I'm on Blender 2.79. When using drivers on node properties the material doesn't update on the Rendered/Material viewports until I force reload it.
My drivers are pulling custom object properties from a parent armature and running it through a scripted expression. This driver's output is then fed into the Y Scale of a Mapping node. It works wonderfully, the value updates immediately, but the viewport doesn't.
After changing the parent's custom property, the driver updates, the node value updates, but the material in the viewport doesn't:
After I hit
SHIFT+Z twice to exit and reenter the Rendered mode, the material updates:
Another way to force the viewport update is to make a manual change to the material, like disconnecting a random node or changing the texture location, or to the drivers, as changing the type of a second driver. But automatically? No success so far.
What am I doing wrong?