Fixes building of documentation due to illegal unions (#506)

With remove of many future imports, it seems Sphinx doc generation was
sensitive to it. Hence, the docs were not building anymore. This MR
makes sure that those issues are resolved properly.

Built the docs locally and they work fine.

- Bug fix (non-breaking change which fixes an issue)

- [x] I have run the [`pre-commit` checks](https://pre-commit.com/) with
`./orbit.sh --format`
- [ ] I have made corresponding changes to the documentation
- [x] My changes generate no new warnings
- [ ] I have added tests that prove my fix is effective or that my
feature works
- [x] I have run all the tests with `./orbit.sh --test` and they pass
- [ ] I have updated the changelog and the corresponding version in the
extension's `config/extension.toml` file
- [x] I have added my name to the `CONTRIBUTORS.md` or my name already
exists there

docs/source/how-to/draw_markers.rst

@@ -17,7 +17,7 @@ This guide is accompanied by a sample script ``markers.py`` in the ``orbit/sourc
 
    .. literalinclude:: ../../../source/standalone/demos/markers.py
       :language: python
-      :emphasize-lines: 49-97, 112-113, 142-148
+      :emphasize-lines: 45-90, 106-107, 136-142
       :linenos:
 
 
@@ -43,7 +43,7 @@ configured from USD files.
 
 .. literalinclude:: ../../../source/standalone/demos/markers.py
    :language: python
-   :lines: 49-97
+   :lines: 45-90
    :dedent:
 
 
@@ -55,7 +55,7 @@ as arguments the pose of the markers and the corresponding marker prototypes to
 
 .. literalinclude:: ../../../source/standalone/demos/markers.py
    :language: python
-   :lines: 142-148
+   :lines: 136-142
    :dedent:
 
 

docs/source/how-to/write_articulation_cfg.rst

@@ -46,7 +46,7 @@ The last two parameters are optional. If not specified, they are kept at their d
 
 .. literalinclude:: ../../../source/extensions/omni.isaac.orbit_assets/omni/isaac/orbit_assets/cartpole.py
    :language: python
-   :lines: 17-33
+   :lines: 15-31
    :dedent:
 
 To import articulation from a URDF file instead of a USD file, you can replace the
@@ -74,7 +74,7 @@ Meanwhile, the joint positions and velocities are set to 0.0.
 
 .. literalinclude:: ../../../source/extensions/omni.isaac.orbit_assets/omni/isaac/orbit_assets/cartpole.py
    :language: python
-   :lines: 34-36
+   :lines: 32-34
    :dedent:
 
 Defining the actuator configuration
@@ -96,7 +96,7 @@ to combine them into a single actuator model.
 
    .. literalinclude:: ../../../source/extensions/omni.isaac.orbit_assets/omni/isaac/orbit_assets/cartpole.py
       :language: python
-      :lines: 37-47
+      :lines: 35-45
       :dedent:
 
 

docs/source/tutorials/01_assets/run_articulation.rst

@@ -23,7 +23,7 @@ directory.
 
    .. literalinclude:: ../../../../source/standalone/tutorials/01_assets/run_articulation.py
       :language: python
-      :emphasize-lines: 60-71, 93-106, 110-113, 118-119
+      :emphasize-lines: 58-69, 91-104, 108-111, 116-117
       :linenos:
 
 

docs/source/tutorials/01_assets/run_rigid_object.rst

@@ -20,7 +20,7 @@ The tutorial corresponds to the ``run_rigid_object.py`` script in the ``orbit/so
 
    .. literalinclude:: ../../../../source/standalone/tutorials/01_assets/run_rigid_object.py
       :language: python
-      :emphasize-lines: 57-76, 78-80, 100-110, 113-114, 120-121, 134-136, 141-142
+      :emphasize-lines: 55-74, 76-78, 98-108, 111-112, 118-119, 132-134, 139-140
       :linenos:
 
 

docs/source/tutorials/02_scene/create_scene.rst

@@ -40,7 +40,7 @@ This tutorial corresponds to the ``create_scene.py`` script within
 
    .. literalinclude:: ../../../../source/standalone/tutorials/02_scene/create_scene.py
       :language: python
-      :emphasize-lines: 52-65, 70-72, 93-94, 101-102, 107-108, 118-120
+      :emphasize-lines: 50-63, 68-70, 91-92, 99-100, 105-106, 116-118
       :linenos:
 
 

docs/source/tutorials/03_envs/create_base_env.rst

@@ -32,7 +32,7 @@ directory.
 
    .. literalinclude:: ../../../../source/standalone/tutorials/03_envs/create_cartpole_base_env.py
       :language: python
-      :emphasize-lines: 49-53, 56-73, 76-109, 112-131, 136-140, 145, 149, 154-155, 161-162
+      :emphasize-lines: 47-51, 54-71, 74-108, 111-130, 135-139, 144, 148, 153-154, 160-161
       :linenos:
 
 

docs/source/tutorials/03_envs/create_rl_env.rst

@@ -49,7 +49,7 @@ The script for running the environment ``run_cartpole_rl_env.py`` is present in
 
    .. literalinclude:: ../../../../source/standalone/tutorials/03_envs/run_cartpole_rl_env.py
       :language: python
-      :emphasize-lines: 43-47, 61-62
+      :emphasize-lines: 38-42, 56-57
       :linenos:
 
 

docs/source/tutorials/03_envs/register_rl_env_gym.rst

@@ -26,7 +26,7 @@ the :meth:`gymnasium.make` function.
 
    .. literalinclude:: ../../../../source/standalone/environments/random_agent.py
       :language: python
-      :lines: 40-51
+      :lines: 36-47
 
 
 The Code
@@ -39,7 +39,7 @@ The tutorial corresponds to the ``random_agent.py`` script in the ``orbit/source
 
    .. literalinclude:: ../../../../source/standalone/environments/random_agent.py
       :language: python
-      :emphasize-lines: 39-41, 46-51
+      :emphasize-lines: 36-37, 42-47
       :linenos:
 
 

docs/source/tutorials/03_envs/run_rl_training.rst

@@ -40,7 +40,7 @@ For this tutorial, we use the training script from `Stable-Baselines3`_ workflow
 
     .. literalinclude:: ../../../../source/standalone/workflows/sb3/train.py
       :language: python
-      :emphasize-lines: 58, 61, 67-69, 78, 92-96, 98-99, 102-110, 112, 117-125, 127-128, 135-138
+      :emphasize-lines: 57, 66, 68-70, 81, 90-98, 100, 105-113, 115-116, 121-126, 133-136
       :linenos:
 
 The Code Explained

docs/source/tutorials/04_sensors/add_sensors_on_robot.rst

@@ -37,7 +37,7 @@ The tutorial corresponds to the ``add_sensors_on_robot.py`` script in the
 
    .. literalinclude:: ../../../../source/standalone/tutorials/04_sensors/add_sensors_on_robot.py
       :language: python
-      :emphasize-lines: 74-97, 145-155, 169-170
+      :emphasize-lines: 72-95, 143-153, 167-168
       :linenos:
 
 

docs/source/tutorials/05_controllers/run_diff_ik.rst

@@ -25,7 +25,7 @@ The tutorial corresponds to the ``run_diff_ik.py`` script in the
 
    .. literalinclude:: ../../../../source/standalone/tutorials/05_controllers/run_diff_ik.py
       :language: python
-      :emphasize-lines: 100-102, 123-138, 157-159, 163-173
+      :emphasize-lines: 98-100, 121-136, 155-157, 161-171
       :linenos:
 
 

source/extensions/omni.isaac.orbit/omni/isaac/orbit/envs/rl_task_env.py

@@ -3,6 +3,9 @@
 #
 # SPDX-License-Identifier: BSD-3-Clause
 
+# needed to import for allowing type-hinting: np.ndarray | None
+from __future__ import annotations
+
 import gymnasium as gym
 import math
 import numpy as np

source/extensions/omni.isaac.orbit/omni/isaac/orbit/markers/visualization_markers.py

@@ -16,6 +16,9 @@ The marker prototypes can be configured with the :class:`VisualizationMarkersCfg
 .. _UsdGeom.PointInstancer: https://graphics.pixar.com/usd/dev/api/class_usd_geom_point_instancer.html
 """
 
+# needed to import for allowing type-hinting: np.ndarray | torch.Tensor | None
+from __future__ import annotations
+
 import numpy as np
 import torch
 from dataclasses import MISSING

source/extensions/omni.isaac.orbit/omni/isaac/orbit/sensors/camera/utils.py

@@ -5,6 +5,9 @@
 
 """Helper functions to project between pointcloud and depth images."""
 
+# needed to import for allowing type-hinting: torch.device | str | None
+from __future__ import annotations
+
 import math
 import numpy as np
 import torch

source/extensions/omni.isaac.orbit/omni/isaac/orbit/sensors/contact_sensor/contact_sensor_data.py

@@ -3,6 +3,9 @@
 #
 # SPDX-License-Identifier: BSD-3-Clause
 
+# needed to import for allowing type-hinting: torch.Tensor | None
+from __future__ import annotations
+
 import torch
 from dataclasses import dataclass
 

source/extensions/omni.isaac.orbit/omni/isaac/orbit/sim/schemas/schemas.py

@@ -2,6 +2,10 @@
 # All rights reserved.
 #
 # SPDX-License-Identifier: BSD-3-Clause
+
+# needed to import for allowing type-hinting: Usd.Stage | None
+from __future__ import annotations
+
 import carb
 import omni.isaac.core.utils.stage as stage_utils
 from pxr import PhysxSchema, Usd, UsdPhysics

source/extensions/omni.isaac.orbit/omni/isaac/orbit/terrains/utils.py

@@ -3,6 +3,9 @@
 #
 # SPDX-License-Identifier: BSD-3-Clause
 
+# needed to import for allowing type-hinting: np.ndarray | torch.Tensor | None
+from __future__ import annotations
+
 import numpy as np
 import torch
 import trimesh

source/extensions/omni.isaac.orbit/omni/isaac/orbit/utils/array.py

@@ -5,6 +5,9 @@
 
 """Sub-module containing utilities for working with different array backends."""
 
+# needed to import for allowing type-hinting: torch.device | str | None
+from __future__ import annotations
+
 import numpy as np
 import torch
 from typing import Union

source/extensions/omni.isaac.orbit/omni/isaac/orbit/utils/math.py

@@ -5,6 +5,9 @@
 
 """Sub-module containing utilities for various math operations."""
 
+# needed to import for allowing type-hinting: torch.Tensor | np.ndarray
+from __future__ import annotations
+
 import numpy as np
 import torch
 import torch.nn.functional

source/extensions/omni.isaac.orbit/omni/isaac/orbit/utils/warp/ops.py

@@ -5,6 +5,9 @@
 
 """Wrapping around warp kernels for compatibility with torch tensors."""
 
+# needed to import for allowing type-hinting: torch.Tensor | None
+from __future__ import annotations
+
 import numpy as np
 import torch
 

source/extensions/omni.isaac.orbit/test/managers/test_observation_manager.py

@@ -3,6 +3,9 @@
 #
 # SPDX-License-Identifier: BSD-3-Clause
 
+# needed to import for allowing type-hinting: torch.Tensor | None
+from __future__ import annotations
+
 """Launch Isaac Sim Simulator first."""
 
 from omni.isaac.orbit.app import AppLauncher, run_tests

source/extensions/omni.isaac.orbit_tasks/omni/isaac/orbit_tasks/utils/data_collector/robomimic_data_collector.py

@@ -5,6 +5,8 @@
 
 """Interface to collect and store data from the environment using format from `robomimic`."""
 
+# needed to import for allowing type-hinting: np.ndarray | torch.Tensor
+from __future__ import annotations
 
 import h5py
 import json

source/extensions/omni.isaac.orbit_tasks/omni/isaac/orbit_tasks/utils/wrappers/rl_games.py

@@ -31,6 +31,8 @@ for RL-Games :class:`Runner` class:
 
 """
 
+# needed to import for allowing type-hinting:gym.spaces.Box | None
+from __future__ import annotations
 
 import gym.spaces  # needed for rl-games incompatibility: https://github.com/Denys88/rl_games/issues/261
 import gymnasium

source/extensions/omni.isaac.orbit_tasks/omni/isaac/orbit_tasks/utils/wrappers/sb3.py

@@ -15,6 +15,8 @@ The following example shows how to wrap an environment for Stable-Baselines3:
 
 """
 
+# needed to import for allowing type-hinting: torch.Tensor | dict[str, torch.Tensor]
+from __future__ import annotations
 
 import gymnasium as gym
 import numpy as np

source/extensions/omni.isaac.orbit_tasks/omni/isaac/orbit_tasks/utils/wrappers/skrl.py

@@ -23,6 +23,9 @@ Or, equivalently, by directly calling the skrl library API as follows:
 
 """
 
+# needed to import for type hinting: Agent | list[Agent]
+from __future__ import annotations
+
 import copy
 import torch
 import tqdm