isaac-sim-validator
GitHubIsaac Sim脚本交付前QA门禁,通过静态检查与受限执行验证导入、光照、路径及渲染配置等常见缺陷,确保仿真工作交付质量。
Trigger Scenarios
Install
npx skills add isaac-sim/IsaacSim --skill isaac-sim-validator -g -y
SKILL.md
Frontmatter
{
"name": "isaac-sim-validator",
"license": "Apache-2.0",
"metadata": {
"author": "Renato Gasoto <info@nvidia.com>"
},
"description": "Pre-delivery QA gate for Isaac Sim scripts (imports, lights, paths, frames). Level 3 executes untrusted Python unsandboxed and needs --confirm-execute. Use before handing off simulation work."
}
Isaac Sim Validator
WARNING: Level 3 executes the target script with your full user privileges. There is no container or sandbox isolation. Only use --confirm-execute on scripts you fully trust.
Purpose
Reject common delivery defects: black frames, deprecated imports, hardcoded user paths, missing lights, wrong render modes, and undersized SimulationApp configurations.
Levels 1–2 are static checks only. Level 3 runs the target Python script under timeout with the calling user's privileges. Level 3 requires an explicit --confirm-execute (or CONFIRM_EXECUTE=1) opt-in; it is not a sandbox.
Prerequisites
- Built Isaac Sim (
$ISAAC_SIM_DIRor_build/linux-x86_64/release). - NVIDIA GPU with a current driver (
nvidia-smi). - Shell env contract from
isaac-sim-orchestrator:$ISAAC_SIM_DIR,$ISAAC_LAB_DIR,$WORKSPACE_DIR.
Limitations
- Levels 1–2 cannot prove runtime correctness for every workload.
- Level 3 executes untrusted script content only after
--confirm-execute; there is no container/firejail isolation. - Thresholds target common demo/SDG failures, not all product features.
Troubleshooting
| Error / symptom | Cause | Solution |
|---|---|---|
| Extension or import not found | Wrong $ISAAC_SIM_DIR or stale build |
Point env vars at _build/linux-x86_64/release or rebuild |
| Black or empty frames | Missing lights or non-RTX render mode | Add dome/key light; confirm RTX / PathTracing settings |
| Hang on stage load or first render | MDL compile or oversized stage | Follow isolation steps in isaac-sim-troubleshooting |
Final gate before delivery. Reject outputs that fail the checks below; do not soften results.
Available Scripts
| Script | Purpose | Arguments |
|---|---|---|
scripts/validate_sim.sh |
Validate sim | positional args per script header (see script) |
Running scripts
From agent runtimes that expose skill execution helpers, invoke helpers with run_script():
run_script("scripts/validate_sim.sh", args=[])
From a built Isaac Sim tree, run the same file with ./python.sh (Linux) or python.bat (Windows) from _build/*/release, or execute shell helpers directly when they do not require the simulator.
Universal checklist (apply to every output)
| Check | Pass | On fail |
|---|---|---|
| Script path | exists, readable | reject: Script path invalid: <path> |
| File size | > 1 KB | reject: Script empty or corrupted |
isaacsim import |
uses isaacsim.*, not omni.isaac.core |
reject: Use isaacsim.* namespace; omni.isaac.core is deprecated |
SimulationApp config |
explicit width and height |
reject: SimulationApp without window args causes swapchain-capture size mismatch |
| Lights present | DomeLight (intensity >= 100) and DistantLight (>= 500) |
reject: No lighting; render will be black |
| Render mode | RayTracedLighting for iteration; PathTracing only for hero shots |
reject: PathTracing too slow for iteration; use RayTracedLighting |
| ACES tonemap | carb rtx.post.tonemap.op = 4; filmIso 200 default / 600 deep-aisle / 400 aerial |
suggest: Enable ACES (op=4) for contrast |
| Final render | >= 150 KB and mean_RGB > 30 | reject: Render is black or low-energy; check lighting |
| User paths | no /home/<user>/, hardcoded C:\path\to\..., or per-agent home paths; prefer %USERPROFILE%, env vars, or argparse |
reject: Hardcoded user path; use $ISAAC_SIM_DIR, $ISAAC_LAB_DIR, $WORKSPACE_DIR, or argparse |
| Network endpoints | no bare IPs (192.168.x.x, 10.x.x.x) or non-localhost hosts |
reject: Hardcoded endpoint; parameterize via env var or config |
| Output dir | configurable (env var, CLI, or function param) | reject: Output dir hardcoded; accept as parameter or read $OUTPUT_DIR |
| VRAM headroom | nvidia-smi headroom > 20% after settle |
warn at >90% utilization; likely leak or scale issue |
pkill -f "kit/kit" used |
flag for kill+relaunch bug | warn: Verify zero kit processes before next launch |
| Sim duration | >= 3 s of physics | reject: Sim ran < 3 s; physics has not settled |
File structure validation (USD scenes)
| Item | Valid | Invalid | Action |
|---|---|---|---|
$ISAAC_LAB_DIR/scripts/ |
read-only reference | writing outputs there | redirect to $OUTPUT_DIR or $WORKSPACE_DIR/outputs/ |
get_assets_root_path() -> s3://... |
runtime OK | baked into delivered output | cache locally; reference via configurable path |
Melting / Splat MDL-only shaders |
OK in raw form | MDL-only at export | filter out; MDL-only causes black render |
MakeInstanceable for RL |
required (make_instanceable: true) |
absent | reject |
usdPreviewSurface on surfaces |
required | absent | reject; suggest adding UsdPreviewSurface |
convex_decompose_mesh |
false (with clean_sdf_dc) |
true |
recommend false for stability |
mpu=0.01 |
OK for warehouse shell (13 m tiles) | on a robot | reject |
Render validation (frame analysis)
| Metric | Good | Bad | Action |
|---|---|---|---|
| File size | 1–4 MB | ~82 KB | 82 KB = black, reject |
| Mean RGB | 80–160 | < 20 | reject: Too dark; add lights |
| Max RGB | 200–250 | 0 | reject: No light in scene |
| Pixel variance | > 15 | < 5 | flat = missing shadows; add accents |
| Color histogram | multi-modal | single peak | overexposed or flat lighting; adjust intensity |
| Object visibility | >= 3 robots or 50+ assets | < 10 visible | suggest: Scene too sparse; add set dressing |
| Shadow consistency | consistent shadows | random black blobs | reject: Shadow artifacts; check light cone bounds |
Video validation
For any delivered MP4/GIF, extract and inspect at least start/middle/end frames. Reject or recut the presentation copy if the first frames show render warm-up, the subject is occluded, or the camera loses the task. Keep the complete source render and metrics when a shorter presentation cut is made.
RL training validation
| Issue | Action |
|---|---|
AppLauncher not first |
reject: AppLauncher must precede any isaaclab imports |
Task __init__.py non-empty |
reject: Task __init__.py must be empty; do not import configs |
omni.isaac.lab import |
reject: Use isaaclab.*; omni.isaac.lab is deprecated |
| PhysX backend (when Newton applies) | reject: Use Newton; it is the default on Kit 110 |
Missing PYTHONUNBUFFERED=1 |
warn: Set PYTHONUNBUFFERED=1 to see logs in real time |
| No GPU memory logging | suggest: Log torch.cuda.memory_allocated()/1e6 to W&B |
| Batch size exceeds VRAM | suggest: Reduce num_envs (try 2048) |
| Wrong checkpoint name | reject: Must be model_XXXX.zip, not policy.pt |
| Single seed | suggest: Run seeds 42, 123, 456 for valid comparison |
Asset & shell validation
| Input | Check | Action |
|---|---|---|
docker run command |
-v mount for /workspace/output |
reject: Output folder not mounted |
| Sub-agent spawn | workdir=$WORKSPACE_DIR |
reject: Sub-agent workdir hardcoded; use $WORKSPACE_DIR |
| Blender USD export | correct mpu, dual-shader (UsdPreviewSurface + MDL), correct export type | reject if any missing |
| Scene complexity | renders within 10 settle steps | reject: Scene too complex; simplify assets |
| Ghost artifacts | cleanup of /dev/shm/carb-* |
reject: Use workspace_cleanup.py to clear /dev/shm/carb-* |
Decision tree
graph TD
A[Received Output] --> B{Has script?}
B -->|No| C[Reject: "No script provided"]
B -->|Yes| D{File size >1KB?}
D -->|No| E[Reject: "Script empty or corrupted"]
D -->|Yes| F{Python?}
F -->|Yes| G{isaacsim.* imports?}
G -->|No| H[Reject: "Use isaacsim.* not omni.isaac.core"]
G -->|Yes| I{SimulationApp or --exec?}
I -->|Neither| J[Reject: "Must use SimulationApp with window args OR isaac-sim.sh --exec"]
I -->|SimulationApp| K{width and height set?}
K -->|No| L[Reject: "SimulationApp requires explicit width and height"]
K -->|Yes| M{Dome + Distant lights?}
M -->|No| N[Reject: "Add DomeLight and DistantLight (min intensity 100 and 500)"]
M -->|Yes| O{RayTracedLighting?}
O -->|No| P[Reject: "Use RayTracedLighting for iteration"]
O -->|Yes| Q{Render output exists?}
Q -->|No| R[Reject: "No render output"]
Q -->|Yes| S{>= 150 KB and mean_RGB > 30?}
S -->|No| T[Reject: "Render is black, too dark, or corrupted"]
S -->|Yes| U{Hardcoded user paths or bare IPs?}
U -->|Yes| V[Reject: "Replace hardcoded user paths/IPs with env vars or args"]
U -->|No| Y[VALID - deliver]
Training output
| Item | Action |
|---|---|
policy_only_XXXX.pt |
accept |
model_XXXX.zip |
accept |
log.csv or wandb URL |
accept |
results.json with episode data |
accept |
| No reward curve / metrics | reject: Log episode/reward_mean and train/value_loss |
Reply format
- Pass:
Valid: <one-line summary> - Fail:
Invalid: <list of failed checks> - Suggest (only when otherwise valid):
Could be improved: <tip>
Do not hedge ("I think", "maybe"). Do not deliver a black frame.
Input sources
isaac-sim-orchestrator,isaac-sim-rendering, other producer skills, and sub-agent outputs.- Invoked on Isaac Sim deliverables: "validate this Isaac Sim script", "check this Isaac Sim render", "review this sim output".
Automated validation
Run the checks above from the CLI with scripts/validate_sim.sh:
# Levels 1–2: static only
bash scripts/validate_sim.sh --level <1|2> <script.py> [--output-dir <dir>] [--timeout <seconds>]
# Level 3: EXECUTES the script — requires explicit opt-in
bash scripts/validate_sim.sh --level 3 --confirm-execute <script.py> [--output-dir <dir>] [--timeout <seconds>]
# or: CONFIRM_EXECUTE=1 bash scripts/validate_sim.sh --level 3 <script.py> ...
Feedback loop
- Rejections feed back into the producing skill's failure-mode catalog.
- Recurring failures become new validator rules.
- Standing rubric:
references/quality-criteria.md. Record each iteration inreferences/feedback-log.md.
Version History
- 2469084 Current 2026-09-22 15:45


