# UR5 Sim2Real: Data Collection & Diffusion Policy Training

This repo contains the scripts used to collect simulation demonstrations and train Diffusion Policy (DP) checkpoints for 6 robot manipulation tasks on NVIDIA L40s cluster nodes, as part of the UR5 sim2real pipeline.

## Overview

| Task | Demos | DP Checkpoint | Notes |
|------|-------|---------------|-------|
| `battery_v1` | 50 | `1027_sim_ckpt/battery_v1/latest.ckpt` | ✅ |
| `ring_v1` | 50 | `1027_sim_ckpt/ring_v1/latest.ckpt` | ✅ |
| `package_d5_v1` | 50 | `1027_sim_ckpt/package_d5_v1/latest.ckpt` | ✅ |
| `ringpeg_dart_v1` | 100 | `1027_sim_ckpt/ringpeg_dart_v1/latest.ckpt` | ✅ |
| `blb_v1` | 47 | `1027_sim_ckpt/blb_v1/latest.ckpt` | ✅ (47 due to GPU crash) |
| `plug_v1` | 50 | `1027_sim_ckpt/plug_v1/latest.ckpt` | ✅ |
| `toaster_lever` | — | — | ❌ Skipped: USD crashes Isaac Sim 5 |
| `plug1ramp_v1` | 50 (to collect) | — | 🆕 2026-10-31, `yp_task_1031.sh` |
| `battery2_v1` | 50 (to collect) | — | 🆕 2026-10-31, `yp_task_1031.sh` |
| `eraser1_v1` | 50 (to collect) | — | 🆕 2026-10-31, `yp_task_1031.sh` |

Demo zarr + collect_meta are in `1027_sim_demo/<task>/` on HuggingFace `yqi19/dagger`.

---

## Repository Layout

```
1027_run/                   # Original run (2x parallel collection)
  tasks/
    yp_task.sh              # battery / ring / plug collect + train
    package_d5.sh           # package_d5 collect + train
    bread_lever_bowl.sh     # bread_lever_bowl collect + train
    ringpeg.sh              # ringpeg collect + train
    yp_train_only.sh        # train-only (after manual merge)
    package_d5_train.sh     # package_d5 train-only
  jobs/                     # Slurm sbatch wrappers
  merge_shards.py           # merge N shard dirs into one output dir
  upload_results.sh         # HuggingFace upload script

1028_run/                   # Speedup run (4x parallel collection + AMP training)
  tasks/
    yp_task.sh              # battery / ring / plug — 4x parallel
    yp_task_1031.sh         # plug1ramp / battery2 / eraser1 — 4x parallel (2026-10-31)
    package_d5.sh
    bread_lever_bowl.sh
    ringpeg.sh
  jobs/                     # Slurm sbatch wrappers
  merge_shards.py
```

Code lives at:
```
/lustre/fsw/portfolios/nvr/users/jtremblay/yu/1027_sim_tasks/share_v5_sim2real_20260929/code/
  ur5_lab_code/             # DP training (Hydra/PyTorch)
  ur5_import/               # sim collect utils, build_scene, pack_zarr
  sim_data/                 # symlinks to per-task data dirs
  train_runs/               # training output dirs (checkpoints)
```

---

## Environment

Two conda envs on Lustre (`/lustre/fsw/portfolios/nvr/users/jtremblay/yu/miniconda3/`):

| Env | Purpose |
|-----|---------|
| `simfoundry` | Isaac Sim 5 + OmniGibson (data collection) |
| `ur5dp` | PyTorch + Diffusion Policy (training) |

Container: `robolab-isaacsim5.sqsh` (Isaac Sim 5, CUDA 12.8).

### Key env vars for collection

```bash
OMNIGIBSON_HEADLESS=1
OMNI_KIT_ACCEPT_EULA=YES
OMNIGIBSON_RENDER_VIEWER_CAMERA=0
OMNIGIBSON_DATA_PATH=.../BEHAVIOR-1K/datasets
OMNIGIBSON_GPU_ID=<0|1|2|3>   # physical GPU index (do NOT set CUDA_VISIBLE_DEVICES)
TORCH_COMPILE_DISABLE=1
TORCHDYNAMO_DISABLE=1
```

---

## Data Collection

### Camera quality

Cameras render at **native resolution** from `ur5_import/cfg/scene_real.yaml`:
- `cam0` (RealSense D455): **1280×720**, 10 fps
- `cam1` (FLIR Blackfly): **1440×1080**, 10 fps

Videos encoded with `libx264 yuv420p` via imageio/ffmpeg. Training crops both to **224×224**.

4x parallel collection does **not** affect render quality: each process gets its own Isaac Sim instance on a dedicated physical GPU (`OMNIGIBSON_GPU_ID=0/1/2/3`). Vulkan renderer + PhysX are both pinned to the same physical GPU.

### Per-task collect scripts

All tasks follow the same pattern: N parallel Isaac Sim processes → merge shards → pack zarr → train.

```
sbatch 1028_run/jobs/battery_job.sh
sbatch 1028_run/jobs/ring_job.sh
sbatch 1028_run/jobs/plug_job.sh
sbatch 1028_run/jobs/package_d5_job.sh
sbatch 1028_run/jobs/bread_lever_bowl_job.sh
sbatch 1028_run/jobs/ringpeg_job.sh
sbatch 1028_run/jobs/plug1ramp_job.sh     # 2026-10-31 tasks, see below
sbatch 1028_run/jobs/battery2_job.sh
sbatch 1028_run/jobs/eraser1_job.sh
```

### 2026-10-31 tasks (`yp_task_1031.sh`)

Same pipeline and settings as `yp_task.sh` (4 shards on GPU 0-3, seeds 200-599, max-kept 15/15/15/20, `--dart --start-offset`, merge -> pack_zarr -> AMP training, 130 epochs). Only the collector script differs:

| `TASK=` | Script | Task | Smoke test (yu_workstation, no video) | Time per demo (with video, RTX 4090) |
|---|---|---|---|---|
| `plug1ramp` | `yp_plugrack.py --task plug1ramp` | white plug from the grey ramp -> rotate wrist 45° -> into the outlet | 12/12 | ~200 s |
| `battery2` | `yp_battery2.py` | black battery -> grey holder, then white battery -> white holder | 12/12 | ~320 s |
| `eraser1` | `yp_eraser.py` | pick the eraser, wipe two black marker lines and fine stains off the fixed whiteboard (3 lanes), put the eraser back | 12/12 | ~350 s |

Setup (once): extract `1027_sim_tasks/tasks/yu_parts_tasks_1031.tar.gz` into `$TASKS` (= `.../yu/1027_sim_tasks`). It only adds files to `yu_parts_tasks/` (the shared scripts are byte-identical to the 10-27 package) and brings the new objects in `yu_parts_tasks/object_assets/objects/` (`grey_plug_ramp_test`, `white_plug_ramp_test`, `white_board`, `blue_eraser`); `yp_task_1031.sh` links them into `yu-assets` and stops with an error if they are missing. Train-only reruns: `jobs/<task>_train_job.sh` (uses `train_only.sh`, `NAME=<task>_v1`).

The eraser1 stains are a dynamic texture on the board face material (`omni.ui.DynamicTextureProvider`); the extra npz key `ink_left` is the stain fraction left per step. Details for all three tasks: `README_1031.md` inside the package. Example episodes (seed 0, cam0 | cam1): `1027_smoke_video/1031/`.

### Shard merge

```bash
python3 merge_shards.py shard_a/ shard_b/ shard_c/ shard_d/ final_dir/ 50
```

Merges episode npz + videos, renumbers indices, writes `collect_meta.json`.

---

## Training

### Config

- Config: `train_baseline_diffusion_unet` + `task=sim_baseline`
- Policy: `DiffusionUnetBaselineAugPolicy`
- 130 epochs, `checkpoint_every=129` → saves `latest.ckpt` at end
- Cam augmentation: cam1 dropout 0.1, aug_p 0.5, erase_p 0.3, cam0 aug_p 0.3

### Speed comparison

| Setting | it/s | Batches/epoch | Time for 130 epochs |
|---------|------|---------------|---------------------|
| `1027_run`: batch=64, workers=4, FP32 | ~1.1 | 324 | ~10h |
| `1028_run`: batch=256, workers=16, AMP (FP16) | ~2.5 | 39 | **~78 min** |

**Measured speedup: 7.7× on training** (tested on battery_v1, L40s GPU).

**Speedup sources:**
1. **batch_size 64→256**: 4× fewer batches per epoch
2. **AMP mixed precision** (`+training.use_amp=True`): FP16 forward/backward via `torch.cuda.amp.GradScaler` + `autocast`, ~2× throughput on L40s tensor cores
3. **num_workers 4→16**: parallel zarr.zip cache loading

AMP is patched into `train_equi_workspace.py`. Disable with `+training.use_amp=False`.

### Collection speedup

| Setting | Total collect time (50 demos) |
|---------|-------------------------------|
| `1027_run`: 2x parallel (GPU 0+2) | ~5–8h |
| `1028_run`: 4x parallel (GPU 0/1/2/3) | **~2.5h** |

**Measured: battery_v1 50 demos in 2h 26min** (4x parallel, 15+15+15+20 shards).

~270s per demo × 50 demos / 4 GPUs = ~56 min minimum. With Isaac Sim init overhead (~3 min/proc × 4 staggered) total ~2.5h.

---

## Known Issues

### Isaac Sim GPU crash (RenderGraph Error)
After ~3–4h / ~18 demos per process, Isaac Sim hits GPU memory leak. Solution: collect in short shards (max-kept=15–20), then merge.

### toaster_lever skipped
`black_toaster_lever` USD crashes `add_reference_to_stage` at the C++ layer in Isaac Sim 5. Not fixable without USD rebuild.

### OmniGibson vision_sensor patch
`vision_sensor.py` `_remove_modality_from_backend` raises `TypeError` during multi-episode teardown. Fix: wrap `detach()` in `try/except (TypeError, AttributeError)`.

### OMNIGIBSON_GPU_ID vs CUDA_VISIBLE_DEVICES
Isaac Sim uses `OMNIGIBSON_GPU_ID` for both Vulkan rendering (`active_gpu`) and PhysX CUDA (`physics_gpu`). **Do not** combine with `CUDA_VISIBLE_DEVICES` — it causes PhysX to request an invalid device ordinal.

---

## HuggingFace Upload

Dataset: `yqi19/dagger`

```
1027_sim_demo/<task>/collect_meta.json
1027_sim_demo/<task>/replay_buffer.zarr/
1027_sim_ckpt/<task>/latest.ckpt
```

Upload script: `1027_run/upload_results.sh`

---

## Cluster

- Account: `nvr_lpr_rvp`, QOS: `normal`, Partition: `batch_long`
- Node spec: L40s × 4 GPUs per node, 56 CPUs, 48GB VRAM per GPU
- `--comment=fact_off` on all jobs
- Container mounts: `/lustre/fsw/portfolios/nvr/users/jtremblay:/lustre/fsw/portfolios/nvr/users/jtremblay`