uv question

[samuel_the_hamster]

is uv only a projection a 3D model's surface to a 2D image for texture mapping or can i have for example, a number of uv mapping, like hey i have 2 uv's? is that possible and what that even means? 2 projections of the texture

thanks in advance, dave 😄

[samuel_the_hamster]

2 or any numeric value

[davescm · Accepted solution]

UV unwrapping is the unfolding of a 3D mesh surface onto a flat plane. That involves creating seams where the mesh will be cut and deciding where any distortion introduced in that process will lie. The main aim is to keep individual surface elements (UV islands)  from overlapping and to try and keep the scale even.

You are not limited to unwrapping onto a single square. Unwrapping onto several squares is a common process and gives scope for more detail on the model. 

UV projection is slightly different. That refers to how a texture is projected onto a surface. In UV projection it is projected onto the flattened UV map. There are other projections, (Substance Painter offers several) such as tri-planar where the texture is projected onto the 3D surface in all three dimensions, regardless of the orientation of the UV islands. Which works best depends on both the model and the material being projected.

Dave

[samuel_the_hamster]

Hello, Dave!

So when I have 5 uvs I refer to unwrapping in 5 pieces right.

Did not understand very well the difference, both are flat maps? 

[davescm]

No that is not quite correct, the number of UVs is not about the number of pieces (or islands) that the mesh surface has been split into. 

You can unwrap a model's surface into as many pieces as you need, and lay them out on a single uv tile. Alternatively, those unwrapped pieces can be spread over several tiles (UDIMs) allowing you to take advantage of a greater level of texture detail than a single square could achieve.

Dave

[samuel_the_hamster]

Ultimately, the more UVs the more detail?

[davescm]

It can be used that way - or multiple tiles could be used to introduce a different level of detail in different parts of a model surface, e.g. on a person, more detail in the face and hands, less in the body.

Dave

[samuel_the_hamster]

Thanks for explaining me with such patience Dave, I appreciate it a lot.