reaction diffusion effect (abstract growth effect)

[gomeslindsay]

hello

I wanted to know how to get this reaction diffusion effect or any abstract random growth effect in Arnold

something like this video

and how do you add another texture to it or 2 textures one the object and the other the growth

https://www.youtube.com/watch?v=mYsfWAReOQg

[lee_griggs]

The video shows a displacement map with two shaders layered together (layer or mix_shader), with the displacement map also used as the mix_weight of the mix_shader.