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README.md

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+---
+pretty_name: UniPhys-Bench
+license: other
+license_name: uniphys-bench-dataset-terms
+license_link: LICENSE
+language:
+  - en
+tags:
+  - 3d
+  - physical-grounding
+  - articulation
+  - robotics
+  - simulation
+  - benchmark
+size_categories:
+  - 1K<n<10K
+---
+
+# UniPhys-Bench
+
+UniPhys-Bench is a human-verified benchmark for evaluating unified physical
+grounding on heterogeneous articulated 3D assets. It jointly evaluates
+articulation semantics, articulation structure, part-level intrinsic physical
+properties, and object-level scale and mass.
+
+This repository is the **primary UniPhys-Bench release**. It contains 1,473
+articulated assets provided by [Manycore Tech](https://www.manycoretech.com/)
+(群核科技), with part decompositions created by professional designers.
+
+- **Dataset:** [spatialverse/UniPhys-Bench](https://huggingface.co/datasets/spatialverse/UniPhys-Bench)
+- **Code:** [breezexian/UniPhysGen](https://github.com/breezexian/UniPhysGen)
+- **Paper:** [UniPhysGen: Unified Physical Grounding for Simulation-Ready 3D Assets](https://arxiv.org/abs/2607.13586)
+- **Training dataset:** [breezexian/UniPhys-40K](https://huggingface.co/datasets/breezexian/UniPhys-40K)
+
+## Release scope
+
+| Statistic | Value |
+| --- | ---: |
+| Articulated objects in this repository | 1,473 |
+| Entity ID range | `UPB_00000454`–`UPB_00001926` |
+| Role | Primary release |
+
+The complete benchmark used in the paper contains 1,927 objects and is hosted
+as two independent releases:
+
+| Release | Contents | Objects | Entity IDs |
+| --- | --- | ---: | --- |
+| [UniPhys-Bench](https://huggingface.co/datasets/spatialverse/UniPhys-Bench) | Manycore-provided assets | 1,473 | `UPB_00000454`–`UPB_00001926` |
+| [UniPhys-Bench Part 2](https://huggingface.co/datasets/breezexian/UniPhys-Bench-Part2) | Evaluation-only assets held out from the UniPhys-40K source distribution | 454 | `UPB_00000000`–`UPB_00000453` |
+
+The two releases use the same annotation schema and evaluation protocol. They
+are hosted separately so that each repository can state the provenance and
+terms applicable to the assets it contains. Entity IDs are globally unique
+across the two releases and should not be renumbered.
+
+Across both releases, UniPhys-Bench contains approximately 16K parts and 5.5K
+motion-relevant components. It covers diverse object categories, structural
+complexities, part granularities, modeling styles, scales, masses, materials,
+and articulation patterns.
+
+## Benchmark construction
+
+The assets in this repository were provided by Manycore Tech, and their part
+decompositions were created by professional designers. The UniPhys pipeline
+first produces articulation and physical-property annotations. Human annotators
+then inspect and correct joint type, axis, pivot, motion range,
+motion-dependent part groupings, and intrinsic physical-property plausibility
+for motion-relevant components.
+
+UniPhys-Bench Part 2 provides the complementary source-distribution split used
+by the complete benchmark. It is distributed separately and is not contained
+in this repository.
+
+## Annotation scope
+
+| Task | Inputs | Ground truth |
+| --- | --- | --- |
+| Part-level intrinsic physical grounding | object and target-part geometry | part identity, semantic descriptions, material, density, Young's modulus, hardness, Poisson's ratio, friction, graspability, and affordance |
+| Kinematic parameter grounding | object and target-part geometry | prismatic/revolute joint type, axis, pivot, and motion range |
+| Articulation structure grounding | object and target-part geometry plus candidate-part metadata | IDs of parts that move together with the target part |
+| Object-level physical grounding | complete-object geometry | object identity, category, dimensions, and mass |
+
+Part-property units follow the paper: density is in `g/cm^3`, Young's modulus
+in `GPa`, hardness in `HV`, and Poisson's ratio and friction are unitless.
+Object dimensions are `[L, W, H]` in centimeters and mass is in kilograms.
+Affordance is scored from 1 to 10, with smaller values indicating higher
+affordance.
+
+Motion labels use `B` for prismatic translation and `C` for revolute rotation.
+The broader part-level annotations additionally use `A` for contact-only and
+`D` for rigid or fixed parts.
+
+## Dataset structure
+
+Each benchmark object is stored in one `UPB_<id>` directory. For example:
+
+```text
+UPB_00000454/
+├── annotations/
+│   ├── object.json
+│   ├── part_1.json
+│   ├── part_2.json
+│   └── ...
+├── full_model/
+│   ├── model.obj
+│   ├── material.mtl
+│   └── texture files
+├── meta_data.json
+├── model.urdf
+├── parts/
+│   ├── part_1.obj
+│   ├── part_2.obj
+│   ├── material and texture files
+│   └── ...
+└── plys/
+    ├── model.ply
+    ├── 1.ply
+    ├── 2.ply
+    └── ...
+```
+
+| Path | Description |
+| --- | --- |
+| `parts/part_<id>.obj` | Decomposed part mesh, with its available MTL and texture assets. |
+| `full_model/model.obj` | Complete object OBJ produced by concatenating all released part meshes. |
+| `plys/model.ply` | Point cloud for the complete object. |
+| `plys/<id>.ply` | Part point cloud aligned with `parts/part_<id>.obj`. |
+| `annotations/object.json` | Object identity, category, real-world dimensions, and mass. |
+| `annotations/part_<id>.json` | Part semantics, intrinsic physical properties, articulation parameters, and dependency group. |
+| `meta_data.json` | Entity provenance, object summary, geometry metadata, and annotation version. |
+| `model.urdf` | Articulated assembly of all released parts using the annotated joints and motion parameters. |
+
+The same numeric part ID is used by `part_<id>.obj`, `<id>.ply`, and
+`part_<id>.json`, so geometry and annotations can be joined without an
+additional mapping file.
+
+### Simulation-ready URDF
+
+`model.urdf` assembles all parts and encodes the annotated joint types and
+motion parameters. During export, the mesh is rescaled using the annotated
+object dimensions so that the assembled asset has a real physical size. URDF
+geometry uses **meters**, while `annotations/object.json` stores dimensions in
+centimeters.
+
+> [!IMPORTANT]
+> The released URDF provides the articulated geometry and kinematic assembly,
+> but intrinsic physical properties are not written into the URDF. Density,
+> friction, mass, and other physical values should be read from the JSON
+> annotations and assigned as needed for the target simulator and experiment.
+
+### Metadata
+
+`meta_data.json` stores the dataset origin and released entity summary. A
+Manycore entity uses metadata of the following form:
+
+```json
+{
+  "id": "UPB_00000454",
+  "source": [
+    {
+      "dataset": "UniPhys-Bench",
+      "organization": "Manycore Tech Inc.",
+      "license_ref": "UniPhys-Bench"
+    }
+  ],
+  "object": {
+    "category": "Furniture/StorageFurniture",
+    "object_name": "Corner Display Cabinet with Drawer"
+  },
+  "geometry": {
+    "asset_type": "decomposed_parts",
+    "num_parts": 6,
+    "format": "obj"
+  },
+  "annotation": {
+    "version": "v1.0"
+  }
+}
+```
+
+### Part-level annotations
+
+Each `annotations/part_<id>.json` contains:
+
+- `index`: entity and part identifiers;
+- `part_level`: part name, descriptions, affordance, and graspability;
+- `basic_info`: material and intrinsic physical properties;
+- `kinematic_info`: motion type, dependency group, and joint parameters.
+
+`kinematic_info.motion_info.dependency` lists the part IDs that move together.
+For movable parts, `B` contains prismatic parameters and `C` contains revolute
+parameters; `axis`, `pos`, `range`, and `damping` describe the corresponding
+joint.
+
+### Object-level annotations
+
+`annotations/object.json` contains the object identity and global physical
+properties:
+
+```json
+{
+  "object_name": "Example Object",
+  "category": "Furniture/StorageFurniture",
+  "volume": [70.0, 68.0, 110.0],
+  "mass": 15.5
+}
+```
+
+`volume` is `[length, width, height]` in centimeters and `mass` is in
+kilograms. The values above illustrate the schema; released files contain the
+verified values for each entity.
+
+## Download and prepare
+
+Download this primary release:
+
+```bash
+hf download \
+  spatialverse/UniPhys-Bench \
+  --repo-type dataset \
+  --local-dir data/UniPhys-Bench
+```
+
+Generate model-ready point clouds:
+
+```bash
+python pre_process/generate_npzs.py \
+  --data_root data/UniPhys-Bench \
+  --output_dir data/UniPhys-Bench-processed/npzs
+```
+
+Generate one inference manifest for each evaluation task:
+
+```bash
+python pre_process/generate_jsons_for_inference.py \
+  --data_root data/UniPhys-Bench \
+  --npz_dir data/UniPhys-Bench-processed/npzs \
+  --output_dir data/UniPhys-Bench-processed/manifests
+```
+
+The command writes:
+
+```text
+manifests/
+├── intrinsic_physics_part.json
+├── intrinsic_physics_object.json
+├── kinematic_parameters.json
+└── articulation_structure.json
+```
+
+Each sample keeps its complete benchmark annotation. UniPhysGen inference
+embeds that record as `source_sample`, which the evaluation package reads as
+ground truth.
+
+To reproduce results on the complete 1,927-object benchmark, also download
+[UniPhys-Bench Part 2](https://huggingface.co/datasets/breezexian/UniPhys-Bench-Part2)
+and evaluate both releases with the same protocol. Keep the original entity IDs
+when preparing a combined data root.
+
+## Evaluation protocol
+
+The paper reports the following metrics:
+
+| Category | Metrics |
+| --- | --- |
+| Kinematic parameters | joint-type accuracy, axis angular error in degrees, pivot-to-ground-truth-axis distance, and motion-range mIoU |
+| Articulation structure | set mIoU and micro-F1 over motion-coupled part IDs |
+| Material properties | material-category accuracy, density ALDE, and friction MAE |
+| Object scale and mass | ALDE and MnRE for dimensions and mass |
+| Affordance | MAE over the 1-10 affordance score |
+
+Kinematic parameters are evaluated on ground-truth movable parts, separating
+parameter estimation from movable-part identification. Axis directions `a` and
+`-a` are treated as the same articulation axis. Pivot error is measured in a
+shared AABB-normalized object frame as point-to-ground-truth-axis distance.
+Motion ranges are canonicalized to unsigned intervals before computing IoU.
+
+Run the four evaluators on prediction JSON files or directories of per-sample
+records:
+
+```bash
+python -m eval intrinsic_physics_part PREDICTIONS \
+  --output intrinsic_physics_part_metrics.json
+python -m eval intrinsic_physics_object PREDICTIONS \
+  --output intrinsic_physics_object_metrics.json
+python -m eval kinematic_parameters PREDICTIONS \
+  --output kinematic_parameters_metrics.json
+python -m eval articulation_structure PREDICTIONS \
+  --output articulation_structure_metrics.json
+```
+
+See the [UniPhysGen README](https://github.com/breezexian/UniPhysGen#reproducing-uniphys-bench-results)
+for the complete inference workflow and checkpoint commands.
+
+## Intended use
+
+UniPhys-Bench is intended for research evaluation of unified physical
+grounding, including articulation reasoning, physical-property estimation,
+simulation-ready asset construction, embodied AI, and robotics simulation. It
+is an evaluation benchmark and should not be mixed into UniPhysGen training or
+model-selection data.
+
+## Scope and usage considerations
+
+- Human annotators verify and correct articulation annotations and assess
+  physical-property plausibility to support consistent research evaluation.
+  Physical values are reference estimates for the depicted objects.
+- The benchmark cannot cover every object category, material, mechanism, part
+  granularity, or mesh failure mode.
+- Results can depend on geometric completeness, scale correctness, texture
+  quality, and candidate part decomposition.
+
+## Licensing and provenance
+
+See [LICENSE](LICENSE) for the dataset terms that accompany this release.
+
+- **Original UniPhys annotations and metadata:** licensed under
+  [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/), to the extent
+  that the UniPhysGen Authors hold the relevant rights. Commercial use of these
+  original contributions is permitted under the license terms.
+- **Manycore-provided assets and derived representations:** meshes, textures,
+  materials, source annotations, URDF source assets, and derived geometry
+  remain subject to the applicable asset-specific release terms or
+  authorization from Manycore Tech. The annotation license does not grant
+  rights to these assets.
+
+Use the `source` field in each entity's `meta_data.json` to retain the supplied
+organization and license reference. Retain all required attribution, license,
+and modification notices when sharing the data. Citing UniPhys-Bench does not
+replace the applicable asset terms.
+
+## Citation
+
+```bibtex
+@article{li2026uniphysgen,
+  title   = {UniPhysGen: Unified Physical Grounding for Simulation-Ready 3D Assets},
+  author  = {Li, Xian and Wei, Rong and Yang, Lujie and Huang, Haolin and Fang, Junyuan and Tang, Siliang and Xiao, Jun and Tang, Rui and Li, Juncheng},
+  journal = {arXiv preprint arXiv:2607.13586},
+  year    = {2026}
+}
+```