Cloth (Paper-like sim) Tear Mapping

[zeekindustries]

Hello!!!

I'm kinda new to Houdini and I'm working with cloth simulations, I would like to make a tearing paper simulation using the cloth solver and wanted to have the areas where it can be torn be driven by a color channel of a texture, say, the red channel for example. I tried creating an AttributeCreate followed by a AttribFromMap but this doesn't seem to do the trick. I'm attaching the files that I'm currently using if someone can point me in the right direction in order to achieve this.

Thanks a lot to everyone whoever gets to read this, any help would be very much appreciated!!!

clothSimTest_05.hip

[kleer001]

There's a CMIvfx tutorial exactly on that. (With requisite unnecessary dance song.)

http://www.sidefx.com/index.php?option=com_content&task=view&id=2497&Itemid=132

[kleer001]

The expression you want is 'tex' or 'pic'. You'll be using that to color your points with an attribCreate SOP. With a 1:1 ratio of points to pixels you should get your exact image.

Edited September 4, 2013 by kleer001

[zeekindustries]

So the plane rows and columns should be the same size as the pixel size of the image? The expression goes on what kind of node, a point Wrangle? Sorry if that sounds like stupid questions but I'm still pretty new to Houdini, Thanks you very much for all the help!!!

[kleer001]

No need to apologize, we're all learning here. (Except for OldSchool, he's the final boss)

You don't have to have the same size in your grid as your image, but that will guarantee a 1:1 correspondence between the two. If you want to go crazy you can even have a higher resolution in your geo than your image.

You can apply the color from the image to the geo with a point SOP or an addAttribute SOP (or a VOP SOP or a point Wrangle, or any other way you want). But before you do that you need to apply UVs to your object. Use a uvtexture SOP for that or a UVProject.

In a textport pane type 'exhelp tex' and you'll get the parameters and you can get going.