URDF Studio product guide

URDF Studio is the platform workbench for robot model design and assembly. Editing URDF XML by hand is error-prone and slow; URDF Studio turns robot description files into a visual workspace where you can inspect models, adjust structure, optimize collision bodies, edit physical parameters and export model files.

Typical users include robotics algorithm engineers, ROS developers, hardware integration engineers and simulation engineers.

Save staged versions such as g1_original, g1_joint_checked_v1, g1_collision_optimized_v2 and g1_final.

URDF uses standard SI units: length in meters (m), angle in radians (rad) and mass in kilograms (kg). If the model data comes from CAD software that uses millimeters, check the scale after import.

Workspace Overview

The complete URDF Studio workspace includes the top toolbar, asset library, joint panel, structure tree, detail options, 3D view and properties panel.

The top toolbar contains common commands such as file import, measurement, AI review, source code, undo/redo, snapshot and export.

For a first pass through a model, use this order: check the asset library -> confirm the 3D model -> understand the hierarchy in the structure tree -> test with the joint panel -> check geometry and collision bodies -> check physical parameters -> export a backup.

Model Import and Integrity Checks

After importing a model, complete integrity checks before editing parameters.

Import From BotWorld

On a BotWorld resource detail page, click "Import to workspace". The page opens URDF Studio and starts loading the model.

Do not delete files that are still referenced by the model; otherwise parts or textures may be missing.

Local Import

Path: top "File" menu -> choose an import method -> select a local file -> wait for loading to complete.

If the model contains meshes, textures or other related resources, import the complete folder or ZIP package. ZIP packages should preserve the original directory structure; do not copy only the description file and omit meshes.

Three-Way Check: Asset Library, Structure Tree and 3D View

After import, confirm the model loaded correctly from the asset library, structure tree and 3D view.

Loading progress is shown during import. Wait until it finishes.

After import completes, check whether the complete robot appears in the 3D view.

If you find a problem, check files and reference paths before changing structure.

If you imported multiple files at once, find the target resource in the asset library and click "Add".

After adding the asset, it appears in the 3D view.

If multiple assets overlap, use Transform Mode to move or rotate objects.

Understand Robot Structure

Link and Joint

Joint Type Quick Reference

URDF commonly defines four joint types. Choosing the wrong joint type directly affects simulation behavior, so choose based on the real motion.

In short, fixed joints are locked; revolute and continuous joints both rotate, but only revolute joints have range limits; prismatic joints slide along an axis.

Structure Tree Hierarchy

Typical hierarchy: root -> Link (Visual + Collision) -> Joint -> Link (Visual + Collision) -> ...

Click an object name in the structure tree to highlight the corresponding object in the 3D view. Editing or deleting an upper-level object affects all child parts, so export a project backup before structural changes.

Visual Geometry vs Collision Body

Use Detail Options to display them separately and compare their positions and sizes.

Check and Modify Joints

Models from other sources may have unreasonable joint ranges, incorrect installation directions, or joint axes that do not match the real mechanism. Check key joints one by one after import to avoid abnormal simulation behavior.

Joint Panel Preview

The joint panel shows joint name, current angle, minimum and maximum motion range, and a slider.

Operation: find the target joint in the joint panel -> drag the slider -> observe the corresponding part in the 3D view -> move to minimum and maximum positions to check direction and part interference.

Modify Joint Parameters

Operation: select a Joint in the structure tree -> view the right properties panel -> check or modify:

1. Parent Link and child Link.
2. Joint type.
3. Joint origin position and rotation.
4. Joint axis direction.
5. Minimum and maximum values.

After editing, return to the joint panel and preview the full motion range again.

Coordinate Frames and Joint Axis Display

Operation: open Detail Options -> enable "Show coordinate frame" and "Show joint axis" -> drag the slider to check whether actual motion matches the joint axis.

Use this when troubleshooting wrong joint motion direction, checking component installation direction, or comparing symmetric joints on both sides of a robot.

Modify Robot Appearance

Adjust Part Pose

Operation: select the target object -> edit Position X/Y/Z and Rotation parameters in the properties panel -> inspect from multiple views -> preview related joint motion.

Recommendations:

1. Record original values before editing.
2. Adjust only one direction at a time.
3. Link, visual geometry and collision body poses are independent.
4. After editing a visual model, check the collision body as well.

Edit Visual Geometry

Operation: expand a Link in the structure tree -> select visual geometry -> open the "Visual" tab in the properties panel -> inspect mesh file references -> adjust scale, position and rotation as needed -> return to the 3D view to confirm the result.

The image shows the properties panel for a visual geometry object, especially mesh file references, scale parameters and pose parameters. Mesh scale should usually stay consistent across X, Y and Z; changing only one direction may distort proportions.

Modify Color and Material

Change colors when you need to distinguish parts, mark a specific Link during debugging, create presentation images or prepare a resource cover.

Operation: select the specific visual geometry, not the Link -> open Visual properties -> modify the color or color value -> lower opacity if you want the part to appear semi-transparent for inspecting internal structure.

Color affects only model display. It does not change structure, collision bodies or physical parameters. If the model uses texture images, textures may override color settings.

Optimize Collision Bodies

Collision body complexity directly affects the computation cost of each simulation step. High-detail mesh collision bodies may reduce frame rate or make simulation unstable, so they are often replaced with simplified primitives such as boxes, spheres and cylinders. Collision bodies that are too simple reduce collision accuracy. The goal is to balance computation efficiency and accuracy.

View Collision Bodies

Operation: open Detail Options -> enable "Show collision body" -> optionally disable "Show visual" to view collision bodies alone -> inspect their positions and sizes from front, side and top views.

Select and Modify

Operation: expand a Link in the structure tree -> select a collision body -> inspect geometry, position and rotation parameters in the properties panel -> adjust size, position or direction as needed.

Optimization Tools

After optimization, check:

Check Physical and Hardware Parameters

Mass, center of mass and inertia directly determine robot behavior in physics simulation. Invalid inertia, such as zero, negative values or wrong orders of magnitude, may produce non-physical motion such as shaking, falling or flying apart.

Mass, Center of Mass and Inertia

Operation: open Detail Options -> enable "Show center of mass" and "Show inertia" -> select a Link in the structure tree -> inspect physical parameters in the properties panel.

Link Physical Parameters

Mass, center of mass and inertia should come from real design data or CAD data. For symmetric left and right parts, check whether parameters match.

Joint Physical Parameters

Operation: select a Link or Joint -> open physical properties -> edit based on reliable data -> display center of mass and inertia to check results -> export and verify in the target simulation environment.

Hardware Parameter Editing

Hardware parameters are platform extensions used to record robot actuator and transmission information. These parameters are not standard URDF fields and are usually included in CSV or BOM exports.

Operation: select the corresponding joint or part -> find the hardware properties area in the right properties panel -> fill in motor model and transmission parameters.

Hardware parameters should come from robot manuals or design files. If a value cannot be confirmed, leave it blank instead of guessing.

Part and Joint Operations

Create Link

Operation: click the "+" button at the top of the structure tree -> choose "Add Link" -> set the name -> add visual geometry (mesh and pose) -> add collision body -> fill in physical parameters -> create a Joint to connect it to the robot.

When creating a Link:

1. The Link name must not duplicate an existing object.
2. A new Link must be connected to the robot through a Joint.
3. A part that has only appearance but no collision body or physical parameters cannot support complete physics simulation.

Create Joint

Operation: click the "+" button at the top of the structure tree -> choose "Add Joint" -> set the name -> choose parent Link and child Link -> set joint type -> set joint origin, joint axis and motion range -> preview motion in the joint panel.

When creating a Joint:

1. Fixed-mounted components usually use Fixed joints.
2. Rotating joints should have reasonable motion ranges.
3. Preview the full motion process after creation.

Deletion Notes

Operation: select an object in the structure tree -> right-click it, or double-click in the control panel -> click Delete -> confirm whether child parts are included.

Deleting a Link also affects its child Links, Joints, visual models and collision bodies. Export a project backup before major deletion operations.

AI Review

Operation: click "AI" in the top toolbar -> enter AI Review -> choose a model -> start review -> read issues and suggestions -> confirm manually before editing.

After entering AI Review, the default mode is regular mode. Choose the intended use, format and type as needed, then click "Run check".

For a more comprehensive check, switch to professional mode, configure more detailed rules, then run the review.

After running the check, the page shows review progress. The review may take some time, so you can close the window and continue other work, then return later.

When AI Review finishes, it shows a report that can be downloaded and viewed.

AI Review is an auxiliary tool and does not replace manual inspection or simulation validation. Real hardware parameters such as mass, inertia and motor data should still come from reliable sources. Joint motion limits and collision bodies still require manual confirmation for the actual simulation task.

Auxiliary Tools

Measurement Tool

Operation: click the measurement tool in the top toolbar -> select two measurement points in the 3D view -> read the result -> exit measurement mode when finished.

Use it to measure robot height, arm span, sensor mounting distance and similar dimensions.

Source Code

Operation: click "Source code" in the top toolbar to download, copy or save source code.

Undo and Redo

The top toolbar provides Undo and Redo for reverting the previous action or restoring an undone action.

Model Snapshot

Operation: adjust the camera view -> set the display content -> click the snapshot feature in the top toolbar -> save the image locally.

Use snapshots to create resource covers, record before/after states or prepare project report images.

Dark Mode Toggle

Operation: click the dark-mode icon in the top toolbar to switch between dark mode and light mode.

Combine Robots and Components

URDF Studio supports importing multiple robots or components into the same workspace and creating connection relationships. Typical scenarios include mounting a gripper on a robotic arm, mounting an arm on a mobile base, adding sensors or combining multiple components.

What Is a Bridge Joint

A bridge joint is a Joint that connects two independent models. A normal Joint connects parent and child Links inside a single model, while a bridge joint spans two independently imported models and welds or articulates them together.

Bridge joint types follow the same choices as normal Joint types:

1. Fixed-mounted sensors usually use Fixed bridge joints.
2. Rotating connections, such as an arm mounted on a turntable, can use Revolute bridge joints.

Operation Steps

The following example installs a dexterous hand on a Unitree robot.

1. Import the robot body model and the dexterous hand model.
2. In the structure tree panel, find the bridge relationship area and click "Add". If the tree is long, scroll to the bottom or collapse nodes first.

There are two joint connection methods: geometric snapping and Link splicing.

Method 1: Geometric Snapping

In the bridge creation window, choose the joint type. To make later management easier, you can also name the bridge relationship.

Click the joint connection points on the two assets in sequence.

After both points are selected, the joint is connected automatically. If the pose is not ideal, adjust the bridge parameters.

After adjustment, click "Confirm" to save.

Method 2: Link Splicing

In the bridge creation window, choose the "Link list" tab.

Choose the joint type and fill in a bridge relationship name if needed.

Choose the base Link. If you do not know the Link name, select the object first and then check it in the structure tree.

Choose the child Link. As with the base Link, you can select an object in the 3D view and confirm its name in the structure tree.

Adjust bridge relationship parameters until the pose is correct, then click "Confirm" to save.

Validate the Assembly

After splicing, check the assembled state.

Recommended validation:

After validation passes, export the complete assembled model.

Recommendations:

1. Link and Joint names should not repeat across different models.
2. Fixed-mounted sensors usually use Fixed joints.
3. After installing a component, recheck overall mass and center of mass.
4. Export should include all referenced resources.

Export and Delivery

Supported Export Formats

Format quick reference:

Export Operation

Operation: top "File" -> "Export" -> choose format -> wait for export -> choose a save location.

After the export package is generated, choose a local save location and click "Save" to complete export.

Before export, check: complete structure -> normal joint motion -> no missing meshes or textures -> reasonable collision bodies -> no duplicate names -> complete referenced resources.

Connections With Other Products

BotWorld (get model) -> URDF Studio (inspect/edit/assemble) -> Export -> Simulation or publishing.

FAQ

When troubleshooting, use this order: file completeness -> model loaded correctly -> correct object selected -> reasonable parameters -> complete export content -> target software compatibility.

If you cannot solve an issue, submit feedback or leave a message in official BotWorld accounts on WeChat, Bilibili or Xiaohongshu. The official account name is "BotWorld".

Last updated: August 13, 2026.