Forums Technical Discussion COPs flow across UV islands

COPs flow across UV islands

   627   5   1
User Avatar
frxnlab
Member
4 posts
Joined: Feb. 2017
Offline
 
Hi all,

Just started learning COPs and already my brain has been broken. I'm hoping someone can perhaps point me in the right direction.

(I've uploaded ref images in the hopes it helps to makes sense of my question)

Basically I tried to experiment with a flow texture on piece of geometry. I wanted to find the starting positions by baking it from a reference geo. I then fed it into a flow block but then quickly realized it wasn't going to be flowing across UV island borders in a similar way to Substance Painter.

Is there a way to achieve this flow that I am unaware of? I Googled as much as I could but didn't find an answer.
Edited by frxnlab - Sept. 17, 2025 02:48:38

Attachments:
Flow_04.png (635.5 KB)
Flow_01.png (249.3 KB)
Flow_02.png (35.9 KB)
Flow_03.png (429.7 KB)

 Report
User Avatar
Konstantin Magnus
Member
717 posts
Joined: Sept. 2013
Offline
 
I don't think there is a built-in node for this yet but Mattias Malmer created a setup for UV adjacency:

https://github.com/3Dmattias/Houdini_Escapades/tree/56b96a34d856d56c8d344e2cba7e24c18290222e/hip [github.com]
https://procegen.konstantinmagnus.de/ [procegen.konstantinmagnus.de]
 Report
User Avatar
GrahamDClark
Member
283 posts
Joined: July 2005
Offline
 
As well as Mattias Malmer's solutions have a look at Yancy Lindquist's https://vimeo.com/yancyquist [vimeo.com]
Yay! I'm certified! https://media.sidefx.com/uploads/accounts/badges/certified_instructor_badge_AkLiM3h.svg [media.sidefx.com]
 Report
User Avatar
Konstantin Magnus
Member
717 posts
Joined: Sept. 2013
Offline
 
To let textures flow across UV islands, we could also pre-store offset sampling positions on a separate map to be picked up by a streaking solver.

https://procegen.konstantinmagnus.de/flowing-textures-across-uv-boundaries [procegen.konstantinmagnus.de]


Edited by Konstantin Magnus - yesterday 04:10:40

Attachments:
tex_flow_cops.jpg (92.0 KB)
tex_flow_across_UVs.hip (311.1 KB)
tex_flow_title_02_small.jpg (35.5 KB)

https://procegen.konstantinmagnus.de/ [procegen.konstantinmagnus.de]
 Report
User Avatar
Konstantin Magnus
Member
717 posts
Joined: Sept. 2013
Offline
 
I have added a COPs only version.

Is there a COP node that can replace xyzdist + primuv so we can get rid of the wrangle?
Edited by Konstantin Magnus - yesterday 16:34:45

Attachments:
cops_tex_streak.hip (335.3 KB)

https://procegen.konstantinmagnus.de/ [procegen.konstantinmagnus.de]
 Report
User Avatar
tamte
Member
9265 posts
Joined: July 2007
Offline
 
Konstantin Magnus
Is there a COP node that can replace xyzdist + primuv so we can get rid of the wrangle?
in your case when taking small steps you can probably replace it with Raytrace COP, use your offset P as origins, rasterized N as directions and sample the "uv" attribute (as RGB then convert to UV )
Tomas Slancik
CG Supervisor
Framestore, NY
 Report
  • Quick Links