Jump to content

Emit Debris from dynamically fractured objects

Recommended Posts

Hello all,

I am quite new with Houdini, just started in the beginning of this month. I enjoy Houdini very much, however, I encounter a problem here and have been here for quite some time.

So what I want to do it basically make a scene of a ball crashing a wall and then have debris coming out of the wall as the effect of the crashing and the wall being torn down. Well basically want to get this to the next level.

However, I have been looking for a way to do this and found somethings but maybe because I still need to learn more about Houdini, I do not really get how to do this properly. :(

So I thought I can start from a simpler scene first.

Firstly I read a post hereand have tried to do it step by step and even try to mimic the scene exactly but I still have no luck. I use Houdini 12 so I grabbed the torus_debris_h12_fix.hip file.

I did everything as exactly as how it is in the file, but as from what I check, I see that the "delete" from the particle_location1 does not work properly (If what I see is correct). Although I see this problem, I have no idea how to fix it since I think all is correct :wacko: I attached my file here.

can anyone help me on this? and maybe if you know a tutorial that can be helpful for me to get the hang of this?

Thanks in advance


Edited by Marc

Share this post

Link to post
Share on other sites


the problem ist that the RigidBodySolver, does not creat the "creationtime" Attribute properly.

If you check it in the DetailsView you'll see that its set to 0 on every primitive.

cheers Martin

Share this post

Link to post
Share on other sites

Hi Martin,

So I have been trying out stuff and now I think I am close to make it work. I activate the create group deep inside the RBD Solver node and it almost work I think, now the creation time are not 0 anymore.However, right now the only problem is that it works until the "emit" attribute in particle_location1 after that, popnet1 does not work so no particles yet. Any idea?

Thank you :)

I attached the newest version--


Edited by mo22

Share this post

Link to post
Share on other sites

yes, I have looked at this one http://forums.odforc...re-not-working/ but can't really find how to relate it to mine because I am not using the debris from the shelf.. Can you tell me what you did on the file there? when I opened it I got some errors in voronoifracture..

thank you :)

Share this post

Link to post
Share on other sites
Can you tell me what you did on the file there?

1)Create simple obj and fracture it using voronoi fracture sop. Convert it rbd fractured obj or rbd glue obj.

2)Select this obj and use debris shelf tool.

3)You will notice that it adds debris obj at scene level.

4)Jump in obj debris, in to popnet. It is not working for two reasons .

First It doesnt get the geometry to generate particles from. It is referring sop solver in dop for this geo. That sop solver is referring debris / debris_geometry_setup. If you jump in debris_geometry_setup you will see delete_original sop complaining there is no inside group.

To get inside group as suggested by Beny in the post you refereed first, do the following

go to /obj/AutoDopNetwork/rigidbodysolver1/voronoifracturesolver1/fracture_SOP_solver/voronoifracture

(double click on fracture_SOP_solver to jump in then go to voronoifracture.)

and turn on create output group


Source node shows few warnings in impulse birthrate parameter.

It has few expressions, accessing few parameters on debris obj but as mentioned in the post there are few problems

Its a faulty expression.

There is no parameter called birthrate(ch("/obj/debris1/birthrate")) on debris object but its only called rate and there is nothing called constant - ch("/obj/debris1/constant") so impulse birth rate becomes zero therefore no debris

So the simple option is to delete this expression and write some number. It should work now.

Share this post

Link to post
Share on other sites

Yes, using the debris tool is working now :) thank you!

I also got the original file working for me now, maybe to help someone, what went wrong is that I do not have source in the popnet, so it gave an error and did not emit the debris. if you put the source in it, it should be working :D cheers!

Share this post

Link to post
Share on other sites

Can anyone help?


I can't seem to find this expression inside the vroinoi fracture inside the RBD solver so I can't seem to fix the problem of the debris.

Share this post

Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now