Best Practices

To get the most out of LinkForge and ensure your robot simulations are stable and professional, follow these best practices.

Modeling for Physics

Physics engines like Gazebo or Bullet are highly sensitive to how geometry and mass are defined.

1. Scale and Units

  • Always use Meters: Blender can use various units, but ROS and URDF expect Meters. LinkForge automatically handles basic conversions, but modeling at a 1:1 scale in meters is the safest approach.

  • Apply Scale: Before creating links or joints, ensure all objects have an applied scale of (1, 1, 1). Select objects and press Ctrl+A > Scale.

2. Mesh Simplification

  • Collision vs. Visual: Use high-poly meshes for visuals, but always use simplified primitive shapes (Box, Cylinder, Sphere) for colliders. LinkForge allows you to set a primitive as the collision shape for a complex visual mesh.

  • Avoid β€œThin” Colliders: Very thin meshes (like a piece of paper) can cause tunneling errors in physics engines. Give your colliders some thickness.

3. Orientation

  • X-Forward, Z-Up: LinkForge uses direct 1:1 coordinate mapping (no automatic rotations). Following the ROS standard (X-axis forward, Y-axis left, Z-axis up) when modeling your robot in Blender will make joint configuration intuitive and match ROS expectations.

Modular XACRO Design

If you are building a complex robot (e.g., a quadruped or a high-DOF arm), modularity is key.

Use Macros for Repetition

Instead of defining 4 identical leg links manually, use LinkForge’s XACRO Export settings to group identical meshes.

Separation of Concerns

Consider organizing your robot into:

  • robot.xacro: The main assembly file.

  • materials.xacro: Centralized material definitions to ensure consistent colors.

  • constants.xacro: Store common values like PID gains or sensor offsets.

Performance Tips

Limit High-Quality Mesh Usage

Too many high-resolution meshes in a simulation will drop the Real-Time Factor (RTF). Use the Decimate Modifier in Blender to reduce triangle counts for your visual meshes before export.

Sensor Update Rates

Don’t set sensor update rates higher than necessary. A 100Hz LiDAR might be overkill for a slow-moving mobile robot and will consume unnecessary CPU cycles.

Control Configuration

Prefer Centralized Control

Use the centralized Control Dashboard to manage all joint interfaces. It provides a single view of all hardware configurations and ensures your ros2_control tags are generated correctly for modern Gazebo/ROS 2 integration.

Data Preservation

Importing Robots

When importing an existing robot (URDF/XACRO), LinkForge automatically disables Auto-Calculate Inertia to preserve your original, scientifically calibrated inertia tensors. Do not re-enable this checkmark unless you have modified the geometry significantly and want LinkForge to re-approximate the physics properties.