Fixes Kit camera rendering when running headless

source/isaaclab/config/extension.toml

@@ -1,7 +1,7 @@
 [package]
 
 # Note: Semantic Versioning is used: https://semver.org/
-version = "4.5.20"
+version = "4.5.21"
 
 # Description
 title = "Isaac Lab framework for Robot Learning"

source/isaaclab/docs/CHANGELOG.rst

@@ -1,6 +1,16 @@
 Changelog
 ---------
 
+4.5.21 (2026-03-13)
+~~~~~~~~~~~~~~~~~~~
+
+Changed
+^^^^^^^
+
+* Allow app launcher to set visualizer type when headless is used.
+* Invalidate render update when reset is called.
+
+
 4.5.20 (2026-03-13)
 ~~~~~~~~~~~~~~~~~~~
 

source/isaaclab/isaaclab/app/app_launcher.py

@@ -698,10 +698,10 @@ def _resolve_headless_settings(self, launcher_args: dict, livestream_arg: int, l
             if self._cli_visualizer_explicit:
                 logger.warning(
                     "Both '--headless' and '--visualizer/--viz' were provided. "
-                    "Deprecated '--headless' takes precedence and disables all visualizers."
+                    "Visualizers are still enabled so viewport/camera pipeline runs correctly in headless."
                 )
-            self._cli_visualizer_disable_all = True
-            self._cli_visualizer_types = []
+            # Do not clear visualizers when --headless is used with --viz: headless only suppresses the
+            # GUI window; visualizers (e.g. Kit) can run headless and are needed for correct camera/resolution.
         # We allow headless kwarg to supersede HEADLESS envvar if headless_arg does not have the default value
         # Note: Headless is always true when livestreaming
         if headless_arg is True:

source/isaaclab/isaaclab/sim/simulation_context.py

@@ -594,6 +594,13 @@ def reset(self, soft: bool = False) -> None:
         self.physics_manager.reset(soft)
         for viz in self._visualizers:
             viz.reset(soft)
+        # Invalidate RTX render dedup so the first camera read after reset pumps a fresh frame.
+        try:
+            from isaaclab_physx.renderers.isaac_rtx_renderer_utils import invalidate_render_update
+
+            invalidate_render_update()
+        except ImportError:
+            pass
         # Start the timeline so the play button is pressed
         self.physics_manager.play()
         if not self._visualizers:

source/isaaclab_physx/config/extension.toml

@@ -1,7 +1,7 @@
 [package]
 
 # Note: Semantic Versioning is used: https://semver.org/
-version = "0.5.11"
+version = "0.5.12"
 
 # Description
 title = "PhysX simulation interfaces for IsaacLab core package"

source/isaaclab_physx/docs/CHANGELOG.rst

@@ -1,6 +1,15 @@
 Changelog
 ---------
 
+0.5.12 (2026-03-13)
+~~~~~~~~~~~~~~~~~~~
+
+Added
+^^^^^
+
+* Add function to invalidate render update so next camera read will pump the RTX renderer.
+
+
 0.5.11 (2026-03-13)
 ~~~~~~~~~~~~~~~~~~~
 

source/isaaclab_physx/isaaclab_physx/renderers/isaac_rtx_renderer_utils.py

@@ -16,6 +16,16 @@
 _last_render_update_key: tuple[int, int] = (0, -1)
 
 
+def invalidate_render_update() -> None:
+    """Invalidate the per-step render update stamp so the next camera read will pump the RTX renderer.
+
+    Call this from :meth:`SimulationContext.reset` so that the first observation after a reset
+    triggers a fresh render instead of reusing the pre-reset frame (which would appear stale).
+    """
+    global _last_render_update_key
+    _last_render_update_key = (0, -1)
+
+
 def ensure_isaac_rtx_render_update() -> None:
     """Ensure the Isaac RTX renderer has been pumped for the current physics step.