Simulate Rim or Bevel on a Flat Object's Border?

[MumuMundo]

Hello,

I’m using low poly flat objects to make 2D rigs. Why not use Grease Pencil ? Because it’s limited in many ways when it comes to rigging.

My question is about how to simulate a bump in my flat objects to get a rim light or any other method that can give me the same effect.

For example there’s this old thread where someone was trying to do the same but he didn’t explain how he did it :

2d Cartoon RimLighting in Blender

So I have been using a trick to get 2d characters to work in a 3d world. By using the alpha channel of the 2d animation and offsetting it you can get a nice rim lighting for free! Normally I do this in after effects when comping the characters in. But for this next project I would like to import the 2d animation as a plane and have the rim lighting work as an eevee shader. And I need some more reliable way to warp the UV “away” from the illumination to get the nice sharp…

I tried with gradients in the nodes system but couldn’t get a gradient to follow the edges of my flat shapes.

[SterlingRoth]

@PBnSmoothies

By using the alpha channel of the 2d animation and offsetting it you can get a nice rim lighting for free!

he says exactly what he did.

[MumuMundo]

There he was talking about the process in AE. Thanks anyway.

[MumuMundo]

You can see demos of the 2D head I’m working on in my Twitter :
https://twitter.com/mumu_mundo/status/1568646162407628800
https://twitter.com/mumu_mundo/status/1570762038384930817

This is what I achieved so far with limited knowledge in shading :

[MumuMundo]

It works (somehow) because I unwrapped my flat object like this :

[PBnSmoothies]

So my process relied on the alpha channel, since these are geometry you’re not going to be able to use a similar trick.

If you are in cycles the “bevel” node on the normal will produce a small rim effect.