Assets Geometric Fur Shells

Shells is an old trick used to create the illusion of hairs & furs on a model.



It's usually done within a fragment shader. However if you export the 3D model and use it in another app or viewer (for example in Sketchfab), you can't change the shader used.

You can however do it within the geometry. If you duplicate the mesh in the upward direction, rescale it a bit, and apply a texture with an alpha value in it, you can create the illusion of hair strands.

The repo is here: https://github.com/Pseudopode/UnityFurShells

 

This Looks interesting. I will have a look if I can use it for my large grass areas

PS: It is really Looking great and can can very useful for single animals etc. but for grass it is way to expensive this way. But interesting find, thanks for sharing!

 

@Firlefanz73 one (old) way to do it, without being too costly, is with a parallax shader, like the technique here : https://www.cg.tuwien.ac.at/research/publications/2007/Habel_2007_IAG/ (Instant Animated Grass).
The slides are here : https://pdfs.semanticscholar.org/3fc4/e6b0ac5566c0e40c16e9c3542f069d99888a.pdf

I have taken a few screenshots to illustrate the technique :

 

Thanks a lot for the idea! There are plenty gras shaders like this I gues...

I thought of having some kind of I don't know "distortion" shader.
I once bought one but it was depricated and was too perforance expensive.
The Input was a grass Ground texture and some Kind of noise texture.

The effect looked extremly like your effect, but it was done by one material with one shader.

I first thought your solution was something like this, but your way is interesting, too
Although too slow at least for me in my chunk Environment with much grass...

 

A quick update on the POC.
I changed the way the transparent shells and the base colors are added.
I'm bringing here two screenshots, with different base textures, giving two different aspects.
Thhe image on the left showcase a 'fluffy' aspect, and the image on the right a more 'spiky' one (this image is in fact from the original POC).

The difference is from the alpha of the tex. What do you think ?