Soft Feet + {

I did a little more work on the Beast's Soft Feet and thought I'd post the result. The goal was to make the nail extending and retracting more true to a realistic cat paw.

• The model needed to be changed to adapt to the improved rig. 
• The nail needed to pivot around the toe joint accurately. 
• The surrounding skin needed to react to the nail.

This was my reference for the nail pivot:

The nail pivot was a simple matter of adding a bone or 2 to the end of the nail to use to pivot the nail. The trick was getting the skin to wrap around the nail as it extends and retracts. For this I decided nCloth was the best bet to get a realistic effect.

Skin Cinch {

I didn't want to simulate the entire mesh, since I wanted the skin around the nail to have really accurate collision (high settings). So I created a cinch around the nail. The cinch is an nCloth with dynamic constraints for maintaining transforms and attracting toward the nail. The nail is a passive collider for the skin cinch, so it never penetrates the nail itself. I then use the cinch as an influence on the actual mesh. This avoids simulating the entire mesh and focuses the simulation on the area that matters.

Comment below to ask questions or give feedback! Hope this helps!

-K