4.0 KiB
@xviz/ros
The @xviz/ros provides support for reading ROS Bags and convertring ROS Messages into XVIZ data.
This module will support the following:
- Reading ROS Bag files
- A configuration based conversion workflow
- Custom message conversion
- Off-line conversion
- Run-time conversion
The focus is on ROS 1, but most if not all of this translates to ROS 2 as well.
Examples
See our code examples:
Access to ROS data
At the lowest level we need to read ROS Bag files and covert the messages to XVIZ. This is achieved with the ROSBag class to read ROS bags, and a set of Converters to managed turning ROS message into XVIZ.
Convertering ROS messages to XVIZ
In order to provide control for how this mapping happens and conversion support for ROS messages we may not support, we provide the classes ROSConfig and ROS2XVIZConverter.
The ROSConfig allows the selection of specific topics along with the ability to have some control over how that mapping happens. Placing the topic to converter mapping, along with converter options, in a single configuration will hopefully make utilizing ROS data easier.
The ROS2XVIZConverter serves as a repository for registered Converters and will dispatch messages to the conversion along with any options set in the configuration. This allows for custom conversion classes to be registered and used.
Integrating with the XVIZ eco-system
In order to allow ROS data to work across our other tools, we encapsulate the details in the ROSBagProvider. This provider allows our tooling that operates on the Providers abstraction to work with ROS data seamlessly.
This requires the use of the ROS2XVIZFactory which enables the instantiation of a ROS2XVIZConverter at a later time.
Module Classes and Objects
Converters
Converters are the classes that read the ROS topic message and convert to XVIZ.
ROS2XVIZConverter
ROS2XVIZConverter is the class manages calling the proper converter for a specific message. It must know the available Converters as the ROSConfig
ROSConfig
The ROSConfig defines a schema used to describe the mapping from ROS Topics to a Converter. Normally messages are mapped by the ROS message type but custom converters can be chosen to override the default.
In addition options for the converter can be specified in the configuration.
ROSBag
The ROSBag class provides access to the ROS messages and data.
This class can be subclassed to provide validation and additonal context for your custom conversion requirements.
This class is used by the ROSBagProvider to read messages and have them convertered into XVIZ.
ROS2XVIZFactory
The ROS2XVIZFactory holds on to a set of Converters that will be used to construct a ROS2XVIZConverter.
ROSBagProvider
The ROSBagProvider provides a high-level interface to accessing XVIZ data from a ROSBag. It requires the classes described above to manage access to the ROS bag data, mapping of topics to converters, and the actual conversion process.