Is there a limit to UDIMS?

WarriorOfOld

I am creating a turret hero prop. When I bake with 2 UDIMs the normals are jagged, I've upped it to 6 UDIMS and they come out cleaner. The question I have is are they a limit to the amount of UDIMS I should use?

Neox

Jagged as in pixelated? Can you show your issues?

Sounds like a texel density issue, which might or might not be solved with more UDIMs

WarriorOfOld

Yeah it was pixelated, I fixed the issue with UDIMS!  
I do however have 7 of them, just wondering if that's a reasonable amount. 

Joopson

My advice would be to make sure you have realistic expectations, and an efficient workflow-- before introducing UDIMs at all, let alone more UDIMs.

UDIMs aren't a magic fix-all patch, you still need strong fundamentals or you'll end up working wastefully, and producing assets that are unnecessarily heavy. Just my two cents!

okidoki

You may have to elaborate this to get a more suited answer. Because six textures with six different UV maps (UDIM or not) with the same resolution.. of course will give you a higher pixel density.. or using one six times bigger image in the first place (?).

oglu

Film assets are using hundreds of UDIMs. I would say if there is a limit its really high.

https://x.com/RassoulEdji/status/1790061788773470230

poopipe

USD specifies a limit of 10 tiles in U and a range of [1001, 1100]  giving you 10 x 10 


This will be per texture and presumably per material 

EarthQuake

For a turret prop for games 6 or 7 UDIMs sounds like way too many. This depends on the resolution of each UDIM of course, but as @Joopson mentions throwing more resolution/UDIMs at it is probably not a reasonable way to solve it. In production, you will have a resolution limit that you will need to stay at/under, so making sure that your UVs are efficiently laid out and that you understand the viewing distance and the texel density of the game is critical.

poopipe

This is one of those situations where there's a real distinction between 'can' and 'should'

You absolutely can use 7 texture sets on the turret and there's no reason to not use 7 texture sets on the turret if your use case justifies it
i.e its big and important and you're taking full advantage of the resources you're using 

but..

That is a shit load of texture for a single asset.
- I have to assume 4k or you woudn't be adding more udims to get better resolution.
- Also assuming a standard metallic/roughness material
That is a total of around 420mb in texture memory.

To put 420mb in perspective, it's roughly 5% of the total usable memory on a series S and probably 8-10% of what you're likely to have available for textures once the rest of your content is loaded.

context is key 
if your camera is going to be inside the turret and it makes up most of the visible area on screen for most of the time I'd say you're being quite frugal
if the turret is something you're viewing as part of a busy scene then i'd say you're not 

Kanni3d

poopipe said:

That is a total of around 420mb in texture memory.
To put 420mb in perspective, it's roughly 5% of the total usable memory on a series S and probably 8-10% of what you're likely to have available for textures once the rest of your content is loaded.

TBF, textures on your disk (10 textures of 4k tga -> 420mb) is not the the same amount of resources as it would be in build (far less once converted to DXT/BC7 and compressed into build), but your point is valid nonetheless that this is more of a matter of being pretty reckless with your texture sets

poopipe

I wasn't talking about the uncompressed size

a 4k textureset is around 60mb at runtime for a metallic/roughness material - 7 of those is 420mb 

it adds up fast

okidoki

For..
>  a turret hero prop
..this might be overkill. For some VFX in a movie you might even need more. So this all depends on your use case and the needed pixel density.
I guess the turret will not be used for a "portray" shot but "somewhere on the screen" in a game ??  Again:
You may have to elaborate this to get a more suited answer.

Kanni3d

poopipe said:

I wasn't talking about the uncompressed size

a 4k textureset is around 60mb at runtime for a metallic/roughness material - 7 of those is 420mb 

it adds up fast

oooh yes gotcha, thought you just added up a bunch of textures together for that 420mb sum lol