Clearer Color On Cube Edges

Hi !

I am new to Unity and I try to acheive a certain rendering for my project. So, I want to create some "tiles" for my game and I want that the design looks like something like the effect on the edges of the dirt on the following image from the game Suzy Cube.



After some researches, I found something that has to do with baked Ambient Occlusion but I'm not sure and I don't know how to achieve this and if I need to do it directly in Unity or before in Blender. Or maybe it's just a simple texture.

I will really appreciate if you can help me and give me some hints. It's maybe obvious but I told you, I'm very new to Unity and 3d design in general

Thanks !

 

It's a simple texture