UDIM rendering with Virtual Textures

[NatXotic]

Hello,

I posted this in the possibly wrong thread about Virtual Textures, so I wanted to extend this t the community who has maybe a solution for me.
https://forums.unrealengine.com/unreal-engine/feedback-for-epic/1618618-virtual-texturing-feedback/page17#post1824334

I am trying to replicate a bit of VFX work in Unreal and see how close I can get it. Now I am struggling with one basic thing already.
I have a character with UDIMs imported as an alembic cache, I have the UDIM textures as exrs and they import fine as Virtual Textures (Virtual texturing enabled and show VT in the bottom right corner)

When adding the VT texture to the base colour input of my material and apply the material to the entire static mesh, I get the UDIM 1001 correctly applied, but all other UDIMs show incorrectly.

When I view the texture in the editor I see the layout of all the textures (are they supposed to show UDIM 1001 in the top left corner and 1011 underneath? - different than UDIM standard)
The Static mesh has 2 UV layouts, but I use the main one representing the texture UDIMs, Otherwise UDIM 1001 would be incorrect
When I toggle the UV Layout on, in the static mesh editor I can only see UDIM 1001, a bit of 1002 and 1011. Here the UDIMs show correctly laid out with 1011 on top of 1001 and 1002 to the right of 1001. Is there another UV viewer where you can zoom out a bit?

So, I am not sure what and where things go wrong.

How are the UDIMs supposed to show up in the texture editor?
Can I see more of my mesh’s UVs, beyond 1001?

How do I get the other textures to the correct UDIMs?

texture naming is:
asset_basecolor.1001.exr

Thanks a lot

[Suthriel]

Wait until 4.26 is released, because they adressed and corrected this issue in 4.26 Had a model too, that got it´s textures arranged in the wrong order in 4.25, but the very same model imported into the preview version of 4.26 worked flawless, with all virtual textures sorted as expected.
The problem was, that there was NO standard for how those textures had to be sorted, and for 4.25 they used the sorting order with starting in top left and going on like reading a book. But most people and their progams seem to work the opposite way, starting at the bottom and then going upwards(this order is introduced in 4.26).

[NatXotic]

@Suthriel

Wait until 4.26 is released, because they adressed and corrected this issue in 4.26 Had a model too, that got it´s textures arranged in the wrong order in 4.25, but the very same model imported into the preview version of 4.26 worked flawless, with all virtual textures sorted as expected.
The problem was, that there was NO standard for how those textures had to be sorted, and for 4.25 they used the sorting order with starting in top left and going on like reading a book. But most people and their progams seem to work the opposite way, starting at the bottom and then going upwards(this order is introduced in 4.26).

Thanks a lot. Will wait for 4.26 then seems it has a few more rendering features I would want to play with as well. E.g. MultiChannelExrs

[TeaspoonVFX]

I am having the exact same issue – and I AM in 4.26.2

All same things:

Only reading 1001 in the UV visualizer.
Only mapping to the 1001 tile.
Not being able to see other UDIM tiles

Were you able to resolve this?

[jojojonasnas]

I have this problem, too, with 4.26.1. Only 1001 is shown.

[jojojonasnas]

I solved it: I forgot to enable Virtual Texture Streaming in project settings - it works now!