Hi guys,
quick question: it seems that I don't understand how the "UV display" section in the display options is supposed to work.

Naively, I would have assumed I could specify the name of any float3 attribute under “UV Attribute” and it would then visualize the values from that attribute in the UV View for me.

However, if I enter an attribute name there, in most cases after I press Enter, "uv" is simply set again. (The field value doesn't change). The behaviour seems somehow be related to what is currently selected..

Example:

• The default attribute name is “uv”. But I have three uv sets (uv, uv1, uv2) in a geometry network.
  I want to display "uv2", so I replace "uv" with "uv2", press Enter, and it instantly makes it "uv" again
  
• It seems like if I delete the "uv" attribute, it lets me enter "uv2"
  
• But then it changes this back to "uv2" if I try to enter "uv3"
  

I haven't used the function much yet, so I'm not assuming it's a bug, just that I don't quite understand something ^^
Can someone explain to me how this is supposed to work?
(I am currently using 20.5.613)

Attachments:
UV_Display.png (14.6 KB)

If I'm not mistaken, your issue occurs because Houdini does not recognize all of your UV attributes as UV attributes.
When you create UVs with standard Houdini nodes made for the purpose, they get a hidden flag that they are indeed UVs.
But if you create an attribute with a name that seems like the name of a UV set, or copy and rename one, it might not do that. If you middle-click on the node you might see something like:



You can set an intrinsic attribute to tell Houdini that you are indeed creating UVs:


This code probably works in different wrangle modes (Detail, Vertex, ...), but you need to only set it once, so it's best to run in Detail mode:

setattribtypeinfo(0, "vertex", "uv3", "texturecoord");

Attachments:
uvs_and_not_uvs.png (292.0 KB)
Vex_to_make_UVs.png (284.8 KB)

Hi DASD,
thank you for your very comprehensive answer, I didn't know that!

Unfortunately, in this case this doesn't seem to be causing my problem, since all uv attributes seems to be recognized as UVs already.

I tried to set the intrinsic attribute anyway, but it made no difference.

The behavior seems to be very difficult to reproduce, it is hard for me to describe a clear repro case. Sometimes Houdini accepts e.g. uv2 in the display options and also shows it in the viewer, but as soon as I pan or zoom the view in the viewport, it switches back to uv1 (both in the viewport and in the display options).

I tried to do the same in a simplified scene, I got that same behaviour there too

Maybe it is a bug after all, I think I will report it to sideFX.

(I will update this ticket when I get new information)

Attachments:
NodeInfo.png (11.1 KB)
Simplified.png (622.2 KB)