H16 - Fractures falling into a flip tank - Explodes

[Arun]

I'm learning Houdini, and am trying to do a bullet-solver RBD Fracture, with glue constraint, falling into a FLIP tank. RBD PackedObject works fine with the constraint & collides perfectly with groundplane. But when I make them fall into a flip tank, the pieces explode at the frame where they touch the water. Feedback scale is set to 1.

Tried a default RBD sphere with Flip, and though I can control the Flip interaction with the "Physical" tab, the Sphere bounces still as if on hard ground.

Can somebody help me with this? [ Attached a sample fileRBDFlip001.hipnc]

[Atom]

I couldn't configure your scene, I think the glue portion is messing everything up. I threw away all the nodes except your original cube fracture. I recreated the scene using the shelf tools. I basically got the same result, everything explodes.

So the cube is too heavy.

I turn off the Compute Mass on the RBD Fracture object and set the weight of the cube directly to a mass of 10 (try lower values as well). This helps makes the cube lighter. I turned on Allow Fracture From Feedback under the Fracture tab of the Rigid Body solver. The fracture stays together until impact then it falls apart. No glue needed. I have animated the Feedback Scale from 2 to 0 over 12 frames. This is timed with the initial impact of the cube with the fluid. The feedback scale of 2 makes the surface of the fluid much like a groundplane. Then as it animates down to 0, over time, the fracture pieces that are skating on top slowly sink down into the fluid.

 

 

ap_RBDFlip001.hipnc

Edited January 21, 2018 by Atom

[Arun]

Thanks for looking into it, Atom. Will see if I can improve that to a natural-looking interaction

[nAgApAvAn]

 this might helpful to start from more details in the vimeo description