Greetings to all.
Is it possible to somehow offset the UV coordinates in a shading network beyond the usual [0, 1] space? I am trying to do this to force the image node to return the texture value of a specific UDIM tile.
I know that this can probably be done with the uv_coords input on the image node, but the manual states that using this input can have a detrimental effect on rendering performance. It looks like uv_transform could probably do something like this, but it seems to insist on wrapping the UV coordinates to the [0, 1] space in some manner.
Is something like this possible without writing my own shader to do so?
The image shader uses the original UVs from the mesh to locate the UDIM tile, that's why the uv_transform has no effect here.
I think your best option is to override the uv_coords, or use a custom UV set. Don't think it will cause a noticeable overhead to be honest.
Here's a simple example of a network which overrides UV coords of an image shader with a modified U coordinate: