Why are there only 8 uv map slots?

I have mentioned this before some years back. Is there any reason why blender hard codes a limit of 8 uv maps?Why not just leave it unlimited ?Seems rather strange that this is still a thing.Is it to do with memory?Is it a software limit?

always had only 8 slots

if you need more use cycles

happy cl

I don’t know why you need more than eiht maps, but it’s a strange limit. Anyway, I have tried and you can create more maps in a “original way”. You can join different meshes with different UVMaps names and the UVMap limit is not respected.

Each material in Bl is limited to 8 slots of Textures only!

not certain if you join if limit is higher per material but I doubt !
Now you might also get more materials then more textures slots

happy bl

The coherence between texture slots, materials or whatever with number of UVmaps id have no sense. You can have a backup of the UVmaps with duplicates of the UV Map. Maybe have some technicals reason, standard or convention.

In any case Bl won’t be there In 2.8 so get use to cycles now
will be easier to work with 2.8 and faster !

and cycles limits has been increase a lot more so should not be a problem

happy bl

I have tried in cycles and the limit is the same

as I remember limit for UV image was increased a lot more this year
but don’t remember to what value

and certainly not = 8 it is much higher then 8 !

not certain why you would need so many anyway
show us some specific case

again object has many material with many texture
should not be a limit for most application !

happy bl

Not UV Image; UV map:-

sorry I mix the qty of unwrap and UV image in nodes set up!
not certain why that qty of UV map/unwrap is in cycles
never really used that one method very often

I know that number of image UV was increase this year I think

there are some addon to combine UV map
one is the


and certain there are other addon to help

see this thread on addon

happy bl

been trying to do this “Special method” but must be doing it wrong can u post the steps please.?

You got an answer to that in March 2016: The OpenGL parameter GL_MAX_TEXTURE_COORDS seems to be limited to 8.

So i did forgot about that

Just curious, why do you need so many UV Maps?

Its not hard with projection painting take a human you have 3 or 4 refs just for the basic shape then you want better images for the hands feet at least 2 apiece inside of the mouth tongue teeth at least 1 image a piece hair maybe want different from main source so that’s 4 more then you have normal map spec map ao map maybe displacement map 8 went out the window a long time ago.

That’s a quite clumsy way to do it… If you use different materials for each different texture, you’ll only need 1 uv map. I can identify three or four situations in all my life that i used more than 1 uvmap.

What you’re describing is a problem that has long been solved by UDIMs. Wanting more than 8 UV slots is like people asking Henry Ford for faster horses. The real goal is to get UDIM support in Blender’s painting and UV editing tools.

Orthographic projection painting, i totally forgot about that.

I agree UDIM is the way, but also the restriction to 8 UV slots is somewhat arbitrary. I am sure it has something to do whit limited resources in the past, but today the restriction is unnecessary and should be removed if its a trivial thing to do. The non-trivial thing is the UDIM implementation.

Aren’t UDIMs available by using Renderman?

Is that for cycles I use render?I know in render if i create a new material it shares the same uv maps

Never heard of a UDIM before