📏 Link#

We refer to the rigid components in a multibody system as links. In MotrixSim, a link is an important concept representing each rigid part of a multibody system. Each link can have different properties and behaviors, and is connected to other links via joints.

link

MJCF Mapping#

When you use MJCF to describe a multibody system, MotrixSim maps all <body> elements to Link objects.

For the current support status of <body> tag attributes in MJCF, see MJCF Support Status.

Note

The <worldbody> element in MJCF is not treated as a Link object.

Main Interfaces#

In MotrixSim, you can access Link objects as follows:

model.num_links: Get the number of Link objects in the current world.
model.links: Get all Link objects in the current world.
model.get_link(key): Get a specific Link object by name or index.

Once you have a Link object, you can manipulate it using a variety of properties and methods. For more detailed APIs, refer to the Link API.

Example#

You can run a simple example demonstrating link API usage with:

uv run examples/physics/link.py

See the source code at examples/physics/link.py.

API Reference#

For more APIs related to Link, see Link API