How do I create cracks on this model?

I’m modeling my wireless mouse. and this is the real life picture of it:

I’ve finished the base shape:

But if you noticed it, there’re cracks around the upper face, on the middle of the mouse and between the left and right buttons. What do you think is the best way to create these cracks? I’ve tried creating them by directly using extrusion, but since I’m using subsurf modifier, it creates soft cracks, (more like cutting into ice-cream). But what I want is hard, uniform, clean cracks like shown in the photo.

They are so tiny, I’d just make a normal map for them. I don’t think there is any need to model them. They are barely visible in the picture.

If you want to model them you can still use the extrude with the subsurf modifier. Then you have two options:

  • insert additional loops to sharpen those edges or
  • you can select them and in the edge menu (Ctrl+E) select mark sharp and use the edge split modifier with the sharp edges option

another way could be to split the face in those areas by selecting the edges and pressing “V”, it will open a crack on the edges and you can then extrude them down (Im not sure if with this option you will face the same smooth problem and have to solve it as above).

another option would be to use the existing model as a form, and use the retopo tool to extrude a new mesh over it, with the topology taking into consideration the grooves or segments. retopo still works better in 2.49 as far as I know, btw.

I’ve tried many methods to achieve the effect I want while keeping the topology simple. But the best of them I think is using Bmesh, because the automatically sub-divided 5 or 6 sided polygons can generate very good topology lines, using only as few vertices as possible.


Render Result (Cycle):