Address review comments

Author: nvsekkin

source/isaaclab/isaaclab/renderers/base_renderer.py

@@ -103,6 +103,26 @@ def write_output(self, render_data: Any, output_name: str, output_data: torch.Te
         """
         pass
 
+    @abstractmethod
+    def get_output_info(self, render_data: Any) -> dict[str, Any] | None:
+        """Return static metadata collected during rendering.
+
+        Renderers that produce metadata (e.g. semantic segmentation label
+        mappings) return a dictionary mapping output names to their metadata.
+        The returned dictionary is written once into :attr:`CameraData.info`
+        after the first render and is not queried again.
+
+        Renderers that do not produce metadata should return ``None``.
+
+        Args:
+            render_data: The render data object from :meth:`create_render_data`.
+
+        Returns:
+            A dictionary mapping output names to their metadata, or ``None``
+            if the renderer does not produce metadata.
+        """
+        pass
+
     @abstractmethod
     def cleanup(self, render_data: Any) -> None:
         """Release renderer resources associated with the given render data.

source/isaaclab/isaaclab/sensors/camera/camera.py

@@ -19,7 +19,7 @@
 import isaaclab.sim as sim_utils
 import isaaclab.utils.sensors as sensor_utils
 from isaaclab.app.settings_manager import get_settings_manager
-from isaaclab.renderers import Renderer
+from isaaclab.renderers import BaseRenderer, Renderer
 from isaaclab.sim.views import XformPrimView
 from isaaclab.utils import has_kit, to_camel_case
 from isaaclab.utils.math import (
@@ -157,7 +157,7 @@ def __init__(self, cfg: CameraCfg):
         # Create empty variables for storing output data
         self._data = CameraData()
         # Renderer and render data — initialized in _initialize_impl
-        self.renderer: Renderer | None = None
+        self.renderer: BaseRenderer | None = None
         self.render_data = None
 
         if not has_kit():
@@ -417,8 +417,7 @@ def _initialize_impl(self):
         self.renderer.prepare_stage(self.stage, self._num_envs)
 
         # Create a view for the sensor with Fabric enabled for fast pose queries.
-        # TODO: remove sync_usd_on_fabric_write=True once the GPU (cuda:0) Fabric sync bug in
-        # renderer.update_transforms() is fixed. Without it, poses are stale on the GPU path.
+        # TODO: remove sync_usd_on_fabric_write=True once the GPU Fabric sync bug is fixed.
         self._view = XformPrimView(
             self.cfg.prim_path, device=self._device, stage=self.stage, sync_usd_on_fabric_write=True
         )
@@ -446,6 +445,7 @@ def _initialize_impl(self):
 
         # View needs to exist before creating render data
         self.render_data = self.renderer.create_render_data(self)
+        self._renderer_info_populated = False
 
         # Create internal buffers (includes intrinsic matrix and pose init)
         self._create_buffers()
@@ -468,12 +468,13 @@ def _update_buffers_impl(self, env_mask: wp.array):
                 continue
             self.renderer.write_output(self.render_data, output_name, output_data)
 
-        # Broadcast renderer info (e.g. segmentation label mappings) to all per-camera entries
-        renderer_info = getattr(self.render_data, "renderer_info", None)
-        if renderer_info:
-            for data_type, metadata in renderer_info.items():
-                for cam_idx in range(self._view.count):
-                    self._data.info[cam_idx][data_type] = metadata
+        if not self._renderer_info_populated:
+            renderer_info = self.renderer.get_output_info(self.render_data)
+            if renderer_info:
+                for data_type, metadata in renderer_info.items():
+                    for cam_idx in range(self._view.count):
+                        self._data.info[cam_idx][data_type] = metadata
+                self._renderer_info_populated = True
 
     """
     Private Helpers

source/isaaclab/test/renderers/test_renderer_factory.py

@@ -49,6 +49,9 @@ def render(self, render_data):
         def write_output(self, render_data, output_name, output_data):
             pass
 
+        def get_output_info(self, render_data):
+            return None
+
         def cleanup(self, render_data):
             pass
 

source/isaaclab_newton/isaaclab_newton/renderers/newton_warp_renderer.py

@@ -223,6 +223,11 @@ def render(self, render_data: RenderData):
             shape_index_image=render_data.outputs.instance_segmentation_image,
         )
 
+    def get_output_info(self, render_data: RenderData) -> dict[str, Any] | None:
+        """No metadata for Newton Warp.
+        See :meth:`~isaaclab.renderers.base_renderer.BaseRenderer.get_output_info`."""
+        return None
+
     def write_output(self, render_data: RenderData, output_name: str, output_data: torch.Tensor):
         """Copy a specific output to the given buffer.
         See :meth:`~isaaclab.renderers.base_renderer.BaseRenderer.write_output`."""

source/isaaclab_ov/isaaclab_ov/renderers/ovrtx_renderer.py

@@ -387,6 +387,11 @@ def update_camera(
                 wp_transforms_view = wp.from_dlpack(attr_mapping.tensor, dtype=wp.mat44d)
                 wp.copy(wp_transforms_view, camera_transforms)
 
+    def get_output_info(self, render_data: OVRTXRenderData) -> dict[str, Any] | None:
+        """No metadata for OVRTX.
+        See :meth:`~isaaclab.renderers.base_renderer.BaseRenderer.get_output_info`."""
+        return None
+
     def write_output(
         self,
         render_data: OVRTXRenderData,

source/isaaclab_physx/isaaclab_physx/renderers/isaac_rtx_renderer.py

@@ -11,7 +11,7 @@
 import logging
 import math
 import weakref
-from dataclasses import dataclass
+from dataclasses import dataclass, field
 from typing import TYPE_CHECKING, Any
 
 import numpy as np
@@ -60,7 +60,7 @@ class IsaacRtxRenderData:
     render_product_paths: list[str]
     output_data: dict[str, torch.Tensor] | None = None
     sensor: SensorBase | None = None
-    renderer_info: dict[str, Any] | None = None
+    renderer_info: dict[str, Any] = field(default_factory=dict)
 
 
 class IsaacRtxRenderer(BaseRenderer):
@@ -252,9 +252,6 @@ def tiling_grid_shape():
 
         num_tiles_x = tiling_grid_shape()[0]
 
-        if render_data.renderer_info is None:
-            render_data.renderer_info = {}
-
         # Extract the flattened image buffer
         for data_type, annotator in render_data.annotators.items():
             # check whether returned data is a dict (used for segmentation)
@@ -329,6 +326,11 @@ def tiling_grid_shape():
                     0.0 if cfg.depth_clipping_behavior == "zero" else cfg.spawn.clipping_range[1]
                 )
 
+    def get_output_info(self, render_data: IsaacRtxRenderData) -> dict[str, Any] | None:
+        """Return segmentation label mappings collected during render().
+        See :meth:`~isaaclab.renderers.base_renderer.BaseRenderer.get_output_info`."""
+        return render_data.renderer_info
+
     def write_output(self, render_data: IsaacRtxRenderData, output_name: str, output_data: torch.Tensor):
         """No-op for Isaac RTX - all outputs written in render().
         See :meth:`~isaaclab.renderers.base_renderer.BaseRenderer.write_output`."""