I saw a video on youtube about UDIM and it was my first time I was texturepainting so I decided to try it to see the method, but after I did it I was left asking myself what was the main idea, and why it was so appreciated.
I found recently an usecase where I find UDIM to be useful. basicaly I created a character and I made it again 4 times, but every time I was removing parts of the topology and adding patches on the holes, so I took those patches and placed them in a separated UDIM tile, and painted them, the tiles allow me to maintain the same texel density for the pieces I added later on after I finished the textures.
Another way I found to use UDIM is to create 2 or 3 versions of the same model, one for game engine and the other for animation that is more complete and has more parts on it… if I create an UDIM tile and place on that one all the pieces I want to remove for the game engine, I will then be able to just have the game engine version of the model on 1 single texture, which makes the file more organized.
I listened to people online and they told me they use UDIM for other usecases, but I always failed to understand completely “what is the point”… I followed also a course on texturng adn the author was using UDIM to separate the face and give it an entire tile of 2K resolution, while body was contained on the other tile 2K. In this situation I understood that UDIM was allowing the artist to assign more detail to the face alone, and obviously have less detail on the body.
The third advantage of UDIM, is that if I understand it right, you can basically have the UDIMs at any resolution you want, so basically you could have main body at 4K and assign another tile much lower resolution, maybe a palette of pixels for the UDIM… Then if you do it, it will be much faster and easier to work with changes of color or material.
Here is the example from my personal usecase. Do you have other examples that could lead me to understand UDIM abit better? Thanks.
…or you just look at this VFX expert 
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