switching to glue

[logix1390]

Hello,

I am trying to switch from a Hard constraint to a Glue constraint which I have successfully done.

However I am trying to switch to the glue constraint only for the pieces that are broken.

I know bullet automatically  creates a broken group so I am using this information in a sop solver like this:

if(s@constraint_name=="Hard"){
    if(f@force>400 || f@angle>.1){
    i@group_broken=1;
}}

else{
i@group_broken=0;
}

Then in another primitive wrangle:

if(@Frame>31){

    s@constraint_name="glue";
    s@constraint_type="all";
    f@strength*=-1;
}

 

 

Now this actually works ... however the glue constraint is rebuilding and connecting back to the unbroken group which means it is freezing in mid air ( I am aware i set my strength to -1).

How can I tell it to only rebuild the glue constraint only in the broken group and not connect anything back to the unbroken group.

The goal is to break the wall and maintain a large dent as it breaks.

 

I have been trying to figure out a solution for a few days now..any help would be greatly appreciated.I will attach my scene file for anyone that wants to take a look.

Thank you

switch_to_glue_from_broken.hipnc

[vicvvsh]

I think you need to look up this topic https://forums.odforce.net/topic/20691-realistic-dynamic-fracturing-with-bullet/

[logix1390]

Hi Viktor.

I went through that thread a few times and all the scene files. I am not trying to do anything overly sophisticated or advanced like what they are doing, I just need to know how I can rebuild the glue constraint network only in the broken group without it connected back to my static unbroken group. I was trying to work with the "@next_constraint_name" attribute that bullet recognizes but i havn't had any luck with that either...

would love to get any tips. 

[Noobini]

not sure what you're trying to do with -ve strength: (it's unbreakable)

I would go for strength = 0

EDIT: ah ok, maybe it's to do with you wanting to retain the 'large dents'...my bad.

Edited August 13, 2018 by Noobini

[logix1390]

Hey Noobini,

I am trying to achieve  bending/ large denting to my wall while staying dented as it falls to the ground...

So the -1 strength is so that the wall deforms by the hard constraint and then stays deformed after a certain condition

in this case , if Frame>31 then switch to Glue with negative value. (Should be a frame  26 actually)

If I set my strength to 0 then the glue will eventually break and not hold my deformation.

It is working fine...The only problem is that I only want the glue constraint to rebuild on the part that is broken (top half of the wall) and not the static part.

Even if I set the wrangle to the broken group , it will not work. 
 

 

[vicvvsh]

Hi Mike,

if rebuild constraints from broken group they connect the same pieces again and this behavior is currently in your simulation. I clearly don't understand what you want to achieve therefore I made two wrangle in sop solver DOP. Take a look, maybe it is what are you looking for.

switch_to_glue_from_broken_01.hipnc