Fixes rendering preset (#561)

# Description

Fixes regression in parsing render preset modes.
Updates renders with recent TOT

<!-- As a practice, it is recommended to open an issue to have
discussions on the proposed pull request.
This makes it easier for the community to keep track of what is being
developed or added, and if a given feature
is demanded by more than one party. -->

## Type of change

<!-- As you go through the list, delete the ones that are not
applicable. -->

- Bug fix (non-breaking change which fixes an issue)
- New feature (non-breaking change which adds functionality)
- Breaking change (fix or feature that would cause existing
functionality to not work as expected)
- This change requires a documentation update

## Screenshots

Please attach before and after screenshots of the change if applicable.

<!--
Example:

| Before | After |
| ------ | ----- |
| _gif/png before_ | _gif/png after_ |

To upload images to a PR -- simply drag and drop an image while in edit
mode and it should upload the image directly. You can then paste that
source into the above before/after sections.
-->

## Checklist

- [X] I have run the [`pre-commit` checks](https://pre-commit.com/) with
`./isaaclab.sh --format`
- [ ] I have made corresponding changes to the documentation
- [ ] 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
- [ ] I have added my name to the `CONTRIBUTORS.md` or my name already
exists there

<!--
As you go through the checklist above, you can mark something as done by
putting an x character in it

For example,
- [x] I have done this task
- [ ] I have not done this task
-->

---------
Signed-off-by: matthewtrepte <mtrepte@nvidia.com>
Signed-off-by: Kelly Guo <kellyg@nvidia.com>
Co-authored-by: Kelly Guo <kellyg@nvidia.com>

source/isaaclab/config/extension.toml

 [package]
 
 # Note: Semantic Versioning is used: https://semver.org/
-version = "0.42.26"
+version = "0.42.27"
 
 # Description
 title = "Isaac Lab framework for Robot Learning"

source/isaaclab/docs/CHANGELOG.rst

 Changelog
 ---------
 
+0.42.27 (2025-07-21)
+~~~~~~~~~~~~~~~~~~~~
+
+Fixed
+^^^^^
+
+* Fixed rendering preset mode regression.
+
+
 0.42.26 (2025-07-22)
 ~~~~~~~~~~~~~~~~~~~~
 
@@ -9,6 +18,7 @@ Changed
 
 * Updated teleop scripts to print to console vs omni log.
 
+
 0.42.25 (2025-07-17)
 ~~~~~~~~~~~~~~~~~~~~
 

source/isaaclab/isaaclab/app/app_launcher.py

@@ -18,11 +18,8 @@ import os
 import re
 import signal
 import sys
-import toml
 from typing import Any, Literal
 
-import flatdict
-
 with contextlib.suppress(ModuleNotFoundError):
     import isaacsim  # noqa: F401
 
@@ -865,7 +862,7 @@ class AppLauncher:
                 play_button_group._stop_button = None  # type: ignore
 
     def _set_rendering_mode_settings(self, launcher_args: dict) -> None:
-        """Set RTX rendering settings to the values from the selected preset."""
+        """Store RTX rendering mode in carb settings."""
         import carb
         from isaacsim.core.utils.carb import set_carb_setting
 
@@ -879,23 +876,12 @@ class AppLauncher:
         if rendering_mode is None:
             rendering_mode = "balanced"
 
-        # parse preset file
-        repo_path = os.path.join(carb.tokens.get_tokens_interface().resolve("${app}"), "..")
-        if self.is_isaac_sim_version_4_5():
-            repo_path = os.path.join(repo_path, "..")
-        preset_filename = os.path.join(repo_path, f"apps/rendering_modes/{rendering_mode}.kit")
-        with open(preset_filename) as file:
-            preset_dict = toml.load(file)
-        preset_dict = dict(flatdict.FlatDict(preset_dict, delimiter="."))
-
-        # set presets
-        carb_setting = carb.settings.get_settings()
-        for key, value in preset_dict.items():
-            key = "/" + key.replace(".", "/")  # convert to carb setting format
-            set_carb_setting(carb_setting, key, value)
+        # store rendering mode in carb settings
+        carb_settings = carb.settings.get_settings()
+        set_carb_setting(carb_settings, "/isaaclab/rendering/rendering_mode", rendering_mode)
 
     def _set_animation_recording_settings(self, launcher_args: dict) -> None:
-        """Set animation recording settings."""
+        """Store animation recording settings in carb settings."""
         import carb
         from isaacsim.core.utils.carb import set_carb_setting
 

source/isaaclab/isaaclab/sim/simulation_context.py

@@ -333,8 +333,12 @@ class SimulationContext(_SimulationContext):
 
         not_carb_settings = ["rendering_mode", "carb_settings", "antialiasing_mode"]
 
+        # grab rendering mode, defaulting first to the CLI arg --rendering_mode
+        rendering_mode = get_carb_setting(self.carb_settings, "/isaaclab/rendering/rendering_mode")
+        if rendering_mode is None:
+            rendering_mode = self.cfg.render.rendering_mode
+
         # set preset settings (same behavior as the CLI arg --rendering_mode)
-        rendering_mode = self.cfg.render.rendering_mode
         if rendering_mode is not None:
             # check if preset is supported
             supported_rendering_modes = ["performance", "balanced", "quality"]