Cloth tearing in Houdini 16

   7628   8   3
User Avatar
Member
31 posts
Joined: Feb. 2017
Offline
Hi,

Are there any examples of how cloth tearing and fracturing work in Houdini 16? When clicking on “Enable Tearing” on the cloth solver and “Enable Fracturing” on the cloth object, my cloth with teach all of its polygons individually apart.

From what I understand, I should be able to affect this by adding a fractureapart attribute however this doesn't seem to affect anything.

Also, the docs don't actually make any reference to the Fracturing tab on the Cloth Object.

Does anyone have any ideas?

I've attached a simple example file of where I was able to get to.

Thanks
Edited by ajk48n - March 30, 2017 12:38:47

Attachments:
Basic_Cloth_Tearing.hipnc (201.4 KB)

User Avatar
Staff
429 posts
Joined: June 2007
Offline
An important fracturing bug was fixed in 16.0.562, so be sure to get this version of Houdini 16, or newer.

For the rest, it's just a matter of playing with the Fracture Threshold parameter on the Cloth Object to get the desired behavior. I'd go up to, say 10000 in this example.

About the fracturepart attribute, make sure it's called “fracturepart” and make it a primitive attribute.
Alternatively, you can simply make use of the Solid Fracture tool, which was designed to work for the Solid Object but also happens to work for the Cloth Object.

I'm attaching a version of your file in which I made these changes.

Attachments:
Basic_Cloth_Tearing_Fixed.hipnc (242.1 KB)

User Avatar
Member
31 posts
Joined: Feb. 2017
Offline
Thanks for the quick reply and the sample file.

I'd like to confirm one other thing though. The solid fracture tool does not work on a grid, is that correct?
User Avatar
Member
8 posts
Joined: June 2014
Offline
where to download 16.0.562 , its 16.0.557 in sideFx.
User Avatar
Member
7708 posts
Joined: July 2005
Online
First ensure that you're logged into this website. Then from the download page, scroll to the bottom and click on “Daily Builds”. Download the latest 16.0.XYZ build.
User Avatar
Member
24 posts
Joined: March 2014
Offline
Not to hijack this thread but I took the provided scene file to try and learn more about creating tearing cloth. I added a group of points down the center of the grid and wondered if there's a way to tell it to tear the cloth on the points in the group? Thanks.

Attachments:
tear-test.hipnc (286.6 KB)

User Avatar
Member
12 posts
Joined: Aug. 2013
Offline
gswartz, I think the way to do this is to set fracturepart attribute for the prims on either side of the line you've created in points. Looking at the Solid Fracture attributes it is working with prims not points.

I've attached a hip that explicitly sets fracturepart for a group of primitives but I can't work out how to set the tear threshold or interoperate with solid fracture. I think the idea is that you can modify the solid fracture DA yourself but I haven't delved that far yet.

All, is there a tear threshold attribute you can set per prim?

Attachments:
Basic_Cloth_Tearing_SelectedPrims.hipnc (339.4 KB)

User Avatar
Staff
429 posts
Joined: June 2007
Offline
The cloth solver recognizes a point attribute called “fracturethreshold”. This works as a multiplier for the Fracture Threshold parameter on the Cloth Object.
User Avatar
Member
1 posts
Joined: June 2014
Offline
thanks!!!!
  • Quick Links