Sops to cops

   6152   9   4
User Avatar
Member
253 posts
Joined: July 2006
Offline
Coming from this one https://www.sidefx.com/forum/topic/51410/ [www.sidefx.com] so I don't hijack my own thread.

I got lucky because I could get the world position from the uvs. In the case of an arbitrary mesh I'd make a grid if points in world space that represent the pixels, do the tricks in sops and then bring the colors to cops.

Attachments:
sopcops.hipnc (202.5 KB)
ezgif-4-3fdd96eccf.gif (2.3 MB)

User Avatar
Member
280 posts
Joined:
Offline
excellent example!!!!
thank you for this

best regards
Patar
Edited by patar - Aug. 27, 2017 05:01:05
User Avatar
Member
253 posts
Joined: July 2006
Offline
Thanks! You're welcome
User Avatar
Member
603 posts
Joined: July 2013
Offline
Thanks for taking the time to do that example. I hope you agree that there are some Houdini improvements that would make this ‘type’ of effect easier.

#1 - COP Wrangle node with OCIO VEX functions
#2 - SOP Import Grid Points node (to ensure a 2d plane of points)
Houdini Indie
Karma/Redshift 3D
User Avatar
Member
253 posts
Joined: July 2006
Offline
OCIO Vex funtions, I'm sure that'd be cool, although for this specific example I don't imagine how they could be helpful, it might be because I haven't had the time or need to get around all the OCIO business.

#2. I'm not sure how that node would work. Look at the cop globals, we need a logic to import data. The most useful are the X and Y positions, analogous to u and v or s and t. So we need to find a correlation between that and world ( object ) space. So what I've done a couple of times before is transform the mesh to uv space and sample attributes from that geometry ( forget the pixel grid I talked about, I got confused with a related experiment ). Of course it needs to have properly laid out uvs.

I'm sorry I couldn't agree more, I'm just trying to be sincere AND constructive at the same time.

Toodles!!!
User Avatar
Member
7755 posts
Joined: Sept. 2011
Offline
The copnet sop does create a mesh with color from the image.
User Avatar
Member
253 posts
Joined: July 2006
Offline
jsmack
The copnet sop does create a mesh with color from the image.
I'm sure you misinterpreted. If not, maybe a hip file ?
User Avatar
Member
8 posts
Joined: Dec. 2013
Offline
Hey, this example works great if the grid only has 1 primitive because you're specifying prim 0 in cops. I can't wrap my head around how to make this work for a more complex geometry with multiple primitives. Any idea?
User Avatar
Member
253 posts
Joined: July 2006
Offline
Colby Winfield
Hey, this example works great if the grid only has 1 primitive because you're specifying prim 0 in cops. I can't wrap my head around how to make this work for a more complex geometry with multiple primitives. Any idea?
I just noticed your post … Check updated scene.

Attachments:
sopcops_v02.hipnc (265.9 KB)

User Avatar
Member
385 posts
Joined: July 2018
Offline
thanks for sharing!i am looking for something similar but much simpler.
i just have a circle resampled with point color and i want to bring that into cops for processing.

The Geometry node just brings the projected circle white without any color information which is a bummer
  • Quick Links