Realistic Mirror fracture?

As far as I know a mirror is rather complex.
It has a glass plate with a “painted” reflective surface on the back, and the backside of that is usually painted black or brown.

This can be modeled it two parts; the glass, and the back plate with respective UV map for black and reflective sides.

But how would a Cell fracture treat such object as a complete piece?
When a broken mirror falls on the floor, you would see both front and back parts…

It works fine. The glass object would consists of 2 materials. Glass and the back. However the key is to have the back material a MIX SHADER of two shaders, a ‘metallic gloss’ and a diffuse ‘black’ which use a geometry channel of the objects ‘backface’ to determine which shader goes on which side:

The red and black checker pattern in this image is what shows on the back of the mirror, and the ‘reflection’ is a 100% glossy shader acting like a mirror on the reverse side of the backface. This is a viewport snapshot. I’ll upload the file when I’ve a spare moment.

Ah, thank you very much, DaminanJ!

The geometry channel is the magic of it I see :wink:

EDIT: I made a material like this, and used a quick BW mask to separate back face from the rest of the object. I’m sure the mask could have been made procedurally just as good, but UV mapping the object was necessary to place the backface on the correct location of the mask.

As I applied the material before generating the fracture I simply assigned the bottom face with the ‘backfacing’ material and then inverted the selection and assigned the other faces of the object to the ‘glass’ material. The fracture object then uses this. If your material works . . perfect :slight_smile: