Wood RBD Sim Unstable with Constraints

[TheDude123]

Hi,

I've got a "wood" structure that needs destroying and I'm getting stuck on the simulation part. The sim looks good for about 3-4 seconds and then the fractured pieces start to move of their own accord (i.e they freak out).

I've fiddled with substeps (both DOPNET and bulletrbdsolver), collision geo, constraint iterations, etc. I watched countless tutorials and searched the web looking for answers, but nothing seems to work.

I just don't know where the issue is coming from.

Any help or guidance would be greatly appreciated. A link to video showing problem.

https://www.dropbox.com/s/ok51dj13f5187gf/Sim_Issue_A.mp4?dl=0

Thanks!

 

Edited October 16, 2022 by TheDude123

[Benyee]

nice setup for wood fracture

I did some optimizations for your scene,see the marked nodes

for the rbdcluster node,you should check off the "fuse clustered pieces" since you have to make collision shape of each piece separately in dop,and so you should keep the original "name" attrib after clustering

for the constraints,I split the "glue" constraint into 2,one is cluster inner glue(glue constraint) and the other is glue between clusters(hard constraint,to make the entire wood structure a little bit softer)

and other modifications,for the bullet solver and setup for wood mass,etc,hope it helps

Wood_RnD_Example_File_v2.hip

 

 

[TheDude123]

On 9/23/2022 at 7:38 PM, Benyee said:

nice setup for wood fracture

I did some optimizations for your scene,see the marked nodes

for the rbdcluster node,you should check off the "fuse clustered pieces" since you have to make collision shape of each piece separately in dop,and so you should keep the original "name" attrib after clustering

for the constraints,I split the "glue" constraint into 2,one is cluster inner glue(glue constraint) and the other is glue between clusters(hard constraint,to make the entire wood structure a little bit softer)

and other modifications,for the bullet solver and setup for wood mass,etc,hope it helps

Wood_RnD_Example_File_v2.hip

 

 

Hi Benyee,

Thanks so much for taking a look. I went through your scene and cached it out, but it looks like the problem I'm having is still there (the pieces start to float around and have a life of their own after some time).

Again, thanks for trying.

[islamoos]

On 9/28/2022 at 8:40 PM, TheDude123 said:

Hi Benyee,

Thanks so much for taking a look. I went through your scene and cached it out, but it looks like the problem I'm having is still there (the pieces start to float around and have a life of their own after some time).

Again, thanks for trying.

Sounds like your problem is not having the correct name attribute on your pieces.
For instance if you have two fractured objects each containing 10 pieces, you have to make sure when you assemble to change the 'piece' prefix to the name attribute to something custom. Otherwise you have two pieces with the same name and the solver doesn't know how to evaluate them.
Cheers

Edited January 24 by islamoos