Pity this thread seems to be dead - I think I’ve come up with a super cool way to shatter glass with visible crack propagation!
I’m thinking of doing a slowmo animation of a bullet hitting a wine glass (with wine inside!). Here is how it works.
Remember how we said that blender doesn’t model in solids? Well, it can do - using the new boolean modifiers. You can use the boolean modifier to shatter an object with real geometry for the pieces, then you can “seperate all loose parts”. Now we have loads of fragments, we can apply the physics engine and bake the animation to IPOs. This was brought up recently - I think it is possible to assign physical properties to the pieces en mass.
Now for the cool bit - if we have a transparent glass and we have split it up into real geometry pieces, the internal faces will show up on rendering as ugly cracks even before shattering. Here is my solution:
After the boolean operation when the whole thing is still one object, using the new build in the CVS, select all the linked flat faces on the surface. Now invert the selection to get the internal faces which are a pain. Assign a new material index to them.
Now the thing I discovered for myself - the material indices are correcly retained across all the objects after splitting. Now for my final inspiration, apply a blend texture as an alpha channel using “object” coordinates with respect to an animated empty. As the animated empty approaches the point of fracture, the cracks begin to propagate outwards.
Finally, with the new animated obstacles in the CVS, you could fill the glass with wine and simulate - now we have collision between the glass pieces and between the glass and fluid. And everything is real geometry.
What do you think?