Rect light texture appears reversed in viewport

[SonyBoy]

Just as the title says, I have text on a rect light texture and in the viewport it displays reversed. This is a problem as I'm having to match its placement to another object in the scene with the same text on it, but since this uses a UDIM tile I cannot also use it to texture the light. It also does not update properly or display any other 2D UV edits in hardware shaded mode, so I have to render to see how it's reacting to updates. Very inconvenient.

[seandunderdale]

Yeh I encountered this the other day...I needed a very specific cloud reflection on a part of a car, so I mapped an hdri to a rect light....but it displayed all wrong...it also didnt update the 2d texture offsets I was trying to use to dial in its position. I could crop the hdri, but if I changed my mind, I would be back and forth into photoshops cropping snd re-cropping. Bringing in the texture as a whole, and offsetting in Maya seems more simple to me, but it was made trickier by not having it display correctly. As mentioned, all the tools work as expected in IPR mode, but it adds an extra step to setup.

[hermit.crab]

This is an old known issue (internal bug-tracker id: VMAYA-8534) related to Autodesk. When using procedural textures, Maya bakes them for V-Ray and applies the placement settings in the process, but it doesn't do the same for file nodes. Try adding a checker in both colors of which you plug the File node and see if that renders as it should. Otherwise, I'll speak with the project manager about it.

[SonyBoy]

This is an old known issue (internal bug-tracker id: VMAYA-8534) related to Autodesk. When using procedural textures, Maya bakes them for V-Ray and applies the placement settings in the process, but it doesn't do the same for file nodes. Try adding a checker in both colors of which you plug the File node and see if that renders as it should. Otherwise, I'll speak with the project manager about it.

I don't really understand what you're saying or what you're asking me to do. This was a file node, so whether or not it works with procedurals is moot? And if it's an "old known issue" then why do you need me to confirm that it is indeed still an issue (didn't I already do that?).

[hermit.crab]

I don't really understand what you're saying or what you're asking me to do.

I meant a setup like this (check the attached image).

This was a file node, so whether or not it works with procedurals is moot?

As I said, Procedural textures get placement settings, but File nodes do not. Placing the File node in a Procedural texture fixes the mentioned issue (V-axis flip).

And if it's an "old known issue" then why do you need me to confirm that it is indeed still an issue (didn't I already do that?).

The reason I asked is that the workaround may not work as expected with images with visible text. One may expect a text texture to be projected as it is. However, if we take i.e. a real lamp with a text stencil, the text should be mirrored on the lamp so as to get the correct text projected (as light). This is how Arnold lights work too. In short, you should mirror the text image beforehand.

[seandunderdale]

Yeh this works for me. I plugged a tiff with a logo in, and all the offset 2d tools work in the viewport, same goes for the hdri issue I had. I plugged the 2d file texture into the black and white of a checker....Id need to test render to see if that affects the dynamic range of textures in any way, but viewport tests look ok.