Hi, everyone. I`m a new fan to houdini, I ran into a problem when I tried to create an effect like breaking a rock into pieces. I used shatter tool to fracture a rock and made it RBD fractured object, it reacted well when it hit the floor and broke into pieces,and some pieces bounced up nicely ,but what I want is I want the pieces which bounced up to break into small pieces again when they hit the floor for the second time, how can I achieve that kind of effect, any idea would be very appreciate.

One easy way is using a Make Breakable from the Rigid Bodies shelf,
it will insert a voronoi fracture configure object node in the autodopnetwork.

Thanks very much,blonde It`s a really easy and efficient way to crash something!

prefracturing is a artistic way to control the fracture behaviour. But what if I want to have also the artistic control of a second or third fracture. The makebreakable tool doesn't work for such things right?

prefracturing is a artistic way to control the fracture behaviour. But what if I want to have also the artistic control of a second or third fracture. The makebreakable tool doesn't work for such things right?

Correct. Thats why you need to look at building your own tool

Rob

roughsporty
prefracturing is a artistic way to control the fracture behaviour. But what if I want to have also the artistic control of a second or third fracture. The makebreakable tool doesn't work for such things right?

You certainly get more control from pre-fracturing, although there are some settings on the “fractureparms” node you can tweak to get more control of dynamic fracturing.

Basically everything on the “Impact” tab of that node is a filter, with most parameters causing things not to fracture, i.e. all the conditions have to be met for a fracture to occur.

All of the parameters can be set on a per object basis using expressions or groups, so you can delay fracturing until an object is below a certain height, or only when it hits a certain object, etc.

I put an example file here [forums.odforce.net] that shows some more advanced uses of these parameters. In particular there's one that shows using the Break tool and RBD Glue Object for the primary fracture, then dynamic fracturing only on the pieces, with a couple of ways of limiting when the secondary fractures occur.