UDIM interrest?

Hi all :slight_smile:

I’ve reading many things about UDIM but…

i’m really sorry as i don’t understand at all the interrest of the thing :confused:

splitting UVs along several 4K maps, instead of setting them all in one bigger map ?

what is the aim ?

Has anyone some clear explaination ? or some links to tuts/infos ?

thanks in advance !

And happy blending ! :slight_smile:

UDIM is kind of like creative a massive texture, but it is divided into tiles and can be expanded whenever it is needed.

The major benefit is with UVmapping, you don’t need to try to cram and arrange the islands in a way to maximize the number of pixels allocated to them within a 4K or 8K square, but as you unwrap more of your model, your new islands can be placed in a different tile so you have tons of pixels that can be painted on.

For Blender, there is an actual patch from Lukas Stockner that is fully functional, but the workload of the devs. to get 2.8 out the door is such that they are not accepting any massive new features right now. It could still come early in 2.8x though when the current feature freeze is lifted.

hey @Ace_Dragon !

thanks for your answer !
For blender i use a nightly post 2.79b. ( needed the AO node )

i still don’t understand the benefit of UDIM :confused: ( am prolly stoopid as obvious things come to me lately :stuck_out_tongue: )
4 textures of 4K is the same as a 8K texture

  • takes the same place
  • gives same final resolution/detail
  • is slower to handle than a 8K texture ( handling 4 textures in gimp is not as simple as one 4 times bigger )
  • gives… well what ?

apart the specific thing: add one more tex because i need it…

I use tu use 8K textures with a lot of free space in them. and as needed, i populate it with images i need ^^

Am still searching the benefit of UDIM :confused:

regards and happy blending !

The idea behind UDIM is to paint the texture directly in the DCC software, one of the things Lukas’ patch does for instance is paint across tiles, because all of your tiles are visible in the viewport at once. It’s not really meant to be worked on in GIMP save for some smaller edits.

In addition, having something like a 16K texture instead of 16 tiles will take tons of RAM, tons of VRAM, and tons of CPU cycles to handle in a proper fashion. UDIM’s design theoretically allows for some optimizations that would otherwise not be possible.


Hi, one of the features of UDIM is to have different resolution in each tile of the whole texture. For small parts or not important parts you can use 1024 for other 2048 and so forth.
Here in Mari:

Cheers, mib

awww… i love those kind of discuss !!! :smiley:


isn’t 16K textures just as big as… say… 4x4 matrix of 4096 texture ?
16Kx16K is 268.435 K pixels
4Kx4K is 16.777pixels

16 times ( 4x4 ) 4K textures is just the same 268.435K pixels :wink:

so it’s not a matter of tons of RAM nor VRAM :stuck_out_tongue:
nor CPU cycles.
I’m okay for the optimization idea but i really got to dig in this as it’s still really not obvious to me.

i’m really sincerely asking trying to understand what is the benefit ( and believe me i pray there’s one :wink: ) and i’ll kik asses till mine is kiked x))

till now i really see nothing that make me say: ‘shit i’m a stoop moron ! i didn’t see that !’
With my 16 tex i can do as much as 4x4 4K tex with less pain ^^
proove me i’m wrong :wink:
regards and thx for your time !

happy blending !

hey @mib2berlin

i didn’t catch this !
this makes sense ! much more than the ‘atlasing’ principle.
This means that on the parts of the model you want very high details you can have some. and on less interresting parts, just get 512x512 textures and it’s okay.

am i right ?

this means this system is a cam/viewer oriented system and it’s efficient only if you sacrify some zones of your mesh that cam won’t get close to, and emphasize some other parts on wich cam will… zoom ?

am i still right ?

if i’m, now all this really makes sense to me. even if i realize it’s not what i need :wink:
Because if you consider, in an free visit FPS you can get close to any part of a mesh, this system is not interresting at all, as each par of the mesh has to be as detailed as any other…

I wish i knew mari :confused: for catching all this much better…

Anyway thanks a bunch for your explainations !

regards and… happy blending :slight_smile:

You say the patch is fully functional, but is it available to the public in any way? It’s kinda important to my preferred Substance Painter workflow, so I’m desperately trying to be patient until it’s ready for wide release in 2.8x whatever. I do wish they’d been able to work it into the actual 2.8 release though.

It’s living in its own branch. Look it up in the tree. The problem is that it isn’t up to date with current master. At least last time I checked. You can compile it but it will give you a 2.8 state from last year. September I believe. Not sure and am not eager to look it up on mobile.

I’ve actually made some nodes that allow you to import UDIM textures into blender that work on any version
and to export you only need to use the UDIM grid I provided

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interresting :slight_smile:

would be nice if we could modulate textures of each face with some splatmapping :wink: