Adds Headless XR support and Centralize XR-specific Settings (#278)

Adds headless XR support to Isaac Lab and refactors the AppLauncher:
* Fixed headless XR rendering with Kit XR's OpenXR extension
* Automatically enables AR mode when running headless
* Centralized XR-specific settings from code to Kit app configuration
files
* Added new `isaaclab.python.xr.openxr.headless.kit` configuration file
* Introduced `--xr` flag in AppLauncher for explicit XR mode control
(also supports `XR=1` environment variable)
* Device resolution for XR should default to CPU unless overridden
* In a separate commit, the AppLauncher configuration resolution is
broken down to resolve the flake8 C901 complexity violation

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- [x] I have run the [`pre-commit` checks](https://pre-commit.com/) with
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- [x] I have made corresponding changes to the documentation
- [x] My changes generate no new warnings
- [x] I have added tests that prove my fix is effective or that my
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- [x] I have updated the changelog and the corresponding version in the
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apps/isaaclab.python.xr.openxr.headless.kit

+##
+# Adapted from: apps/isaaclab.python.xr.openxr.kit
+##
+
+[package]
+title = "Isaac Lab Python OpenXR Headless"
+description = "An app for running Isaac Lab with OpenXR in headless mode"
+version = "2.0.0"
+
+# That makes it browsable in UI with "experience" filter
+keywords = ["experience", "app", "usd", "headless"]
+
+[settings]
+# Note: This path was adapted to be respective to the kit-exe file location
+app.versionFile = "${exe-path}/VERSION"
+app.folder = "${exe-path}/"
+app.name = "Isaac-Sim"
+app.version = "4.5.0"
+
+[dependencies]
+"isaaclab.python.xr.openxr" = {}
+
+[settings]
+xr.profile.ar.enabled = true
+
+# Register extension folder from this repo in kit
+[settings.app.exts]
+folders = [
+    "${exe-path}/exts",  # kit extensions
+    "${exe-path}/extscore",  # kit core extensions
+    "${exe-path}/../exts",  # isaac extensions
+    "${exe-path}/../extsDeprecated",  # deprecated isaac extensions
+    "${exe-path}/../extscache",  # isaac cache extensions
+    "${exe-path}/../extsPhysics",  # isaac physics extensions
+    "${exe-path}/../isaacsim/exts",  # isaac extensions for pip
+    "${exe-path}/../isaacsim/extsDeprecated",  # deprecated isaac extensions
+    "${exe-path}/../isaacsim/extscache",  # isaac cache extensions for pip
+    "${exe-path}/../isaacsim/extsPhysics",  # isaac physics extensions for pip
+    "${app}", # needed to find other app files
+    "${app}/../source", # needed to find extensions in Isaac Lab
+]

apps/isaaclab.python.xr.openxr.kit

@@ -24,6 +24,7 @@ app.asyncRenderingLowLatency = true
 
 # For XR, set this back to default "#define OMNI_MAX_DEVICE_GROUP_DEVICE_COUNT 16"
 renderer.multiGpu.maxGpuCount = 16
+renderer.gpuEnumeration.glInterop.enabled = true # Allow Kit XR OpenXR to render headless
 
 [dependencies]
 "isaaclab.python.rendering" = {}
@@ -34,11 +35,14 @@ renderer.multiGpu.maxGpuCount = 16
 "omni.kit.xr.profile.ar" = {}
 
 [settings]
+app.xr.enabled = true
+
 # xr settings
 xr.ui.enabled = false
 xrstage.profile.ar.anchorMode = "active camera"
 xr.depth.aov = "GBufferDepth"
 defaults.xr.profile.ar.renderQuality = "off"
+rtx.rendermode = "RaytracedLighting"
 
 # Register extension folder from this repo in kit
 [settings.app.exts]

scripts/environments/teleoperation/teleop_se3_agent.py

@@ -8,15 +8,11 @@
 """Launch Isaac Sim Simulator first."""
 
 import argparse
-import os
 
 from isaaclab.app import AppLauncher
 
 # add argparse arguments
 parser = argparse.ArgumentParser(description="Keyboard teleoperation for Isaac Lab environments.")
-parser.add_argument(
-    "--disable_fabric", action="store_true", default=False, help="Disable fabric and use USD I/O operations."
-)
 parser.add_argument("--num_envs", type=int, default=1, help="Number of environments to simulate.")
 parser.add_argument("--teleop_device", type=str, default="keyboard", help="Device for interacting with environment")
 parser.add_argument("--task", type=str, default=None, help="Name of the task.")
@@ -28,7 +24,7 @@ args_cli = parser.parse_args()
 
 app_launcher_args = vars(args_cli)
 if args_cli.teleop_device.lower() == "handtracking":
-    app_launcher_args["experience"] = f'{os.environ["ISAACLAB_PATH"]}/apps/isaaclab.python.xr.openxr.kit'
+    app_launcher_args["xr"] = True
 # launch omniverse app
 app_launcher = AppLauncher(app_launcher_args)
 simulation_app = app_launcher.app
@@ -69,9 +65,7 @@ def pre_process_actions(delta_pose: torch.Tensor, gripper_command: bool) -> torc
 def main():
     """Running keyboard teleoperation with Isaac Lab manipulation environment."""
     # parse configuration
-    env_cfg = parse_env_cfg(
-        args_cli.task, device=args_cli.device, num_envs=args_cli.num_envs, use_fabric=not args_cli.disable_fabric
-    )
+    env_cfg = parse_env_cfg(args_cli.task, device=args_cli.device, num_envs=args_cli.num_envs)
     # modify configuration
     env_cfg.terminations.time_out = None
     if "Lift" in args_cli.task:

scripts/tools/record_demos.py

@@ -51,11 +51,12 @@ AppLauncher.add_app_launcher_args(parser)
 # parse the arguments
 args_cli = parser.parse_args()
 
+app_launcher_args = vars(args_cli)
 if args_cli.teleop_device.lower() == "handtracking":
-    vars(args_cli)["experience"] = f'{os.environ["ISAACLAB_PATH"]}/apps/isaaclab.python.xr.openxr.kit'
+    app_launcher_args["xr"] = True
 
 # launch the simulator
-app_launcher = AppLauncher(args_cli)
+app_launcher = AppLauncher(app_launcher_args)
 simulation_app = app_launcher.app
 
 """Rest everything follows."""

source/isaaclab/isaaclab/devices/openxr/se3_handtracking.py

@@ -11,7 +11,6 @@ from scipy.spatial.transform import Rotation, Slerp
 from typing import Final
 
 import carb
-from omni.kit.viewport.utility import get_active_viewport
 
 from ..device_base import DeviceBase
 
@@ -83,11 +82,6 @@ class Se3HandTracking(DeviceBase):
         self._alpha_rot = 0.5
         self._smoothed_delta_pos = np.zeros(3)
         self._smoothed_delta_rot = np.zeros(3)
-        # Set the XR anchormode to active camera
-        carb.settings.get_settings().set_string("/xrstage/profile/ar/anchorMode", "active camera")
-        # Select RTX - RealTime for Renderer
-        viewport_api = get_active_viewport()
-        viewport_api.set_hd_engine("rtx", "RaytracedLighting")
         self._delta_pos_scale_factor = delta_pos_scale_factor
         self._delta_rot_scale_factor = delta_rot_scale_factor
         self._frame_marker_cfg = FRAME_MARKER_CFG.copy()

source/isaaclab/isaaclab/sim/simulation_context.py

@@ -154,6 +154,8 @@ class SimulationContext(_SimulationContext):
         self._local_gui = carb_settings_iface.get("/app/window/enabled")
         # read flag for whether livestreaming GUI is enabled
         self._livestream_gui = carb_settings_iface.get("/app/livestream/enabled")
+        # read flag for whether XR GUI is enabled
+        self._xr_gui = carb_settings_iface.get("/app/xr/enabled")
 
         # read flag for whether the Isaac Lab viewport capture pipeline will be used,
         # casting None to False if the flag doesn't exist
@@ -162,7 +164,7 @@ class SimulationContext(_SimulationContext):
         # read flag for whether the default viewport should be enabled
         self._render_viewport = bool(carb_settings_iface.get("/isaaclab/render/active_viewport"))
         # flag for whether any GUI will be rendered (local, livestreamed or viewport)
-        self._has_gui = self._local_gui or self._livestream_gui
+        self._has_gui = self._local_gui or self._livestream_gui or self._xr_gui
 
         # apply render settings from render config
         if self.cfg.render.enable_translucency is not None:
@@ -193,6 +195,8 @@ class SimulationContext(_SimulationContext):
                 import omni.replicator.core as rep
 
                 rep.settings.set_render_rtx_realtime(antialiasing=self.cfg.render.antialiasing_mode)
+                # WAR: The omni.replicator.core extension sets /rtx/renderMode=RayTracedLighting with incorrect casing.
+                carb_settings_iface.set("/rtx/rendermode", "RaytracedLighting")
             except Exception:
                 pass