Help needed. How to make chewing gum stretch

On a real hot day have you ever stepped on a piece of chewing gum that sticks to the ground and the bottom of your shoe?

I’m doing an animation where the character does exactly that. He doesn’t see the gum and steps on it and gets stuck to it.

I tried a lattice but there’s not enough control for the various directions the foot will move to.

Then I tried shapes - much better, very good control, and then I started wondering. Is it possible to have a layer of vertices in the gum maybe parented to the bottom of the show or hooks so the gum follows the bottom of the foot? While the top layer of the gum that is stuck to the bottom of the foot follows the foot, the gum stretches - gets thin in the middle.

Maybe a combination of shapes and constraints.

I’d appreciate your help with this.

YOu could use stretch to bone constraint.

For anyone interested - I’ve tried the stretch contraint and the hook/ shape combination. I just could not get enough control so I stuck with shapes. It’s a lot easier than I thought.

What I found what works best is working with five shapes.

the main shape is the gum stretched staight up on it’s vertical access. the other four are stretched on the x and y axsis in both directoins (No Z axis) . Then using a combination of the shapes I key frame the locatoin of the shoe to match the the gum.

Here’s a rough sample - after I finish my character and rig and texture it. I’ll smooth out the coordination of shoe/gum.

How about using a bone for the stretch and making the bone an IP driver for a shape key to give you your gummy narrowing in the middle? At least that way you could have the bone/gum follow the shoe rather than having to position your shoe over the gum.

I treid the bone combo but can’t seem to get the shape to trigger.

I linked the bone to the top vertices of the gum and then did a driven IPO for the stretch shape using the same bone. The driver uses the bone in pose mode and LOC Z .

But I’m not getting any thinness.

Any thoughts on this?

The animation with shapes looks pretty good, except at the highest point the gum seems to separate from the shoe. I think some hooks on the top vertices of the gum would fix that (though I’m not sure how they would interact with the shape keys). To the hook empty add a Copylocation constraint targeting the shoe, and keyframe the Influence from zero to one when the shoe contacts the gum.

CD38 - This was a quick test to the feasibility of what method to use. Yes you are correct.

As to hooks and driven shapes - I’ve given up on them. The scene will be about 2 to 3 minutes long. By the time I figure out how to coordinate the hooks or bones I can key frame the shoe location and shapes, adjusting it along the way. So unless someone can send me a blend file with a solution using hooks or bones with driven shapes I’m sticking to key framing with shapes.

Thanks for your suggestions.