🔹 Drivers in Blender
A Driver is like a mini script or connection that controls one property using another property.
👉 Example:
You rotate a bone → another bone’s scale changes automatically.
You move a slider → eyelids close automatically.
How it works:
A Driver connects a target property (what’s being controlled) to a source property (the controller).
You can use math, variables, or expressions to define the relationship.
Uses in Rigging:
Make bones follow or rotate automatically.
Eye blink or jaw movement controlled by a single slider.
Gears that rotate together (one driver drives the other).
🔹 Custom Properties in Blender
A Custom Property is a user-defined value you can add to an object, bone, or rig.
It’s basically a slider, checkbox, or number you create to help control things.
👉 Example:
A slider called “Smile” (0–1) that drives facial blend shapes.
A toggle (On/Off) for IK/FK switching.
A float value for controlling “Muscle bulge” strength.
How it works:
Add a custom property to a bone/object.
Then use a Driver to connect that property to other things (like shape keys, transforms, modifiers).
🔹 Drivers + Custom Properties Together
This is where Blender rigs get really powerful:
You create Custom Properties (sliders, toggles, etc.) → easy controls for animators.
Behind the scenes, Drivers connect those properties to actual rig elements.
👉 Example:
A “Head Tilt” slider (custom property) → driver rotates the head bone.
A “Smile” slider → driver activates mouth shape key + cheek bones.
IK/FK Switch button → drivers control which system is active.
âś… In short:
Drivers = rules that automatically control one property with another (automation).
Custom Properties = user-made sliders/values that can be used as animator-friendly controls.
Together, they make rigs powerful, clean, and animator-friendly
