How-to: Customize Joint Visualization

LinkForge provides semantic visual feedback in the viewport to help you verify robot kinematics instantly.

1. The XYZ Frame

When a joint is created, LinkForge renders a small coordinate frame at the joint origin:

  • Red: X-Axis

  • Green: Y-Axis

  • Blue: Z-Axis

2. Quick Viewport Overlays (Forge Panel)

Starting in LinkForge 1.5.3+, you can manage viewport visual clarity without opening Preferences. In the Forge tab (Step 1), the Viewport Overlays box provides instant controls:

  • Collisions: One-click toggle to show/hide all robot collision meshes (hidden by default).

  • Joints: Toggle visibility of all joint coordinate frames and arrow empties.

  • Inertia: Toggle Center of Mass and principal inertia tensor visualizations.

  • Fit Gizmos to Robot: Automatically calculates the robot’s bounding box and scales all gizmos proportionally to fit the robot’s physical dimensions (clamped between 5mm and 50cm).

  • Size Slider: Live slider to dynamically adjust joint gizmo sizes.

3. Global Visualization Settings (Preferences)

Fine-grained visualization settings are managed in Blender Preferences:

  1. Open Blender Preferences (Edit > Preferences).

  2. Go to the Add-ons (or Extensions) tab and find LinkForge.

  3. Locate the Joint Visualization section.

Unified Sizing

The Joint Size slider is a master control for your viewport clarity:

  • Empty Arrows: Adjusts the physical size of standard Blender joint markers.

  • Enhanced Overlay: Simultaneously scales the length of the high-visibility GPU arrows.

  • Default Scale: Defaults to 0.05m (down from 0.1m) for a cleaner initial viewport.

Progressive Disclosure (Display Mode)

To keep complex robots with dozens of kinematic links readable:

  • All Joints: Renders coordinate frames for every joint across the robot hierarchy simultaneously.

  • Selected Only: Renders joint coordinate frames exclusively for the actively selected link, keeping the rest of the robot visually clean.

Depth Testing & Occlusion (Depth Mode)

  • Always On Top (X-Ray): Joint frames remain fully visible even when located inside opaque robot meshes.

  • Occluded by Meshes: Uses hardware depth buffer testing (LESS_EQUAL) so joint frames are hidden behind external robot geometry, preventing visual confusion on closed structures.

Enhanced GPU Overlay (RViz-style)

For a professional robotics look matching ROS/RViz:

  1. Check Enhanced Visualization (RViz-style) in preferences.

  2. This draws refined 2.5px red/green/blue arrows with directional cones.

  3. Automatically respects the Joint Size and Occlusion Mode settings.

4. Cleaning the View

To hide all LinkForge markers for a final render or clean presentation:

  • Toggle the Joints button in the Forge > Viewport Overlays box.

  • Or use Blender’s standard Hide Extras toggle in the Viewport Overlays menu (top right of the 3D View). Since LinkForge joints are standard Empty objects, hiding “Extras” hides all joint, link, and sensor markers instantly.