Submitting objects to Dops

[WesleyE]

Hi,

I am creating an cracking effect where a crack starts forming on a RBD object. When a crack has seperated the object, it should become a seperate RBD object so that it can fall off.

The whole cracking and seperating the objects works, but when I send the new pieces to DOPS, they simply wont show up. I've got "Use deforming geometry" set to on, but that still does not import the new pieces.

I've included my project file, can someone point me in the right direction?

WindowShatter.zip

[WesleyE]

Maybe I should clarify

I've got a SOP that on frame 1, has only one piece, but contains about 300 pieces at frame 300. How can I make sure that DOP's simulates the new pieces as they become available? Right now, every piece that is not in the sim at frame 1, simply disappears and does not get simulated.

[ryew]

I haven't looked at your scene, but if the source objects you are feeding into DOPs for simulation are changing from one frame to the next, it's not going to know what to do with them.

If you have specific cracking you want to occur, you might want to start with the completely pre-fractured geometry and then activate the pieces to control the active versus passive objects. Otherwise, you can give dynamic fracturing with the unbroken geometry a shot.

The bullet solver tutorial on the SideFX website explains both workflows.

[WesleyE]

The cracks are growing on the surface, and when the crack has one whole piece seperated, it will fall off. That new piece is supposed to get plugged in to dops to simulate it. The new piece does get a new name attribute automatically, but dops still won't pick it up. Since the cracks are growing, I can't 'prefracture' the object since there arent supposed to be multiple pieces in the beginning of the sim.

[DanBode]

I didn't get a chance to look at your file, but Dops only really cares what geometry is present in sops on a creation frame.

1) In Sops make it so you have a sop that on each frame only contains the geometry that needs to get added to the Dops sim on that frame.

2) In Dops point an RBD Fractured Object at that Sop, and use an expression in the "Creation Frame" parameter to set it to the current frame if any geometry exists in your Sop.

3) With setups like this where new stuff gets added to the sim as it runs I usually find it easiest to bring the geometry from Dops back in to sops using the "Fetch Geometry from DOP Network" option on an Dop Import Sop, instead of the default "Transform Input Groups"

This is very similar to how Houdini's pyro clustering creates multiple Smoke objects.

[Ryan]

Check out what I've been doing. Just started your scene from scratch and playing around. I'm getting new pieces back in OK.

Most of the work is some tricks in SOPs.

WindowScatterByImageGrowing_RYAN.hipnc

Edited May 15, 2013 by Ryan