---
license: apache-2.0
task_categories:
  - robotics
tags:
  - cad
  - urdf
  - mjcf
  - mujoco
  - robot-descriptions
---

# Robot descriptions from CAD assemblies

Simulator-ready robot descriptions generated from public CAD assemblies by
[Codesign](https://github.com/senthurayyappan/codesign). Each assembly ships an MJCF model that
MuJoCo compiles, its merged collision and visual meshes, a rendered preview, kinematic graph
plates, and the source assembly JSON. A URDF is included wherever serialization supports it.

## Provenance

| | |
|---|---|
| CAD source revision | `9f678a8c99891993c755a8a6a0fe7ddc1611da78` |
| Codesign revision | `f16a2b5e07dc30d82dc74975390e71ad383c37ba` |
| Codesign version | `0.4.2` |
| Shards | 1290 |
| Assemblies attempted | 128883 |

Source datasets: `fusion360-gallery` from `senthurayyappan/cad-assemblies`, `automate-onshape` from `senthurayyappan/cad-assemblies`.

## Coverage

An assembly is covered when its CAD JSON produces an MJCF kinematic model that MuJoCo compiles.

| source | compiled | eligible | coverage |
|---|---|---|---|
| fusion | 7728 | 7805 | 99.01% |
| onshape | 118559 | 118794 | 99.80% |
| **all** | **126287** | **126599** | **99.75%** |

Attempted yield, over every record including ineligible ones, is
126287/128883.

### Excluded inputs

The eligibility policy is a conservative allowlist: only objective source-record defects leave the
denominator. Framework limitations, missing joint limits, serialization failures, and simulator
compile failures all remain counted against coverage.

| reason | assemblies |
|---|---|
| `dangling_joint_reference` | 223 |
| `malformed_onshape_reference` | 1838 |
| `missing_joint_geometry` | 223 |

## Renders

Each `render.png` is an offscreen MuJoCo view of the packaged MJCF drawn with the
`link-palette-v1` style: every link receives one color from a fixed
palette, assigned deterministically from the assembly ID, so parent and child links always
differ. Colors carry no physical or joint-type meaning and the MJCF itself is uncolored.
Renders were regenerated after conversion; `render.*` and `timings.render_total_ms` in each
metadata record describe the regenerated image, while every other field describes the original
conversion.

## Layout

```
<source>/shard-NNNNN.tar          WebDataset archive of one shard's assemblies
<source>/shard-NNNNN.report.json  per-shard provenance, timings, and per-assembly records
metadata.parquet                  per-assembly index for the dataset viewer
campaign.report.json              campaign-level coverage and shard inventory
campaign.samples.csv              the same per-assembly rows as CSV
```

Each archive member is named `<assembly_id>.<suffix>`, with suffixes `json`, `metadata.json`,
`mjcf`, `urdf`, `meshes.tar`, `render.png`, `graph-raw.svg`, and `graph-robot.svg`.