Hi there,

out of boredom I opened one of my older files, just playing with the multi pin constraint workflow. I got that from an old example file from the Houdini Help (apply data or maybe multipin constraint), but if I want to open those example files now, Houdini crashes.
Anyway, something seems to have changed in Houdini 11 (the file worked fine in 10) and the spheres in my scenefile get some weird velocity, the only force that should be influencing the spheres is gravity.

Can somebody please open up my scene to check out if there's missing something or if the workflow has changed ?

Thanks,

Manu

hm I fixed my problem, but I'm not too happy with the solution I came up with.

In the constrained location of the RBD Pin Constrained I'm now using a point expression to access a center attribute I created in SOPs:

point(“.:mygroup_” + ($OBJID-2) + “/Geometry”, 0, “center”, 0)

Unfortunately that only works if you know about every single dopobject in your scene, you got to count the objids to be able to know which number to subtract.
Instead of using ($OBJID-2) I was trying to use a stamp expression which should fetch the correct ID from the apply relationship DOP but it doesn't work, something get's screwed up if I use this expression:

point(“.:mygroup_” + stamp(“../applyrel1”, “AFFECTEDID”, -1) + “/Geometry”, 0, “center”, 0)

Does anybody know why this is not working?

thanks,

Manu

figured it out with querying the Objid from the frist “mygroup_” Object with Python and subtracting that value from each ID.
I used Python because I'm not sure how to get an objects ID with hscript expression, is there a way to access the “Options” field with dopoption() ?

Anyways, I attached my solution for anyone who's interested!

thanks,

Manu

Thanks a lot, dude! hard to figure this one out without any examples. documentation is really lacking!

Cheers