javascript urdf-loader
Utilities for loading URDF files into THREE.js and a Web Component that loads and renders the model.
Demo here!
Use
<script src=".../URDFLoader.js"></script>
<script>
const manager = new THREE.LoadingManager();
const loader = new URDFLoader(manager);
loader.load(
'.../package/dir/',
'T12/urdf/T12.URDF',
robot => { },
(path, ext, done) => { },
);
</script>
Limitations
- Only
prismatic
, continuous
, revolute
, and fixed
joints are supported. - Collision tags are not parsed.
URDFLoader API
constructor(manager)
Constructor
manager : THREE.LoadingManager
THREE.LoadingManager. Used for transforming load URLs.
load(urdfpath, packages, onComplete, options)
Loads and builds the specified URDF robot in THREE.js
urdfpath : String
required
The path to the URDF file relative to the specified package directory.
packages : String | Object
required
The path representing the package://
directory(s) to load package://
relative files.
If the argument is a string, then it is used to replace the package://
prefix when loading geometry.
To specify multiple packages an object syntax is used defining the package name to the package path:
{
"package1": ".../path/to/package1",
"package2": ".../path/to/package2",
...
}
onComplete(robot) : Function
required
Callback that is called once the urdf robots have been loaded. The loaded robot is passed to the function.
See URDFRobot
documentation.
options : Object
optional
options.loadMeshCallback(pathToModel, fileExtension, onComplete) : Function
An optional function that can be used to override the default mesh loading functionality. The default loader is specified at URDFLoader.defaultMeshLoader
. onComplete
is called with the mesh once the geometry has been loaded.
options.fetchOptions : Object
An optional object with the set of options to pass to the fetch
function call used to load the URDF file.
workingPath : String
The path to load geometry relative to.
Defaults to the path relative to the loaded URDF file.
parse(urdfContent, packages, onComplete, options) : THREE.Object3D
Parses URDF content and returns the robot model.
urdfContent : String
required
The xml content of a URDF file.
packages : String | Object
required
See load
.
onComplete(robot) : Function
optional
Called immediately with the generated robot. This is the same object that is returned from the function.
Note that the link geometry will not necessarily have finished being processed when this is called.
See URDFRobot
documentation.
options : Object
See load
.
URDFRobot
Object that describes the URDF Robot. An extension of THREE.Object3D
.
name : String
The name of the robot described in the <robot>
tag.
links : Object
A dictionary of linkName : URDFLink
with all links in the robot.
joints : Object
A dictionary of jointName : URDFJoint
with all joints in the robot.
URDFJoint
An object representing a robot joint. An extension of THREE.Object3D
.
name : String
The name of the joint.
jointType : String
The type of joint. Can only be the URDF types of joints.
limit : Object
An object containing the lower
and upper
constraints for the joint.
axis : THREE.Vector3
The axis described for the joint.
angle : Number
readonly
The current position or angle for joint.
ignoreLimits : Boolean
Whether or not to ignore the joint limits when setting a the joint position.
setAngle(angle) | setOffset(position)
angle | position : Number
The position off of the starting position to rotate or move the joint to.
URDFLink
name
The name of the link.
urdf-viewer Element
<script href=".../urdf-viewer-element.js" />
<script>customElements.define('urdf-viewer', URDFViewer)</script>
<body>
<urdf-viewer package=".../package/dir/" urdf="T12/urdf/T12.URDF" up="Z+" display-shadow ambient-color="red"></urdf-viewer>
</body>
Attributes
package
Corresponds to the package
parameter in URDFLoader.load
. Supported are:
-
Single package:
// 1. Example for single package named `default_package`
<urdf-viewer package=".../path/to/default_package" ...></urdf-viewer>
Fallback within 1: If the target package within the package://
relative files do not match the default path it is assumed that the default path is the parent folder that contains the target package(s).
// 1. Example for single package named `default_package` with fallback:
<urdf-viewer package=".../path/to/parent" ...></urdf-viewer>
// since `parent` does not match `default_package`
// the path ".../path/to/parent/default_package" is assumed
-
Serialized package map:
E.g. if the meshes of a URDF are distributed over mutliple packages.
// 2. Example for serialized package map that contains `package1` and `package2`
<urdf-viewer package="package1:.../path/to/package1, package2:.../path/to/package1" ...></urdf-viewer>
urdf
Corresponds to the urdfpath
parameter in URDFLoader.load
.
The element uses fetch options { mode: 'cors', credentials: 'same-origin' }
to load the urdf file.
ignore-limits
Whether or not hte display should ignore the joint limits specified in the model when updating angles.
up
The axis to associate with "up" in THREE.js. Values can be [+-][XYZ].
display-shadow
Whether or not the render the shadow under the robot.
ambient-color
The color of the ambient light specified with css colors.
auto-redraw
Automatically redraw the model every frame instead of waiting to be dirtied.
Properties
All of the above attributes have corresponding camel case properties.
angles
Sets or gets the angles of the robot as a dictionary of joint-name
to radian
pairs.
Functions
setAngle(jointName, angle)
Sets the given joint to the provided angle in radians.
setAngles(jointDictionary)
Sets all joint names specified as keys to radian angle value.
redraw()
Dirty the renderer so the element will redraw next frame.
Events
'urdf-change'
Fires when the URDF has changed and a new one is starting to load.
'ignore-limits-change'
Fires when the ignore-limits
attribute changes.
'urdf-processed'
Fires when the URDF has finished loading and getting processed.
'geometry-loaded'
Fires when all the geometry has been fully loaded.
Running the Example
Install Node.js and NPM.
Run npm install
.
Run npm run server
.
Visit localhost:9080/javascript/example/
to view the page.
LICENSE
The software is available under the Apache V2.0 license.
Copyright © 2018 California Institute of Technology. ALL RIGHTS
RESERVED. United States Government Sponsorship Acknowledged. Any
commercial use must be negotiated with with Office of Technology
Transfer at the California Institute of Technology. This software may
be subject to U.S. export control laws. By accepting this software,
the user agrees to comply with all applicable U.S. export laws and
regulations. User has the responsibility to obtain export licenses,
or other export authority as may be required before exporting such
information to foreign countries or providing access to foreign
persons. Neither the name of Caltech nor its operating division, the
Jet Propulsion Laboratory, nor the names of its contributors may be
used to endorse or promote products derived from this software
without specific prior written permission.