real world size uv mapping?

HammerFist3D2D

i know that real world size means to make your model big like in real world .
But I also heard that it makes uv mapping easier, why, could you please answer me, can you make some excamples with pictures when you do uv mapping with real world size and with out it. And do you use it or not?

fatihG_

If I understood correctly.. "real world" size is just an unit thing.
It helps keep the texture density over multiple assets the same, thus making it more consistent.
Every square meter gets a pixel density of 256px² for example.

This means that a 1m x 1m wall will have the same size of texture space as a any other piece of geometry, like a car or whatever.

HammerFist3D2D

so real word uv mapping just mean that when I uv map wall big 1m x 1m, it will take only 256x256 pixels of texture picture?

fatihG_

No, that was just an example.

Im not sure calling this "real world" is accurate though.
It just means that every surface gets the same pixel density.

So for example 1m² could get 512*512 texture space, while a 0,3m x 0,3 that only 1 third of that, about 170*170 pixels

HammerFist3D2D

man, i am not idiot, i know its not just for walls xD, but there is thing in uv mapping that can be thicked, it is called real world size xD

Eric Chadwick

It only makes sense to use when you have a photo texture of known size, and you want to match that scale, for example with architectural rendering. Tutorial... http://www.cgdigest.com/uvw-mapping-with-real-world-scale/

Noors

Thing is if you uncheck it, max will normalize your uv projections => stretches everything in the 0-1 square.
If you use real world, it wont, and yeah also, 1 unit in 3d will be 1 unit in uv, so you're sure that all your objects will have the same ratio.
I personnaly unwrap everything in real world, then scale at the end if needed but clearly this is more useful when doing buildings than a character.

That corresponds to uncheck normalize in the unwrap too.

Eric Chadwick

Interesting!