Hello! I want to make a fracture in a mirror in my scene, but most tutorials seem to show only how you break the entire model. I simply want to make a fracture mark where a fist has hit the mirror.
This is pretty much exactly what i am looking for.
Also, i would really appreciate if someone told me how to add the blood + dirt/toothpaste stains on the mirror (which means multiple different textures)
Thanks!
Hey 
You might want to try out the Fracture Modifier (FM) Build of Blender.
For further info see the “official” support thread:
https://blenderartists.org/forum/showthread.php?343637-Custom-Build-Blender-Fracture-Modifier
I tried to make an example blend (works only in the FM build), here a sample render.
It utilizes the FM with greasepencil + uniform pointsource, constraints, triggering and autohide with an autohide
filter group to reveal glass cracks selectively. (filter objects can use only radii atm, so only circular shapes for crack
revelation.)
Autohide generally looks like this:
A general introduction into FM could be found here:
And here the example blend:
glassbreak1.blend (1.92 MB)
Open with the 2.78c FM build (download links in the thread linked above) and run the animation (Alt A).
Autohide effect is working best with glass, so check out the rendered view.
