# Copyright (c) 2022-2026, The Isaac Lab Project Developers (https://github.com/isaac-sim/IsaacLab/blob/main/CONTRIBUTORS.md). # All rights reserved. # # SPDX-License-Identifier: BSD-3-Clause """ This script demonstrates USD-authored PPISP on a Gaussian scene through the Isaac Lab camera sensor with the Newton Warp or Isaac RTX renderer. .. code-block:: bash # Run a finite smoke with the default Newton Warp renderer and save comparison images. ./isaaclab.sh -p scripts/demos/sensors/ppisp_camera.py \ --input_scene /path/to/scene.usd --renderer newton --visualizer none --max_steps 60 # Run the same saved-image workflow with Isaac RTX. ./isaaclab.sh -p scripts/demos/sensors/ppisp_camera.py \ --input_scene /path/to/scene.usd --renderer isaac_rtx --visualizer none --max_steps 60 """ """Launch Isaac Sim Simulator first.""" import argparse import os from typing import Any from isaaclab.app import AppLauncher from isaaclab.utils.assets import ISAAC_NUCLEUS_DIR # add argparse arguments DEFAULT_INPUT_SCENE = f"{ISAAC_NUCLEUS_DIR}/Samples/Scene_ParticleField/valiant_auto.usdz" parser = argparse.ArgumentParser(description="Example of a USD-authored PPISP effect on camera RGB output.") parser.add_argument( "--input_scene", type=str, default=DEFAULT_INPUT_SCENE, help="USD or USDZ scene containing the Gaussian PPISP setup.", ) parser.add_argument( "--camera_prim_path", type=str, default=None, help="Optional camera prim path override. Omit to auto-select the first PPISP-bound camera.", ) parser.add_argument( "--camera_time_code", type=float, default=0.0, help="USD time code used to bake the selected camera pose into duplicated env cameras for Newton.", ) parser.add_argument( "--num_envs", type=int, default=1, help="Number of duplicated input-scene envs to render in the tiled camera batch.", ) parser.add_argument("--env_spacing", type=float, default=20.0, help="Spacing between duplicated input-scene envs.") parser.add_argument("--image_width", type=int, default=320, help="Output image width.") parser.add_argument( "--image_height", type=int, default=None, help="Output image height. Defaults to preserving the selected USD RenderProduct aspect ratio.", ) parser.add_argument("--disable_fabric", action="store_true", help="Disable Fabric API and use USD instead.") parser.add_argument( "--renderer", type=str, choices=["newton", "isaac_rtx"], default="newton", help="Camera renderer backend to use. Newton Warp is the default for this PPISP smoke.", ) parser.add_argument( "--warmup_steps", type=int, default=None, help="Simulation/render steps to run before saving images. Defaults to 32 for Isaac RTX and 0 for Newton.", ) parser.add_argument("--max_steps", type=int, default=120, help="Maximum simulation steps before exiting.") parser.add_argument("--save_interval", type=int, default=20, help="Interval, in steps, for saving comparison images.") parser.add_argument( "--ppisp_responsivity", type=float, default=None, help="Override the USD-authored PPISP responsivity. If omitted, the scene-authored value is used.", ) parser.add_argument( "--output_dir", type=str, default=None, help="Directory to write comparison images. Defaults to scripts/demos/sensors/output/ppisp_camera.", ) # append AppLauncher cli args AppLauncher.add_app_launcher_args(parser) # enable cameras by default; the QA workflow validates saved camera outputs and does not require a visualizer. parser.set_defaults(enable_cameras=True) # parse the arguments args_cli = parser.parse_args() if "://" not in args_cli.input_scene: args_cli.input_scene = os.path.abspath(os.path.expanduser(args_cli.input_scene)) if not os.path.exists(args_cli.input_scene): parser.error(f"--input_scene does not exist: {args_cli.input_scene}") if args_cli.num_envs < 1: parser.error("--num_envs must be at least 1.") if args_cli.image_width < 1: parser.error("--image_width must be at least 1.") if args_cli.image_height is not None and args_cli.image_height < 1: parser.error("--image_height must be at least 1.") if args_cli.warmup_steps is None: args_cli.warmup_steps = 32 if args_cli.renderer == "isaac_rtx" else 0 if args_cli.warmup_steps < 0: parser.error("--warmup_steps must be non-negative.") if args_cli.max_steps < 1: parser.error("--max_steps must be at least 1.") if args_cli.save_interval < 1: parser.error("--save_interval must be at least 1.") # launch omniverse app app_launcher = AppLauncher(args_cli) simulation_app = app_launcher.app """Rest everything follows.""" import matplotlib.pyplot as plt import numpy as np import torch from isaaclab_ppisp.cfg import PpispCfg, ppisp_cfg_from_usd_shader from pxr import Usd, UsdGeom, UsdShade import isaaclab.sim as sim_utils from isaaclab.assets import AssetBaseCfg, RigidObjectCfg from isaaclab.scene import InteractiveScene, InteractiveSceneCfg from isaaclab.sensors import Camera, CameraCfg from isaaclab.utils.configclass import configclass @configclass class PpispCameraSceneCfg(InteractiveSceneCfg): """Minimal scene cfg that references the input USD under each env.""" env_spacing: float = 20.0 input_scene = AssetBaseCfg( prim_path="{ENV_REGEX_NS}/Scene", spawn=sim_utils.UsdFileCfg(usd_path=""), ) anchor = RigidObjectCfg( prim_path="{ENV_REGEX_NS}/Anchor", spawn=sim_utils.CuboidCfg( size=(0.01, 0.01, 0.01), rigid_props=sim_utils.RigidBodyPropertiesCfg(), mass_props=sim_utils.MassPropertiesCfg(mass=0.001), collision_props=sim_utils.CollisionPropertiesCfg(), physics_material=sim_utils.RigidBodyMaterialCfg(), visual_material=sim_utils.PreviewSurfaceCfg(diffuse_color=(0.0, 0.0, 0.0)), ), init_state=RigidObjectCfg.InitialStateCfg(pos=(0.0, 0.0, -100.0)), ) def make_renderer_cfg() -> Any: """Create the selected camera renderer cfg.""" if args_cli.renderer == "newton": from isaaclab_newton.renderers import NewtonWarpRendererCfg return NewtonWarpRendererCfg() else: from isaaclab_physx.renderers import IsaacRtxRendererCfg return IsaacRtxRendererCfg() def make_sim_cfg() -> sim_utils.SimulationCfg: """Create the simulation cfg matching the selected renderer.""" physics_cfg = None if args_cli.renderer == "newton": from isaaclab_newton.physics.mjwarp_manager_cfg import MJWarpSolverCfg from isaaclab_newton.physics.newton_manager_cfg import NewtonCfg physics_cfg = NewtonCfg(solver_cfg=MJWarpSolverCfg(), num_substeps=1) return sim_utils.SimulationCfg( dt=0.005, device=args_cli.device, physics=physics_cfg, use_fabric=not args_cli.disable_fabric, ) def find_ppisp_camera_bindings(stage: Usd.Stage) -> list[tuple[str, Usd.Prim, Usd.Prim]]: """Return camera, RenderProduct, and PPISP shader bindings from a source stage.""" bindings = [] for prim in stage.Traverse(): if prim.GetTypeName() != "RenderProduct": continue shader_prim = stage.GetPrimAtPath(prim.GetPath().AppendChild("PPISP")) if not shader_prim or not shader_prim.IsValid(): continue camera_rel = prim.GetRelationship("camera") if not camera_rel: continue for target in camera_rel.GetTargets(): camera_prim = stage.GetPrimAtPath(target) if camera_prim and camera_prim.IsValid(): bindings.append((str(target), prim, shader_prim)) return bindings def order_ppisp_bindings_by_camera( stage: Usd.Stage, ppisp_bindings: list[tuple[str, Usd.Prim, Usd.Prim]] ) -> list[tuple[str, Usd.Prim, Usd.Prim]]: """Return PPISP bindings ordered by source Camera prim traversal.""" binding_by_camera_path = {} for binding in ppisp_bindings: binding_by_camera_path.setdefault(binding[0], binding) ordered_bindings = [] seen_paths = set() for prim in stage.Traverse(): if prim.GetTypeName() != "Camera": continue camera_path = str(prim.GetPath()) binding = binding_by_camera_path.get(camera_path) if binding is not None: ordered_bindings.append(binding) seen_paths.add(camera_path) for binding in ppisp_bindings: if binding[0] not in seen_paths: ordered_bindings.append(binding) seen_paths.add(binding[0]) return ordered_bindings def format_available_ppisp_cameras(ppisp_bindings: list[tuple[str, Usd.Prim, Usd.Prim]]) -> str: """Format PPISP-bound camera paths for CLI error messages.""" return "\n ".join(dict.fromkeys(binding[0] for binding in ppisp_bindings)) def resolve_source_camera_binding(source_stage: Usd.Stage) -> tuple[str, Usd.Prim, Usd.Prim]: """Resolve the source camera and PPISP shader binding from CLI or source stage metadata.""" ppisp_bindings = order_ppisp_bindings_by_camera(source_stage, find_ppisp_camera_bindings(source_stage)) if not ppisp_bindings: raise RuntimeError("No PPISP RenderProduct bindings found in input scene.") if args_cli.camera_prim_path is not None: camera_prim_path = args_cli.camera_prim_path if not camera_prim_path.startswith("/"): camera_prim_path = f"/{camera_prim_path}" else: camera_prim_path = ppisp_bindings[0][0] print(f"[INFO] Auto-selected camera prim: {camera_prim_path}", flush=True) camera_prim = source_stage.GetPrimAtPath(camera_prim_path) if not camera_prim or not camera_prim.IsValid(): available = format_available_ppisp_cameras(ppisp_bindings) raise RuntimeError( f"Camera prim not found: {camera_prim_path}\n" "Omit --camera_prim_path to auto-select a PPISP-bound camera, or use one of:\n" f" {available}" ) if camera_prim.GetTypeName() != "Camera": available = format_available_ppisp_cameras(ppisp_bindings) raise RuntimeError( f"Prim is not a Camera: {camera_prim_path} ({camera_prim.GetTypeName()})\n" "Omit --camera_prim_path to auto-select a PPISP-bound camera, or use one of:\n" f" {available}" ) for binding in ppisp_bindings: if binding[0] == camera_prim_path: return binding available = format_available_ppisp_cameras(ppisp_bindings) raise RuntimeError( f"Selected camera has no PPISP RenderProduct binding: {camera_prim_path}\n" "Omit --camera_prim_path to auto-select a PPISP-bound camera, or use one of:\n" f" {available}" ) def source_camera_path_to_default_rel_path(source_stage: Usd.Stage, source_camera_prim_path: str) -> str: """Return the source camera path relative to the source defaultPrim.""" default_prim = source_stage.GetDefaultPrim() if not default_prim: raise RuntimeError("Input scene must have a defaultPrim so it can be referenced under each env.") default_prim_path = default_prim.GetPath().pathString default_prefix = f"{default_prim_path}/" if not source_camera_prim_path.startswith(default_prefix): raise RuntimeError( f"Camera path {source_camera_prim_path} is not under source defaultPrim {default_prim_path}." ) return source_camera_prim_path[len(default_prefix) :] def source_camera_path_to_env_regex(source_stage: Usd.Stage, source_camera_prim_path: str) -> str: """Map a source camera path to the duplicated-env camera regex.""" camera_rel_path = source_camera_path_to_default_rel_path(source_stage, source_camera_prim_path) return f"/World/envs/env_.*/Scene/{camera_rel_path}" def bake_source_camera_pose_to_envs(source_stage: Usd.Stage, source_camera_prim_path: str) -> None: """Bake the selected USD camera pose at ``camera_time_code`` into duplicated env camera prims.""" default_prim = source_stage.GetDefaultPrim() if not default_prim: raise RuntimeError("Input scene must have a defaultPrim so it can be referenced under each env.") source_camera_prim = source_stage.GetPrimAtPath(source_camera_prim_path) if not source_camera_prim or not source_camera_prim.IsValid(): raise RuntimeError(f"Camera prim not found: {source_camera_prim_path}") time_code = Usd.TimeCode(args_cli.camera_time_code) source_cache = UsdGeom.XformCache(time_code) source_default_world = source_cache.GetLocalToWorldTransform(default_prim) source_camera_world = source_cache.GetLocalToWorldTransform(source_camera_prim) source_camera_in_default = source_camera_world * source_default_world.GetInverse() stage = sim_utils.get_current_stage() target_cache = UsdGeom.XformCache(Usd.TimeCode.Default()) camera_rel_path = source_camera_path_to_default_rel_path(source_stage, source_camera_prim_path) authored_count = 0 for env_id in range(args_cli.num_envs): scene_path = f"/World/envs/env_{env_id}/Scene" target_camera_path = f"{scene_path}/{camera_rel_path}" scene_prim = stage.GetPrimAtPath(scene_path) target_camera_prim = stage.GetPrimAtPath(target_camera_path) if not scene_prim or not scene_prim.IsValid(): raise RuntimeError(f"Duplicated scene prim not found: {scene_path}") if not target_camera_prim or not target_camera_prim.IsValid(): raise RuntimeError(f"Duplicated camera prim not found: {target_camera_path}") target_scene_world = target_cache.GetLocalToWorldTransform(scene_prim) target_parent_world = target_cache.GetLocalToWorldTransform(target_camera_prim.GetParent()) target_camera_world = source_camera_in_default * target_scene_world target_camera_local = target_camera_world * target_parent_world.GetInverse() target_camera_local.Orthonormalize() xformable = UsdGeom.Xformable(target_camera_prim) xformable.ClearXformOpOrder() xform_op = xformable.AddTransformOp(UsdGeom.XformOp.PrecisionDouble, "ppispCameraPose") xform_op.Set(target_camera_local, Usd.TimeCode.Default()) xformable.SetXformOpOrder([xform_op]) authored_count += 1 print( f"[INFO] Baked camera pose at USD time {args_cli.camera_time_code:g} into {authored_count} env camera(s).", flush=True, ) def get_render_product_resolution(render_product_prim: Usd.Prim) -> tuple[int, int] | None: """Return ``(width, height)`` from a RenderProduct ``resolution`` attribute.""" resolution_attr = render_product_prim.GetAttribute("resolution") if not resolution_attr: return None resolution = resolution_attr.Get() if resolution is None or len(resolution) != 2: return None return int(resolution[0]), int(resolution[1]) def resolve_image_shape(render_product_prim: Usd.Prim) -> tuple[int, int]: """Resolve demo output ``(width, height)`` preserving source aspect when height is omitted.""" width = args_cli.image_width height = args_cli.image_height if height is not None: return width, height source_resolution = get_render_product_resolution(render_product_prim) if source_resolution is None: return width, width source_width, source_height = source_resolution height = max(1, round(width * source_height / source_width)) return width, height def make_ppisp_cfg(shader_prim: Usd.Prim, num_ppisp_bindings: int) -> PpispCfg: """Parse the selected source PPISP shader into an explicit cfg for duplicated envs.""" ppisp_cfg = ppisp_cfg_from_usd_shader(UsdShade.Shader(shader_prim)) # The duplicated stage does not carry the source /Render scope; keep the # parsed inputs as explicit values instead of resolving this source path later. ppisp_cfg.shader_prim_path = None if args_cli.ppisp_responsivity is None: print(f"[INFO] Using USD-authored PPISP values from {num_ppisp_bindings} PPISP shader(s).", flush=True) else: ppisp_cfg.inputs["responsivity"] = float(args_cli.ppisp_responsivity) print( f"[INFO] Applied PPISP responsivity={args_cli.ppisp_responsivity:g} to duplicated env PPISP cfg.", flush=True, ) return ppisp_cfg def create_duplicated_env_scene() -> InteractiveScene: """Create a production-style duplicated-env scene for tiled camera rendering.""" scene_cfg = PpispCameraSceneCfg(num_envs=args_cli.num_envs, env_spacing=args_cli.env_spacing) scene_cfg.input_scene.spawn = sim_utils.UsdFileCfg(usd_path=args_cli.input_scene) scene = InteractiveScene(scene_cfg) print(f"[INFO] Referenced input scene into {args_cli.num_envs} env(s).", flush=True) return scene def make_camera(camera_prim_path: str, *, ppisp_cfg: PpispCfg | None, width: int, height: int) -> Camera: """Create a baseline or PPISP camera sensor for the duplicated-env camera batch.""" return Camera( CameraCfg( prim_path=camera_prim_path, update_period=0.0, height=height, width=width, data_types=["rgb"], spawn=None, isp_cfg=ppisp_cfg, renderer_cfg=make_renderer_cfg(), ) ) def save_images_grid( images: list[torch.Tensor], nrow: int = 1, subtitles: list[str] | None = None, title: str | None = None, filename: str | None = None, ) -> None: """Save images in a grid with optional subtitles and title.""" n_images = len(images) ncol = int(np.ceil(n_images / nrow)) fig, axes = plt.subplots(nrow, ncol, figsize=(ncol * 3, nrow * 3)) if isinstance(axes, np.ndarray): axes = axes.flatten() else: axes = np.array([axes]) for idx, (img, ax) in enumerate(zip(images, axes)): ax.imshow(img.detach().cpu().clamp(0.0, 1.0).numpy()) ax.axis("off") if subtitles: ax.set_title(subtitles[idx]) for ax in axes[n_images:]: fig.delaxes(ax) if title: plt.suptitle(title) plt.tight_layout() if filename: os.makedirs(os.path.dirname(filename), exist_ok=True) plt.savefig(filename) plt.close() def make_tiled_image(images: torch.Tensor) -> torch.Tensor: """Stack a camera batch vertically into one image.""" return torch.cat([image for image in images], dim=0) def save_tensor_image(image: torch.Tensor, filename: str) -> None: """Save a tensor image in [0, 1] without axes, titles, or layout scaling.""" os.makedirs(os.path.dirname(filename), exist_ok=True) plt.imsave(filename, image.detach().cpu().clamp(0.0, 1.0).numpy()) def corner_center_ratio(rgb: torch.Tensor) -> float: """Return the average corner brightness divided by center brightness for one RGB image.""" h, w = rgb.shape[:2] patch = max(4, min(h, w) // 8) cy, cx = h // 2 - patch // 2, w // 2 - patch // 2 center = rgb[cy : cy + patch, cx : cx + patch, :3].float().mean() corners = torch.stack( [ rgb[:patch, :patch, :3].float().mean(), rgb[:patch, -patch:, :3].float().mean(), rgb[-patch:, :patch, :3].float().mean(), rgb[-patch:, -patch:, :3].float().mean(), ] ).mean() return (corners / center.clamp_min(1.0)).item() def run_simulator(sim: sim_utils.SimulationContext, baseline_camera: Camera, ppisp_camera: Camera) -> None: """Run the simulator and periodically save baseline-vs-PPISP images.""" sim_dt = sim.get_physics_dt() output_dir = args_cli.output_dir if output_dir is None: output_dir = os.path.join(os.path.dirname(os.path.realpath(__file__)), "output", "ppisp_camera") os.makedirs(output_dir, exist_ok=True) if args_cli.warmup_steps > 0: print(f"[INFO] Running {args_cli.warmup_steps} warmup step(s) before saving images.", flush=True) for _ in range(args_cli.warmup_steps): sim.step() baseline_camera.update(sim_dt) ppisp_camera.update(sim_dt) count = 0 reported_shape = False while simulation_app.is_running(): sim.step() baseline_camera.update(sim_dt) ppisp_camera.update(sim_dt) count += 1 if count % args_cli.save_interval == 0: baseline = baseline_camera.data.output["rgb"][..., :3] ppisp = ppisp_camera.data.output["rgb"][..., :3] diff = (ppisp.float() - baseline.float()).abs() / 255.0 if not reported_shape: print(f"[INFO] camera batch rgb shape={tuple(ppisp.shape)}", flush=True) reported_shape = True mean_abs_delta = diff.mean().item() * 255.0 ratios = [corner_center_ratio(ppisp[i]) for i in range(ppisp.shape[0])] ratio = sum(ratios) / len(ratios) per_env_delta = diff.mean(dim=(1, 2, 3)) * 255.0 per_env_ppisp_mean = ppisp.float().mean(dim=(1, 2, 3)) print( f"[INFO] step={count} mean_abs_delta={mean_abs_delta:.2f} mean_ppisp_corner_center_ratio={ratio:.3f}", flush=True, ) print( "[INFO] per-env mean_abs_delta=" + ", ".join(f"{value:.2f}" for value in per_env_delta.detach().cpu().tolist()), flush=True, ) print( "[INFO] per-env ppisp_mean=" + ", ".join(f"{value:.2f}" for value in per_env_ppisp_mean.detach().cpu().tolist()), flush=True, ) images = [] subtitles = [] for env_id in range(ppisp.shape[0]): images.extend( [ baseline[env_id].float() / 255.0, ppisp[env_id].float() / 255.0, diff[env_id], ] ) subtitles.extend([f"env {env_id} baseline", f"env {env_id} PPISP", f"env {env_id} diff"]) save_images_grid( images, nrow=ppisp.shape[0], subtitles=subtitles, title="USD-authored PPISP on duplicated Gaussian scene envs", filename=os.path.join(output_dir, f"ppisp_camera_{count:04d}.png"), ) save_tensor_image( make_tiled_image(baseline.float() / 255.0), os.path.join(output_dir, f"ppisp_camera_{count:04d}_baseline_tiled.png"), ) save_tensor_image( make_tiled_image(ppisp.float() / 255.0), os.path.join(output_dir, f"ppisp_camera_{count:04d}_ppisp_tiled.png"), ) save_tensor_image( make_tiled_image(diff), os.path.join(output_dir, f"ppisp_camera_{count:04d}_diff_tiled.png"), ) if args_cli.max_steps is not None and count >= args_cli.max_steps: break def main() -> None: """Main function.""" source_stage = Usd.Stage.Open(args_cli.input_scene) if source_stage is None: raise RuntimeError(f"Failed to open input scene: {args_cli.input_scene}") source_camera_prim_path, render_product_prim, shader_prim = resolve_source_camera_binding(source_stage) ppisp_cfg = make_ppisp_cfg(shader_prim, len(find_ppisp_camera_bindings(source_stage))) camera_prim_path = source_camera_path_to_env_regex(source_stage, source_camera_prim_path) width, height = resolve_image_shape(render_product_prim) sim_utils.create_new_stage() sim_cfg = make_sim_cfg() sim = sim_utils.SimulationContext(sim_cfg) sim.set_camera_view(eye=[2.5, 2.5, 2.5], target=[0.0, 0.0, 0.0]) scene = create_duplicated_env_scene() if args_cli.renderer == "newton": bake_source_camera_pose_to_envs(source_stage, source_camera_prim_path) baseline_camera = make_camera(camera_prim_path, ppisp_cfg=None, width=width, height=height) ppisp_camera = make_camera(camera_prim_path, ppisp_cfg=ppisp_cfg, width=width, height=height) print(f"[INFO] Duplicated-env camera regex: {camera_prim_path}", flush=True) print(f"[INFO] Rendering {width}x{height} from source camera {source_camera_prim_path}.", flush=True) sim.reset() print("[INFO]: Setup complete. Saving comparison images during simulation.", flush=True) run_simulator(sim, baseline_camera, ppisp_camera) del scene if __name__ == "__main__": main() simulation_app.close()