Ever wonder how can you model this?

This is call displacement in rhino modelling language. Some modelers prefer to do it through the material rendering engine and others prefer to model it.

applydisplacement-002

Learn how to create displaced mesh objects using procedural textures in Rhino 5. Displacements can be used for rendering purposes or extracted and edited for fabrication.

This is a good tutorial to get you started:

Also this one: