Add dataset card

README.md

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+---
+license: cc-by-4.0
+tags:
+  - usd
+  - openusd
+  - isaac-sim
+  - simready
+  - 3d
+  - 3d-scan
+  - robotics
+  - physics
+pretty_name: Allsides SimReady Assets
+size_categories:
+  - n<1K
+---
+
+# Allsides SimReady Assets
+
+SimReady assets of real-world objects, captured with high-quality 3D scanning by
+Allsides and converted to physics-ready OpenUSD props for NVIDIA Isaac Sim.
+
+Every asset in this dataset is a SimReady package for the
+[NVIDIA SimReady Catalog](https://github.com/NVIDIA-Omniverse/simready-central). Each
+package is validated against the SimReady Foundation profile `Robotics-Prop` and tested
+in Isaac Sim. The validation and benchmark results travel with the package.
+
+## Contents
+
+| | |
+|---|---|
+| Objects | [N] real-world objects, one package each |
+| Profile | `Robotics-Prop` [4.0.0] (SimReady Foundation) |
+| Up axis / units | Z-up, meters (`metersPerUnit = 1`), kilograms |
+| Visual LODs | `1` = 300k-triangle mesh (**default**), `0` = native scan mesh |
+| Colliders | `sdf` (**default**) and convex decomposition (CoACD) |
+| Physics | rigid body with the mass of the weighed object, friction and restitution from the material class |
+| Materials | UsdPreviewSurface PBR |
+| Semantics | Wikidata Q-code labels for the object and its materials |
+| License | CC-BY-4.0 |
+
+## Package layout
+
+Each top-level folder is one package. The folder name is the object's item ID. IDs that
+start with a digit have a leading underscore (`_0SDU0DKMY8/`), because USD names cannot
+start with a digit.
+
+```
+<ID>/
+├─ com.nvidia.simready.packaging.json        package definition (package ID, version, license)
+├─ .metadata/
+│  ├─ com.nvidia.simready.packaging.bom.json  bill of materials: every file with its SHA-256 hash
+│  ├─ <ID>_validation.json                    profile validation results
+│  └─ <ID>_benchmark.json                     Isaac Sim benchmark results
+└─ simready_usd/
+   ├─ <ID>.usd                                entry file: open or reference this one
+   ├─ .thumbs/256x256/<ID>.usd.png            thumbnail
+   ├─ payloads/                               geometry, LOD and physics layers
+   └─ textures/
+```
+
+Inside the USD, the root prim is `/Asset`:
+
+```
+/Asset
+└─ bodies/<object>/
+   ├─ mesh_obj       visual mesh (the selected LOD)
+   ├─ colliders/     collider meshes (invisible, purpose "guide")
+   └─ grasp/         grasp vectors, if present (purpose "guide")
+```
+
+The root layer carries the provenance metadata (`SimReady_Metadata`): author, license,
+category, Wikidata Q-code, extents, mass and rigid-body count.
+
+## Versions
+
+Each package is uploaded at a fixed commit of this dataset. The package ID includes the
+version: `simready.hf.ALLSIDES.simready-scanned-objects.<ID>.<version>`. The SimReady Catalog refers
+to each version by its commit-pinned URL:
+
+```
+https://huggingface.co/datasets/ALLSIDES/simready-scanned-objects/resolve/<commit>/<ID>/com.nvidia.simready.packaging.json
+```
+
+The `main` branch always holds the newest version of each package. Earlier versions stay
+available at their commits.
+
+## Download
+
+```python
+from huggingface_hub import snapshot_download
+
+path = snapshot_download(repo_id="ALLSIDES/simready-scanned-objects", repo_type="dataset")
+```
+
+To download one asset only, pass `allow_patterns`, for example `allow_patterns="A07RDPW843/*"`.
+To download a fixed version, pass the commit as `revision`.
+
+## Using the assets in Isaac Sim
+
+Drag `<ID>/simready_usd/<ID>.usd` into the viewport or the Stage window, or add it as a
+reference from Python. The asset appears under a prim of your choice (for example
+`/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` (convex decomposition).
+
+### From Python
+
+```python
+import omni.usd
+
+stage = omni.usd.get_context().get_stage()
+prim = stage.DefinePrim("/World/Object", "Xform")
+prim.GetReferences().AddReference("/path/to/<ID>/simready_usd/<ID>.usd")
+
+prim.GetVariantSet("lod").SetVariantSelection("0")                   # native mesh
+prim.GetVariantSet("collision_mode").SetVariantSelection("convexHull")
+```
+
+The selections are stored on your stage, not in the asset. The asset itself stays
+unchanged.
+
+### Level of detail (`lod`)
+
+- **`1`** (default) is the 300k-triangle version, for simulation and synthetic data.
+- **`0`** is the original scan-resolution mesh.
+
+Each level is stored in its own file inside the package. 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 is accurate for non-convex shapes.
+- **`convexHull`**: a convex decomposition of the object, made with CoACD. It is
+  cheaper and works with more PhysX features, but it is less accurate for concave
+  geometry.
+
+Only the selected kind is active. Mass and physics materials are the same in both modes.
+
+## Notes
+
+- Colliders and grasp vectors use `purpose = "guide"`, so they do not show up in
+  rendered images or synthetic data.
+- Do not edit the files of a package in place. The bill of materials records the hash of
+  every file, so an edited package no longer matches it.