I guess that the Glue object increases it's “glue strength” with more objects, but is there a way to work with this value having few pieces todo fast simulations and then increase the amount of fractured pieces without having to “tweak” the internal glue value to achive the same look as with few pieces ?

Also are the “Glue Strength” / “Glue Impulse” values animatable? because I tried to key them up but when I drastically decrease the Glue Strength value in the middle of the simulation, everything doesnt fall aparat as I anticipated.

/M

the internal glue strength should be the force needed to break the connection between each fragment and null object to which they are internally glued to. So you should not get so much different behaviour with many pieces than with few pieces as long as the the mass of the whole glued object is the same, it off course depends on many factors, you cannot expect it behave exactly the same.

to animate glue strength you need to dive into the rbd glue object.
First make it editable by rightClick and Allow Editing of Contents
then dive into it
inside you can see rbd fractured object, make it editable too
dive into it
there select rbd state node
under Glue tab you can see the listbox next to the glue strength parameter
change it from Use Default To Set Allways
now return back to your DOP network and your animation on internal glue will be working

Oh thanks! I see now, awesome way to work !

My little simulation looks so much cooler with animated Glue

/M

I'd just like to continue on the same subject with a new question about glue

Could I drive the glue value with something like a radial falloff from a given point ?
Essentially what I want is for my object to have higher glue value further into my shatter geometry.

/M

look at the choreographed breakup in the help examples
there is an expression in the rbdstate1/Glue Strength parameter
this is simply comparing $tx (position x value of each piece) with position x sweep plane which is just a helper object

you can do what you want the same way (with different expression of course)

Ah ! i was looking at that example some days ago for another reason, didnt make the connection that it could be used for this to, thanks !

/M