Merge pull request #1714 from abhihjoshi:tendons

PiperOrigin-RevId: 651048034
Change-Id: If5b7cb55ff0007c3c6f932e62f068d1168778a33

python/mujoco/usd/camera.py

@@ -0,0 +1,53 @@
+# Copyright 2024 DeepMind Technologies Limited
+#
+# 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.
+# ==============================================================================
+"""Camera handling for USD exporter."""
+
+import mujoco.usd.utils as utils_component
+
+import numpy as np
+
+from pxr import Gf
+from pxr import Usd
+from pxr import UsdGeom
+
+
+class USDCamera:
+  """Class that handles the cameras in the USD scene."""
+
+  def __init__(self, stage: Usd.Stage, obj_name: str):
+    self.stage = stage
+
+    xform_path = f"/World/Camera_Xform_{obj_name}"
+    camera_path = f"{xform_path}/Camera_{obj_name}"
+    self.usd_xform = UsdGeom.Xform.Define(stage, xform_path)
+    self.usd_camera = UsdGeom.Camera.Define(stage, camera_path)
+    self.usd_prim = stage.GetPrimAtPath(camera_path)
+
+    # defining ops required by update function
+    self.transform_op = self.usd_xform.AddTransformOp()
+
+    self.usd_camera.CreateFocalLengthAttr().Set(12)
+    self.usd_camera.CreateFocusDistanceAttr().Set(400)
+
+    self.usd_camera.GetHorizontalApertureAttr().Set(12)
+
+    self.usd_camera.GetClippingRangeAttr().Set(Gf.Vec2f(1e-4, 1e6))
+
+  def update(self, cam_pos: np.ndarray, cam_mat: np.ndarray, frame: int):
+    """Updates the position and orientation of the camera in the scene."""
+    transformation_mat = utils_component.create_transform_matrix(
+        rotation_matrix=cam_mat, translation_vector=cam_pos
+    ).T
+    self.transform_op.Set(Gf.Matrix4d(transformation_mat.tolist()), frame)