Increasing Fracture Density Over Time?

[Atom]

Hi All,

 

I recently went back and re-did the fracturing pillars tutorial. This was my first introduction to Houdini. As I went through the tutorial I got to the end where the ball swings and smashes the pillars and something odd happened. The pillars started fracturing under their own weight even before the wrecking ball came in contact. I thought this was cool and I wanted to try and re-create that effect but I am having some trouble. I can't seem to reproduce that effect.

 

Is there a way to make objects fracture under their own weight?

 

I have tried animating the density parameter but that seems to have no effect (maybe a SetInitial somewhere instead of a Set Always...?)

 

I would like the fracture to start off slow and then completely collapse under the object's own weight.

[Farmfield]

Ooh, awesome topic, Atom. For doing fracturing feedback loops, the workflow using volumebreaker in Thinking Particles is just genius - here's some RnD I did for a short last summer...

 

 

And of course this must be possible to replicate in Houdini. The only question is, what way is the best/easiest way to do it. I'm thinking something like a SOP solver setup using the measure SOP and creating rules through filtering trough attribute values out of the sim for determining if/when/what fragments refracture in the DOP...