Jump to content
Ankit Pruthi

Constraint woes - pinning two different packed objects together

Recommended Posts

Alright so i have been through plenty of posts on using constraint networks in case of packed RBD objects, but i still can't quite find a way to achieve this simple task -

 

Two packed rbd objects (pre-fractured) - one has animation and is set to be a deforming static object, and the other is an active object. I need to pin few of the pieces of the active object to the deforming one.

 

Glue and hard constraints work well for scenarios where the static object isn't deforming. But on deforming geometry, the objects stay constrained to their location and do not move with the animated points.

 

I've also tried cone constraint which seems to make the active object follow the animation but is somewhat unstable, the pieces try to stick but wobble all the way. Not sure what would be the correct way to do this.

Any insights on this if any of you guys have tried would be of great help!!

GluePinTest.hipnc

Edited by Ankit Pruthi

Share this post


Link to post
Share on other sites

I was going to send RFE about this, but found another issue with custom center of mass recomputation, and just forgot..

Right now what you can do is to recompute position and orientation (@P and r/orient attributes) of constraint points which should be connected to deforming state pieces.

Share this post


Link to post
Share on other sites

Right now what you can do is to recompute position and orientation (@P and r/orient attributes) of constraint points which should be connected to deforming state pieces.

I'm not very expirienced in DOPs so I'm wondering how to go about this. Would it work if I transform that constraint points in SOPs and bring animated/deformed constraints into DOPs (not sure if it's possible), or it should be done in DOPs somehow with SOP Solver maybe (object merging deformed pieces and transforming positions of constraint points with that)?

 

Thanks in advance for any tips.

Share this post


Link to post
Share on other sites

Here you go!

Keep in mind that this setup will work only if your hard constraint type is "position". To make it work for both pos and rotation you have to compute matrix for each static object and transfer rotation to constraint points.

GluePinTest_FIX.hipnc

  • Like 7

Share this post


Link to post
Share on other sites

Thanks for the example Pavel!! This does exactly what i was looking for!

 

Houdini really does need a more straightforward way of doing this however.

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

×