Xacro Macros

LinkForge provides out-of-the-box support for exporting robots with modular Xacro (XML Macros) capabilities.

Xacro Support

Xacro allows you to build modular and parameterizable URDF files. LinkForge’s export pipeline natively resolves Xacro properties and mathematical expressions.

Programmatic Usage

You can define Xacro properties and use them in your mathematical expressions when building a robot programmatically:

from linkforge.core import RobotBuilder, box

builder = RobotBuilder("xacro_robot")

# Define a global property
builder.robot.properties["chassis_mass"] = "5.0"
builder.robot.properties["chassis_length"] = "0.4"

# Use expressions in physics or dimensions
builder.link("chassis") \
    .visual(box("${chassis_length}", 0.3, 0.1)) \
    .mass("${chassis_mass}") \
    .root()

When you call .export_urdf(), the file will be generated as a compliant <robot xmlns:xacro="http://www.ros.org/wiki/xacro"> and any un-evaluated expressions will be preserved for the xacro command-line tool.