# Worms crawling under skin

I wanted to create a scene where you can see a worm crawling underneath the skin of a person's belly.

I've tried it with the tools provided in Blender like the deform modifiers (mostly I tried with Cast modifier, warp modifier and partially the displace modifier) but it just doesn't look like a worm.

The cast and warp modifier do not support custom shapes, only the basic sphere, cube and cylinder.

Does anybody know how I can achieve this result? I also tried with softbody physics, but that didn't really work out well when pushing a collision from the inside, especially because the shape didn't really come through.

Is there any way I can get the form of a more abstract shape seen and shaped through another object without using shapekeys?

The whole scene is CG, so it isn't about a real video where I want a CG worm to crawl underneath the skin; its just a CG character.

• Is the whole scene CG or do you want to do VFX with real video footage? – Robert Gützkow Sep 19 '19 at 8:32
• Just CG. No real video footage :) – DevilNaiden Sep 19 '19 at 8:37

You could use the Vertex Weigh Proximity modifier to control displacement. It will use the actual shape of the mesh to correctly displace the surface.

Create a new vertex group in your "skin" mesh and add all vertex to it with a strength of $$1$$. Now add a new Vertex Weigh Proximity modifier, pick that vertex group, set the "Worm" mesh as Target Object and make sure to set the Distance Mode to Geometry.

After that add a Displacement modifier with weight affected by the previously mentioned vertex group. No texture is required (although you can optionally add one), just adjust strength and displacement distance values as necessary.

You can move your worm mesh around and it will deform according to both position and shape.

• That is exactly what I was looking for. Thank you! :D – DevilNaiden Sep 19 '19 at 10:29
• Got that working and added a Lattice for the worm to "compress/decompress" through and it looks truly creepy, wiggling along. – rob Sep 19 '19 at 12:01
• @rob do post a screencap of the effect! – John Dvorak Sep 20 '19 at 11:28
• I joined just to say that you made an impressive work. It looks so easy, even for someone who never used blender. However, I must say this: that is SO CREEPY! I actually feel real itching on my skin from this. Thank you 👍. – Ismael Miguel Sep 20 '19 at 17:05
• @DuarteFarrajotaRamos Wow, you have LOTS of tricks up your sleeves. – Rita Geraghty stands by Monica Oct 21 '19 at 17:36

Have you tried with Lattice? Not easy to manipulate though...

• Create a plane, subdivide it. Create a lattice above your plane. Give your plane a Lattice modifier with the lattice as Object.

• Move the lattice vertices so that it deforms the plane the way you want. Create some shapekeys if you want this shape to change over time. Move it over the plane. You'll probably need a Subsurf above and one below the Lattice modifier to have a smooth bump.

• Thanks for your answer. It actually does work okay. It is hard to get the correct form, but it should work for something as simple as a worm! – DevilNaiden Sep 19 '19 at 9:52
• maybe Duarte's answer works better ;) – moonboots Sep 19 '19 at 9:54
• It did. Still thank you for spending your time and telling me about a possible solution :) – DevilNaiden Sep 19 '19 at 11:00