glue strength control by colour doesnt seem to work?

[anthonymcgrath]

hey guys i'm back with more questions. 

so i did some googling, checked out some scenes and read a few threads and i think i have an idea of how to control the glue strength in my network... so i've applied colour.. used it to fracture the object and now i want that to control glue strength.

i want to get it so the red areas break easily and the black is much harder to break - but i've been fiddling with numerous ways to do it and i cant seem to get it working   in my scene (attached) i have applied colour which breaks it in the red areas and i'm using that in an attribute create to try and multiply glue strength.  But its like it has no effect. 

1.20am over here in uk so i may have it all wrong or missed something - can anyone take a quick look and see what clanger i've dropped please?

thanks!

ant

glass_ball.hip

[Sepu]

Hey Anthony 

Here is a working version, you need to play with attribute transfer and also with the settings on the Attribute wrangle for the strength then in SOP Solver inside DOP I have the same delete but I just use an expression that you can also play with it.

I clean up you network a bit.

glass_ball_v001.hipnc

[anthonymcgrath]

@Seputhank you I will take a look at that scene shortly and see what you did differently. I didn't think I would need a solver because the object didn't need the strength value adding each frame.. or at least to my mind heh!  That gif looks like it's doing exactly what I wanted it to

 

So generally speaking do you always  need to use a sop solver in dops to transfer changing values such as this to simulated elements in houdini? It seems to be the case with most scenes I've dissected?

[Sepu]

This is one way to do it, as you know in Houdini there is many ways to do the same thing.

The Solver is just deleting part of the connectadjacentpieces (Cd.r) not transferring the strength, in this case. Also in the Wrangle you do not need the "if statement" I forgot to delete it when testing.

Mainly the main things are Strenght attrbute in the Wrangler which is a multiplier with the one on the Constraint network (Dops), the transfer attribute and then the expression of the SOP solver. But yes the Sop solver can do that as well, accumulated values, etc.   

[anthonymcgrath]

@Sepu so in various scenes I've come across now the sop solver is used to accum values. However I wasn't able to get it to decrease them.in a simple scene i had a fem object and it fell to the floor in a squishy heap. I had a second object that passed colour to the fem thing and this was shapestiffness. It was done using attr transfer in a sop solver. So when the object intersected it caused the fem thing to stiffen up and inflate. But when it moved away I wanted the fem thing to deflate again and for some reason it wouldn't do that. Can a sop solver do this sort of adding them removing of a value?

 

Thanks again for your help that scene file was great

 

[anthonymcgrath]

To add to this problem I'm guessing I may need to use a wrangle that tells the shape to be super squishy  (low stiffness) ..causing it to fall to the floor in a heap.. but if a red colour enters the shape (by way of intersecting geo) then the shape stiffens up.  The thing is I don't know if this would need doing in a sop solver or if it can be done outside.  I guess the end goal is to be able to use an object that if it contacts the mesh stiffens it up.. but if it moves away the fem shape falls to the floor again.  Bit puzzled on this one.