Hi,

I am trying to set up a scene that allows me to break something at the moment of impact.

Using a flat thick object standing up, like a glass window for instance, I have set it up like so:

Used the Model shelf tool “Shatter”, adjusted the settings to my liking.

Applied the Rigid Body shelf tool RBD Fracture.

When I hit play my “window” just falls into pieces from the start of the animation.

So if I send something through it, like a RBD Object applied to a sphere with velocity, it does not wait for that to hit before crashing down.

I have searched through all of the node networks for a parameter to start the dynamics by collision and I can't seem to find anything.

Did I miss it?

Another related question is, what is the best way to limit the area of shatter/fracture to a specific area of the mesh?

Thanks.

SOLUTION:

Don't prefracture.

Set your scene with dynamics. Apply the appropriate RBD type to each object.

Select the glass object in the dops network and then select Make Breakable from the RBD shelf, select the Window object in the viewport and press Enter. This will create a “fractureparms” node below the glass object.

More details from there of course. But that is at least the basic set up to get it to fracture on impact and you can then adjust other things like the radius of the impact and so on.

Hi,
Just in case you still want to achieve activating rbd object based on collision on a prefractured object here is a technique I am using so far. I kno this is not really collision perse. But it will allow you to decide when and what gets active, so it could be useful.

Basically everything in controlled in the DOP network through a activateValue node. This node basically tells the sim if the piece is active or not. I link the value to a color attribute I create on the fractured object, and set it to setAllways.

See the example for more details…

If anyone has a better method I will be curious to hear it. but this one seems pretty reliable.