Hi all — I’m Rahul, a robotics/UAV engineer from India. Over the past months I built a set of free browser-based tools for the URDF/simulation debugging work I kept doing by hand, and I’d like to share them: https://robosimtools.com
Everything runs client-side (WASM/JS) — your files never leave your machine. No accounts, no uploads, no install.
Model checking & viewing
- URDF Validator — catches structural problems (kinematic loops, bad inertials, missing limits) with explanations, not just “parse error”
- URDF Viewer — 3D render with joint sliders and collision-geometry toggle, no ROS install needed
Format conversion
- Xacro → URDF (browser-side xacro processing)
- URDF → MJCF — output is compile-checked against real MuJoCo
- SDF → URDF — resolves the frame graph properly (transforms verified against NumPy)
- STEP → URDF — CAD assemblies to robot models via OpenCascade compiled to WASM
- DH parameters → URDF (standard and modified/Craig conventions)
Math & parameters
- Mesh Inertia Calculator — inertia tensor from STL/OBJ, plus a unit-fixer for the classic mm-scaled-mesh problem
- Rotation Converter — quaternion / all 12 Euler sequences / matrix / axis-angle, with a live 3D gizmo
- ArduPilot Param Diff — categorized diff of two .param files, every parameter annotated from ArduPilot’s official metadata
Compliance (for those shipping products into the EU)
- SBOM Generator (CycloneDX) and an EU Cyber Resilience Act readiness checker
The one rule the site runs on: every tool states how it was verified, and warns when it can’t verify something rather than guessing. The URDF→MJCF converter is compile-checked in MuJoCo; the rotation math is a port of the transformations.py algorithm behind tf.transformations, round-trip-tested across all 12 Euler sequences; the DH converter was validated against an independent transform-chain implementation over hundreds of random non-planar chains (which caught a real bug in standard-DH handling before shipping).
Honest limitations: the viewer doesn’t do OBJ or textured materials yet, the STEP converter needs meshes exported separately, and PX4 param support isn’t in the diff tool yet (no stable metadata source — suggestions welcome).
Tools chain into each other (validate → open in viewer, convert → validate), inputs autosave locally, and every text tool generates shareable links.
I built these because I kept making the same mistakes the hard way. If you find a bug or want a tool that doesn’t exist yet, there’s a bug-report form on every page — I’d genuinely like the feedback.