I want to create like this model
I know it is just a cube with a normal map, but i want to know how to make the broken edges.
The broken edges are probably really craved to the final model with the least vertex count possible. It is just pure geometry manipulation, with a bit of an artistic touch.
If you’re not concerned about polycount you could just model the perfect tiles in very hi-poly and sculpt chips and cracks into it.
After that you can choose to either bake to lowpoly or use decimate modifier and clean it up manually afterwards, or just leave it hi-poly.
The chips and cracks were not modeled at all. They are just part of the texture. It is usually a waste of time to model tiny details like that. Just use texture.
you model it with extrude, grab, and fill.
that’s really all there is to be said.