Page 1 of 1

UV channel bug

Posted: Tue Feb 23, 2021 7:36 pm
by v-cube
Hi Paul,

Here is something I wanted to show you for a long time:
walth-23-02-2021-decalbug.mp4
(15.4 MiB) Downloaded 3413 times
as it seems octane does not respect mapping channels other than 1...

here is the scene and the mappings:
UV-Decal-Test.zip
(217.84 KiB) Downloaded 224 times
If you have any questions about this I would be happy to help.

best

Andreas

Re: UV channel bug

Posted: Tue Feb 23, 2021 11:51 pm
by face_off
Hi Andreas - thank you for the incredibly clear video showing the issue!

Firstly, the Rhino renderer is not rendering this scene as you are wanting, so I think something is not right with it.

Secondly, Rhino will provide ONE set of UV's for the mesh (regardless of the "Multiple Mapping Channels" checkbox state). So the Octane "UV Set" parameters is effectively always using Set 1. I has asked the question of McNeel if it is possible to get multiple UV sets at https://discourse.mcneel.com/t/multiple ... els/119120.

To render a decal, you would either need to a) have a separate mesh object with the Decal image map applied to it's material, or b) use the Composite material as you have done and set the decal position with the material mask transform (as you show in the video).

I hope that helps.

Paul

Re: UV channel bug

Posted: Wed Feb 24, 2021 12:23 am
by v-cube
thanks for looking into this,
Firstly, the Rhino renderer is not rendering this scene as you are wanting, so I think something is not right with it.
I am not quite sure what you mean...

If I set up a Rhino material, I can apply the different mapping channels to the texture and it will display / render accordingly:
Decal-03.png
Decal-02.png
...Or did I misunderstand you?

Re: UV channel bug

Posted: Wed Feb 24, 2021 12:37 am
by face_off
If I set up a Rhino material, I can apply the different mapping channels to the texture and it will display / render accordingly:
Your scene as downloaded did not render that way, so I thought something wrong :-) Regardless, the other comments still apply.

Thanks

Paul

Re: UV channel bug

Posted: Wed Mar 31, 2021 1:40 am
by face_off
Hi Andreas

I have done some work on this issue. I posed the question of how to implement this to McNeel. You can see their response here -> https://discourse.mcneel.com/t/multiple ... els/119120

The approach that McNeel recommend sounds viable, although it doesn't sound like anyone has actually implemented it yet, so they may be issues.

Also, each mesh in the scene would need to be processed for each UV channel, so loading in to Octane would be slowed as each mesh with more than one channel would need to be processed multiple times (unsure how much).

So in summary, this may be possible but would require some work, and may slow down scene loaded. If resolving this issue is a high priority to you, and can put some more time in to it, but if it's low priority, I suggest parking the issue. Let me know.

Thanks

Paul

Re: UV channel bug

Posted: Sat Apr 03, 2021 5:53 pm
by v-cube
If resolving this issue is a high priority to you, and can put some more time in to it, but if it's low priority, I suggest parking the issue. Let me know.
sigh...

It is not really a high priority, but just something I would simply expect to work... multi channel mapping is not something exotic IMHO...

best

Andreas