Say you have a sphere, using voronoi fracture, or mograph fracture object or cloner, you want this sphere to roll around as one object, say it rolls off the edge of a table or is thrown at something, is there any practical way to make it break apart so the segments inherit the force of the larger object they were making up?
My best attempt so far was to set the dynamics tag individual elements to off, then in xpresso, use the dynamics body state object to get the torque of the generator, compare torque to threshold, feed that into flip flop node, feed that into the dynamics tag individual elements parameter, so it gets set to “all” and stays that way after torque threshold has been reached.
This works, in the sense that it does break after threshold breach, but the segments do not inherit the prior motion of the object (or at least, they do it too late, after the collision) so they break apart extremely unrealistically.
https://www.dropbox.com/s/bw1ctmxqdxle7pg/fractureDebug.c4d?dl=0
Using the collision node rather than threshold via the dynamics body state object seems to work a little better..
It seems that both approaches fail practically because the collision trigger or velocity is registered on the frame after it occurs, for an accurate breakup it would need to trigger at least one “frame”/unit of time prior to the detected collision, or more practically, the inherited velocity of the fragments/clones should be taken from a point in time prior collision.
In certain situations, for example when an object is falling straight to the floor, this delay is irrelevant, but if you are colliding with curved surfaces, pointy/thin objects etc, the issue becomes obvious.