.usda → .urdf
USD to URDF
Convert a robot description from USD to URDF in the browser. Nothing is installed and nothing is queued: the file is read, written in the other format, and handed back with a list of anything that could not be carried across.
Convert a file
Drop your USD here
Drop the folder too if the model references meshes.
Files are read on our server and deleted after a day. Nothing is published.
Reading the USD
Writing the URDF
Look at the file first
What this conversion costs
These are the things URDF has no place for. They are reported on the converted file as well, as a comment at the top, so the file itself says what is missing from it.
- Anything that is not a rigid body with physics. A USD stage can hold cameras, lights, materials and whole environments; a URDF describes one robot, so the rest is left behind.
- Mesh geometry stays a reference. USD composes meshes by reference, and the URDF points at the same files rather than embedding them.
What is read as a robot
An Xform with mass or with shapes under it becomes a link; PhysicsRevoluteJoint, PhysicsPrismaticJoint and PhysicsFixedJoint become joints between them. Prims that are neither — a light, a camera, a ground plane — are not part of the robot and do not appear.
Collision and visual are told apart by a schema
USD has no separate collision element: a shape collides because PhysicsCollisionAPI is applied to it. Shapes carrying it become <collision>, the rest become <visual>, which is the distinction a simulator acts on later.
Degrees become radians
USD states joint limits in degrees and URDF in radians, so every limit is converted. A file that came from Isaac with a ±180° hinge arrives with ±3.14159.
The two formats
- USD .usda
- NVIDIA's scene format, where a robot is ordinary geometry with UsdPhysics applied on top — what Isaac Sim opens.
- URDF .urdf
- the ROS description of a robot: links, joints, geometry and inertia, one rigid tree.
Converting is rarely the whole job. Once you have the URDF, the viewer shows what actually came across — collision geometry against visual, joint limits, where the mass sits — and the physics lab answers the question a file cannot: whether the robot stands up when gravity is switched on.