README.md

---
license: other
tags:
  - usd
  - usdz
  - isaac-sim
  - simready
  - 3d
  - robotics
pretty_name: SimReady Dataset Sample with Real Objects
size_categories:
  - n<1K
---

# SimReady Dataset Sample with Real Objects

100 SimReady assets for NVIDIA Isaac Sim, one self-contained `.usdz` per object. Each
asset has a physics setup and two visual levels of detail. Both the level of detail and
the collider type are USD variant sets, so you can switch them in Isaac Sim without
re-exporting.

## Contents

| | |
|---|---|
| Assets | 100 `.usdz` and `.glb` files |
| Up axis / units | Z-up, meters (`metersPerUnit = 1`), kilograms |
| Visual LODs | `0` = native mesh, `1` = 300k-triangle mesh (**default**) |
| Colliders | `sdf` (**default**) and `convexHull` |
| Physics | rigid body with mass, physics materials, collider meshes |

Inside each package, the root prim is `/Asset`:

```
/Asset
└─ bodies/<object>/
   ├─ mesh_obj       visual mesh (the selected LOD)
   ├─ colliders/     collider meshes (purpose "guide": not rendered)
   └─ grasp/         grasp vectors, if present (purpose "guide")
```

## Download

```python
from huggingface_hub import snapshot_download

path = snapshot_download(repo_id="ALLSIDES/ALLSIDES-Dataset-Sample-with-Real-Objects", repo_type="dataset")
```

## Using the assets in Isaac Sim

Drag a `.usdz` into the viewport or the Stage window, or add it as a reference from
Python. Either way, the asset appears under a prim of your choice (e.g. `/World/Object`),
and both variant sets are available on that prim.

### In the UI

Select the asset's top prim in the Stage window. In the **Property** panel, under
**Variants**, set:

- **`lod`**: `1` (300k triangles, default) or `0` (native, full resolution);
- **`collision_mode`**: `sdf` (default) or `convexHull`.

### From Python

```python
import omni.usd

stage = omni.usd.get_context().get_stage()
prim = stage.DefinePrim("/World/Object", "Xform")
prim.GetReferences().AddReference("/path/to/<asset>.usdz")

prim.GetVariantSet("lod").SetVariantSelection("0")                   # native mesh
prim.GetVariantSet("collision_mode").SetVariantSelection("convexHull")
```

The selections are stored on your stage, not in the `.usdz`. The package itself stays
unchanged and read-only.

### Level of detail (`lod`)

- **`1`** (default) is the 300k-triangle version, meant for simulation and synthetic data.
- **`0`** is the original scan-resolution mesh.

Each level is stored in its own file inside the package, and only the selected level is
composed into the scene.

### Colliders (`collision_mode`)

- **`sdf`** (default): signed-distance-field mesh collision on a precise collider mesh.
  It's accurate for non-convex shapes and is what the SimReady COL.001 check requires.
- **`convexHull`**: convex-hull colliders. They're cheaper and work with more PhysX
  features, but less accurate for concave geometry.

Only the selected kind is active; the other is deactivated. Mass and physics materials
are the same in both modes.

## Notes

- Colliders and grasp vectors use `purpose = "guide"`, so they don't show up in rendered
  images or synthetic data.
- To modify an asset, extract the `.usdz` (it's a zip archive).