im trying to do a grain sim and i wish to get s much stronger clumping effect (much larger chunks, less breakable.)

ive used a procedural noise to define chunks in a group, and am applying the attractionweight attribute only to those points.

i get the effect im after by cranking the weight up to 10 or so, but obviously this causes quite bad instability since the weight should be 1 or below. - i get chunks jumping around when they fall.

that leaves me with stiffness. does not seem to be exactly the right parameter to play with, but anyway, cranking it up to a high value ( i think, no idea what is a sensible range) of 500,

causes the grains to collapse when hit by a collision object ( i can see them sinking down in the area where the collision object is rising from below. -obviously they should not do this)


ive searched around but i cannot see any detailed information about controlling clumping beyond the basic “wet sand” effect.

so

a) any way to get a high weight value stable?
b) any other method to get larger clumps?


- ive played around with explicit constraints, but they are slow and use loads of ram, i never got far enough to get a decent result.

i'm looking for the same answer actually, did you find a solution ?

It seems that as you said, the weight above 1 causes instability, and same for the stiffness above 100, apparently.

Still trying to fix this !