vellum Vellum - Different Rest Lengths control in one Cloth

[Nikoletta]

Hello ! I am very new to Houdini and I am looking to assign different Rest length values on a cloth, similar to this example https://vimeo.com/369271677. However, so far my cloth gets distorted and triangulated. Could you please point me to the right direction ? ( i can also add my failed attempt if that helps) . Your help is much appreciated!

[underscoreus]

Heyo, had a look and came up with the setup below. Still some improvements that could be made, like having the shrinking of each constraint happen over the course of a few frames instead of instantly to get a smoother transition etc. One of the key nodes when working with vellum and wanting to really art direct your cloth like this is the "vellum constraint property" node. As long as you have that and either an initial group or use the vexpression tab to fetch attributes or groups from sops then you can do A LOT of stuff with Vellum.
The setup below mainly works by creating an animated group in sops to control a rest length multiplier attribute on the vellum constraints. This is done by using a solver sop and merging the current frames group with the previous frames group and then adding to it, causing the group to grow over time. Then setting a rest length multiplier attribute, "rest_mult", based on the animated group. If you are in the group, have a lower rest length multiplier, if not, just be normal and have a value of 1. Then lastly using the vexpression in the "vellum constraint property" node to get this animated attribute from SOPS and bring it into DOPS to have it multiply with our rest length scale.

Hope that can be of help!

animated_restlength_mnb.hiplc

[Nikoletta]

This is fantastic!!! Can’t thank you enough for the file and the explanation. I will give it a go now