rigid body collision and using goals to 'shape' the position of fragments

[anthonymcgrath]

hi guys i'm having a bit of an issue here - i've got a rbd sim using bullet and a glue constraint.  Basically a bullet passing through an hour glass...


overall its working really nicely and sims nice and fast.  However theres some chunks that sit on top of the larger unbroken piece at the bottom.  I cant suss out how to refine the collision of this shape sadly

so what i want to know is if its possible to use a goal for the simulation - i'm fairly sure i've seen this done many moons ago... I want to be able to take the pieces on top of the unbroken chunk and sort of force them and move them out of the way... so the simulation tries to work towards a final resting position?  I hope i'm making sense here?

ta
ant


 

[Yon]

Hmm I have some ideas..

-Take your centroids(points used to fracture). Point VOP - P into V.You can also put P into vector to float, and multiply each component by a constant to control direction, then vector to float , into V. Plug into N to visualize. This will be the initial velocity. Attrib transfer this V into your geo before DOP.  You may have to enable use point velocity on rbdpackedobject in DOP (can't remember). This will definitely move those pieces but your whole sim at the same time unless you figure out how to isolate the centroids of the pieces you want to move. If this makes your pieces break before the bullet, make a active attribute on the bullet and set value to 1. Attribute transfer active into hourglass in SOP solver in DOP.

 

- As for the interpolating to a rest position, maybe isolating the problem pieces in a SOP solver in DOP and key frame a transform.