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

Soft Feet {

I'm currently working on adding details to a quadruped rig from my senior thesis film "Gauntlet". I didn't get as much time as I wanted rigging him, so I decided I'd enhance a few parts. One part that bothered me about this character was his feet's interaction with the ground. So I set out to fix it by adding deformation to the foot to simulate the pads squishing on the ground. The animator can get the foot relatively realistic and with minimal clipping, but having a touch of deformation sells the impact.

The simple approach would have been to just create some NURB deformers and give the animator control of the squash and stretch of the foot. However this would add even more work to the poor animator who is tasked with a walk cycle of a quadruped. So I decided an automated/simulated solution was ideal in this scenario.

Now I needed to avoid the messiness and expense of making the entire body into an nCloth. The body mesh is quite high poly, and I only wanted to simulate the feet. Thus, I decided to only simulate the pads of the foot and use those as influences on the main mesh. The pads are extremely low poly, so they simulate almost real-time. And they also more correctly describe the foot of a lion (my inspiration for the feet). The one trick here is to make sure you check on "Use Components" in the skinCluster of the main mesh being influenced. This means it will use the components of the influence object and not just its transform.

Here is a quick video showing the deformation effect:




And here's one on a more bumpy surface (it is simulated after all):


So, to replicate, follow these steps: