UV texture size affects the normal map?

STinko · Apr 2008

Hey guys,

I put an entire UV unwrap in 1 map of a dinosaur (1024 x 1024) . I was thinking of putting the unwrap in 2 seperate maps where 1 map would be the entire head, and its horns and the other map with just the body, and legs.

While doing zbrush, I was wondering if the Normal would be better distributed in 2 maps than 1 uv map? At the moment, I realize that the head of my uv model is more detail than the body. ( in 1 UV Map)

-stinko

Xaltar · Apr 2008

More UV space = more POTENTIAL for normal map detail. However, most people don't actually put enough detail into their highpoly to warrant multiple uv sheets. So your answer is simple, if you have a lot of small details in your model then the larger UV space will be usefull. However, if your detail is not as fine then you can get away with a single sheet @1024. I always try to fit everything on to one sheet (with the exception of character models) as it makes working on textures easier and makes the asset use less resources in a game engine.

STinko · Apr 2008

Xaltar, that answer my question exactly mate~! thank you so much~! Im sorry to be so new to Zbursh/ maya, Ill try to get better at the technical side of things~ since my model is a character, I'll use 2 maps and try it out.

Xaltar · Apr 2008

No problem and good luck to ya. I am fairly new to sculpting and normal maps too so I just repeated what I have seen around the forums here

Eric Chadwick · Apr 2008

Xaltar wrote: »

I always try to fit everything on to one sheet (with the exception of character models) as it makes working on textures easier and makes the asset use less resources in a game engine.

The reason this is true is because when you divide a single model into multiple materials it then has the potential to slow down your frame rate.

As the game engine draws the vertices/triangles of your model, it has to stop drawing whenever it encounters vertices/triangles using a different material. It then has to process these different vertices/triangles through the graphics hardware before it can resume rendering again. Kind of complicated, but it's this stopping and starting that can slow things down.

Also using more textures usually means more memory, which is always in limited supply, so that can slow things down too. And framerate is the king.

STinko · Apr 2008

So I got 2 UV MAPS. Should I make 2 OBJ file, 1 for the Head and 1 for the body, or should I just make 1 OBJ file for Zbrush?

Michael Knubben · Apr 2008

It shouldn't be true at all that the head has more detail than the body in the texture-map. Did you just use an automatic unwrap and leave it at that? It's entirely possible to scale the different pieces on your uv-map, and make it so the head has just as much detail as the body. or did you mean that the head is more detailed on the model, and would therefor require more uv-space? If so, just scale it up, although that way your body will be more pixelated than your head, which could look bad.

Xaltar · Apr 2008

Yeah, mightypea has a point. I always apply the checker material to my models during UV mapping so I can scale all the parts so that the checks are the same size. After I have everything the same scale I then go back and scale up areas that need more detail but only slightly so as to keep the pixil density at least close to uniform. If after doing this I still can't fit all my detail on the map I then break it up into 2 sheets. Don't forget to try and match the checker scale on the 2 sheets as closely as possible. It looks really ugly when for example a head looks like its at 1024* and the body looks like its at 512* or 256*. Always try and keep your pixil density as even as possible and you should be good to go.

UV texture size affects the normal map?

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