How to sample a single UV coordinate with a file node

Tools Maya
#1

Any suggestions on sampling a single point from an image using UV coords on a file node?
I’ve just loaded an image file, and am adjusting the uvCoord attrs, and am seeing no change in the value coming out of outColor

As an example of what I mean… https://drive.google.com/file/d/1rVpKGEfuSw6cm2BPiopsL6lfWr-9GZfZ/view?usp=sharing
I have two similar setups - one using a noise node, and one using a file node.
The noise setup works as expected:
Changing the custom uPos and vPos attrs on the planes, which sets the u and v coordinates, and you see the outColor change.
But the same doesn’t work for the file based setup…

To add to the weirdness - changing the UV coordinates is doing something because the shader preview changes
And as far as I can tell I’m attempting was discussed here - Get color at uv? - but it no longer works as described

Any help would be appreciated!

#2

Hello,

You should be able to do this with a 2d placement node before the file.
Set uvRepeat to 0 and the uvCoord you want to sample goes in the offset.

Hope that results in what you had in mind.
Robert

#3

Thanks Robert.

I was using a place2dTexture node - but the issue is that while everything seems to update (shader changes etc.), the actual outColor attribute stays at (0,0,0).

#4

Hi Paul,

Sorry about that, misunderstood from you previous message.
I had it working in the shader where the color would update but never bothered to look at the channels.
I’ve had no luck trying to get the outColor values to update :frowning:

Robert

#5

Hey Robert,

No worries at all - thanks for taking the time to look at this weirdness!
I think at this stage I’ll report it as a bug to AD.

Cheers
Paul