Modifies standalone scripts to use the AppLauncher class (#312)

# Description

A few demo and tutorial doesn't use all of AppLauncher's CLI args,
supply their own --headless args, or still use SimulationApp-- this
fixes that.

## Type of change

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

## Checklist

- [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
- [ ] 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

source/standalone/demos/markers.py

@@ -29,7 +29,7 @@ AppLauncher.add_app_launcher_args(parser)
 args_cli = parser.parse_args()
 
 # launch omniverse app
-app_launcher = AppLauncher(headless=args_cli.headless)
+app_launcher = AppLauncher(args_cli)
 simulation_app = app_launcher.app
 
 """Rest everything follows."""

source/standalone/tutorials/04_sensors/run_ray_caster.py

@@ -19,17 +19,17 @@ from __future__ import annotations
 
 import argparse
 
-from omni.isaac.kit import SimulationApp
+from omni.isaac.orbit.app import AppLauncher
 
 # add argparse arguments
 parser = argparse.ArgumentParser(description="Ray Caster Test Script")
-parser.add_argument("--headless", action="store_true", default=False, help="Force display off at all times.")
+# append AppLauncher cli args
+AppLauncher.add_app_launcher_args(parser)
+# parse the arguments
 args_cli = parser.parse_args()
-
 # launch omniverse app
-config = {"headless": args_cli.headless}
-simulation_app = SimulationApp(config)
-
+app_launcher = AppLauncher(args_cli)
+simulation_app = app_launcher.app
 
 """Rest everything follows."""
 

source/standalone/tutorials/04_sensors/run_ray_caster_camera.py

@@ -23,13 +23,14 @@ from omni.isaac.orbit.app import AppLauncher
 
 # add argparse arguments
 parser = argparse.ArgumentParser(description="This script demonstrates how to use the ray-cast camera sensor.")
-parser.add_argument("--headless", action="store_true", default=False, help="Force display off at all times.")
 parser.add_argument("--num_envs", type=int, default=16, help="Number of environments to generate.")
 parser.add_argument("--save", action="store_true", default=False, help="Save the obtained data to disk.")
+# append AppLauncher cli args
+AppLauncher.add_app_launcher_args(parser)
+# parse the arguments
 args_cli = parser.parse_args()
-
 # launch omniverse app
-app_launcher = AppLauncher(headless=args_cli.headless)
+app_launcher = AppLauncher(args_cli)
 simulation_app = app_launcher.app
 
 """Rest everything follows."""