint: disable=missing-class-docstring
+
+
+class WindowManager:
+
+  def progress_begin(self, start: int, end: int):
+    pass
+
+  def progress_update(self, steps_done: int):
+    pass
+
+  def progress_end(self):
+    pass
+
+
+class context:
+
+  @property
+  def window_manager(self) -> WindowManager:
+    return WindowManager()
+
+  @staticmethod
+  def evaluated_depsgraph_get():
+    pass
+
+
+class types:
+
+  class Constraint:
+
+    @property
+    def name(self):
+      pass
+
+    @property
+    def owner_space(self):
+      pass
+
+  class Scene:
+    pass
+
+  class Object:
+
+    @property
+    def name(self) -> str:
+      raise NotImplementedError()
+
+    @property
+    def parent(self) -> types.Object | None:
+      pass
+
+    @property
+    def parent_bone(self) -> types.Bone | None:
+      pass
+
+    @property
+    def data(self):
+      pass
+
+    @property
+    def pose(self):
+      pass
+
+    @property
+    def matrix_world(self) -> mathutils.Matrix:
+      raise NotImplementedError()
+
+    @matrix_world.setter
+    def matrix_world(self, _) -> mathutils.Matrix:
+      raise NotImplementedError()
+
+    def select_set(self, _):
+      pass
+
+    def to_mesh(self):
+      pass
+
+    def evaluated_get(self, _) -> types.Object:
+      pass
+
+    @property
+    def mode(self) -> str:
+      return 'OBJECT'
+
+    @property
+    def type(self):
+      pass
+
+    def update_from_editmode(self):
+      pass
+
+  class Bone:
+
+    @property
+    def name(self) -> str:
+      raise NotImplementedError()
+
+    @property
+    def parent(self) -> types.Bone | None:
+      pass
+
+    @property
+    def matrix_local(self) -> mathutils.Matrix:
+      raise NotImplementedError()
+
+    @property
+    def matrix(self) -> mathutils.Matrix:
+      raise NotImplementedError()
+
+  class bpy_struct:
+    pass
+
+  class Context:
+
+    @property
+    def scene(self) -> types.Scene:
+      pass
+
+  class Light:
+
+    @property
+    def type(self):
+      pass
+
+    @property
+    def use_shadow(self):
+      pass
+
+    @property
+    def color(self) -> mathutils.Color:
+      raise NotImplementedError()
+
+    @property
+    def linear_attenuation(self):
+      pass
+
+    @property
+    def quadratic_attenuation(self):
+      pass
+
+  class LimitRotationConstraint(Constraint):
+    pass
+
+  class LimitLocationConstraint(Constraint):
+    pass
+
+  class Material:
+
+    @property
+    def name(self) -> str:
+      raise NotImplementedError()
+
+    @property
+    def specular_intensity(self):
+      pass
+
+    @property
+    def metallic(self):
+      pass
+
+    @property
+    def roughness(self) -> float:
+      raise NotImplementedError()
+
+    @property
+    def diffuse_color(self) -> Sequence[float]:
+      raise NotImplementedError()
+
+  class Mesh:
+
+    @property
+    def name(self) -> str:
+      raise NotImplementedError()
+
+    def calc_loop_triangles(self):
+      pass
+
+    @property
+    def uv_layers(self) -> Any:
+      raise NotImplementedError()
+
+    @property
+    def loop_triangles(self) -> Collection[Any]:
+      raise NotImplementedError()
+
+    @property
+    def vertices(self) -> Any:
+      raise NotImplementedError()
+
+
+class ops:
+
+  class object:
+
+    @staticmethod
+    def select_all(action):
+      pass
+
+  class export_mesh:
+
+    @classmethod
+    def stl(
+        cls, filepath, use_selection, use_mesh_modifiers, axis_forward, axis_up
+    ):
+      pass

dm_control/blender/fake_core/mathutils.py

@@ -0,0 +1,123 @@
+# Copyright 2023 The dm_control Authors.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#    http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or  implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+# ============================================================================
+
+"""Fake Blender mathutils module."""
+# pylint: disable=invalid-name
+
+import numpy as np
+
+
+class Color:
+  """Fake color class."""
+
+  def __init__(self, coords):
+    self._coords = coords
+
+  @property
+  def r(self) -> float:
+    return self._coords[0]
+
+  @property
+  def g(self) -> float:
+    return self._coords[1]
+
+  @property
+  def b(self) -> float:
+    return self._coords[2]
+
+  @property
+  def a(self) -> float:
+    return self._coords[3]
+
+
+class Vector:
+  """Fake vector class."""
+
+  def __init__(self, coords):
+    self._coords = np.asarray(coords)
+
+  @property
+  def x(self) -> float:
+    return self._coords[0]
+
+  @property
+  def y(self) -> float:
+    return self._coords[1]
+
+  @property
+  def z(self) -> float:
+    return self._coords[2]
+
+  @property
+  def w(self) -> float:
+    return self._coords[3]
+
+  def __eq__(self, rhs) -> bool:
+    if not isinstance(rhs, Vector):
+      return False
+    return np.linalg.norm(self._coords - rhs._coords) < 1e-6
+
+  def __str__(self) -> str:
+    return 'Vector({:.2f}, {:.2f}, {:.2f})'.format(self.x, self.y, self.z)
+
+  def __repr__(self) -> str:
+    return 'Vector({:.2f}, {:.2f}, {:.2f})'.format(self.x, self.y, self.z)
+
+
+class Quaternion:
+  """Fake quaternion class."""
+
+  def __init__(self, coords):
+    self._coords = coords
+
+  @property
+  def x(self) -> float:
+    return self._coords[1]
+
+  @property
+  def y(self) -> float:
+    return self._coords[2]
+
+  @property
+  def z(self) -> float:
+    return self._coords[3]
+
+  @property
+  def w(self) -> float:
+    return self._coords[0]
+
+  def __matmul__(self, rhs: Vector) -> Vector:
+    return Vector((1, 0, 0))
+
+
+class Matrix:
+  """Fake matrix class."""
+
+  def __init__(self, coords):
+    self._coords = coords
+
+  @classmethod
+  def Diagonal(cls, _):
+    return cls((1,))
+
+  @property
+  def translation(self) -> Vector:
+    return Vector((0.0, 0.0, 0.0))
+
+  def to_quaternion(self) -> Quaternion:
+    return Quaternion((1.0, 0.0, 0.0, 0.0))
+
+  def to_scale(self) -> Vector:
+    return Vector((0.0, 0.0, 0.0))