Adds in frame transformer and demo script (#183)

# Description
Adds in a new `Sensor` that performs frame transforms.

No tests as part of this initial PR as this feature is needed by
developers. Tests will be added in with the improvements:
isaac-orbit/IsaacLab#202.

Fixes #133 

## Type of change
- New feature (non-breaking change which adds functionality)

## Screenshots

![image](https://github.com/isaac-orbit/orbit/assets/142246516/d4e2ebde-377f-4e22-9c14-8ec19b7b7498)

## Checklist

- [x] I have run the [`pre-commit` checks](https://pre-commit.com/) with
`./orbit.sh --format`
- [x] 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 updated the changelog and the corresponding version in the
extension's `config/extension.toml` file

---------

Signed-off-by: jsmith-bdai <142246516+jsmith-bdai@users.noreply.github.com>

source/extensions/omni.isaac.orbit/config/extension.toml

@@ -1,7 +1,7 @@
 [package]
 
 # Note: Semantic Versioning is used: https://semver.org/
-version = "0.9.25"
+version = "0.9.26"
 
 # Description
 title = "ORBIT framework for Robot Learning"

source/extensions/omni.isaac.orbit/docs/CHANGELOG.rst

@@ -1,6 +1,16 @@
 Changelog
 ---------
 
+0.9.26 (2023-10-31)
+~~~~~~~~~~~~~~~~~~~
+
+Added
+^^^^^
+
+* Added the sensor implementation for :class:`omni.isaac.orbit.sensors.FrameTransformer` class. Currently,
+  it handles obtaining the transformation between two frames in the same articulation.
+
+
 0.9.25 (2023-10-27)
 ~~~~~~~~~~~~~~~~~~~
 

source/extensions/omni.isaac.orbit/omni/isaac/orbit/scene/interactive_scene.py

@@ -19,7 +19,7 @@
 from pxr import PhysxSchema
 
 from omni.isaac.orbit.assets import Articulation, ArticulationCfg, AssetBaseCfg, RigidObject, RigidObjectCfg
-from omni.isaac.orbit.sensors import SensorBase, SensorBaseCfg
+from omni.isaac.orbit.sensors import FrameTransformerCfg, SensorBase, SensorBaseCfg
 from omni.isaac.orbit.terrains import TerrainImporter, TerrainImporterCfg
 
 from .interactive_scene_cfg import InteractiveSceneCfg
@@ -342,6 +342,14 @@ def _add_entities_from_cfg(self):
             elif isinstance(asset_cfg, RigidObjectCfg):
                 self.rigid_objects[asset_name] = asset_cfg.class_type(asset_cfg)
             elif isinstance(asset_cfg, SensorBaseCfg):
+                # Update target frame path(s)' regex name space for FrameTransformer
+                if isinstance(asset_cfg, FrameTransformerCfg):
+                    updated_target_frames = []
+                    for target_frame in asset_cfg.target_frames:
+                        target_frame.prim_path = target_frame.prim_path.format(ENV_REGEX_NS=self.env_regex_ns)
+                        updated_target_frames.append(target_frame)
+                    asset_cfg.target_frames = updated_target_frames
+
                 self.sensors[asset_name] = asset_cfg.class_type(asset_cfg)
             elif isinstance(asset_cfg, AssetBaseCfg):
                 # manually spawn asset

source/extensions/omni.isaac.orbit/omni/isaac/orbit/sensors/__init__.py

@@ -5,16 +5,29 @@
 
 
 """
-This subpackage contains the sensor classes that are compatible with the Isaac Sim. We include both
+This subpackage contains the sensor classes that are compatible with Isaac Sim. We include both
 USD-based and custom sensors. The USD-based sensors are the ones that are available in Omniverse and
 require creating a USD prim for them. Custom sensors, on the other hand, are the ones that are
 implemented in Python and do not require creating a USD prim for them.
+
+A prim path (or expression) is still set for each sensor based on the following schema:
+
++-------------------+--------------------------+---------------------------------------------------------------+
+| Sensor Type       | Example Prim Path        | Pre-check                                                     |
++===================+==========================+===============================================================+
+| Camera            | /World/robot/base/camera | Leaf is available, and it will spawn a USD camera             |
+| Contact Sensor    | /World/robot/feet_*      | Leaf is available and checks if the schema exists             |
+| Ray Casters       | /World/robot/base        | Leaf exists and is a physics body (Articulation / Rigid Body) |
+| Frame Transformer | /World/robot/base        | Leaf exists and is a physics body (Articulation / Rigid Body) |
++-------------------+--------------------------+---------------------------------------------------------------+
+
 """
 
 from __future__ import annotations
 
 from .camera import *  # noqa: F401, F403
 from .contact_sensor import *  # noqa: F401, F403
+from .frame_transformer import *  # noqa: F401
 from .ray_caster import *  # noqa: F401, F403
 from .sensor_base import SensorBase  # noqa: F401
 from .sensor_base_cfg import SensorBaseCfg  # noqa: F401

source/extensions/omni.isaac.orbit/omni/isaac/orbit/sensors/frame_transformer/__init__.py

@@ -0,0 +1,16 @@
+# Copyright (c) 2022, NVIDIA CORPORATION & AFFILIATES, ETH Zurich, and University of Toronto
+# All rights reserved.
+#
+# SPDX-License-Identifier: BSD-3-Clause
+
+"""
+Frame transform sensor for calculating frame transform of articulations.
+"""
+
+from __future__ import annotations
+
+from .frame_transformer import FrameTransformer
+from .frame_transformer_cfg import FrameTransformerCfg, OffsetCfg
+from .frame_transformer_data import FrameTransformerData
+
+__all__ = ["FrameTransformer", "FrameTransformerCfg", "FrameTransformerData", "OffsetCfg"]