I can see you're interested in learning more about the rigging process for that interesting facial orientation setup! This is a really clever technique for creating faces that can turn in different directions.
Understanding the Setup
This rig creates a 2.5D depth effect that allows a face to appear to turn while maintaining a flat, illustrative style. Here's how it works in more detail:
The Core Concept
The technique uses transform constraints to create opposing bone movements. Here's the breakdown:
Three main bones: You need a parent bone (like head), a control bone (control), and a target bone (control-back)
Transform constraint setup: The control-back bone uses a transform constraint that follows the control bone with a translation mix set to -100%. This makes it move in the exact opposite direction of the control bone.
Mesh weighting: The facial mesh is weighted to all three bones:
- The center/middle vertices are weighted to the
control bone
- The outer edge vertices are weighted to the
control-back bone
- The base weight goes to the parent
head bone
The Painting Process
When weighting the mesh:
- Start with all vertices at 100% influence from the
head bone (neutral state)
- Use weight painting in additive mode to paint the middle vertices to be influenced by
control
- Paint the outer edge vertices to be influenced by
control-back
- This creates concentric rings of influence that simulate a spherical surface
For a detailed video tutorial showing the complete rigging process for both round and angular versions of this technique, check out this stream:
You can also download example projects to study the setup directly from http://esotericsoftware.com/spine-twitch.php
