Texturing Question

electricsauce

I made a wall unit in Blender and I'm at a complete loss on how to texture it. I can't seem to get enough detail in the model if I separate all of the uvs on one map. Since this will eventually be a game (arcvis) piece, I was wondering if it is acceptable to use multiple textures for one model.

Also, is it common to use more than one uv map for game models?

odium

Its not only common, its sometimes vital. But it all depends on the engine, the target spec, the visual style etc etc...

Its also a case of six of one, half a dozen the other sometimes. For example, if you only need 696 pixels high of space total over, say, 7 UV islands, then what makes more sense? A 1024 pixel high texture, or a 512 pixel high and a 256 pixel high texture? Well, one is more memory, but less calls. The other is less calls, but more memory. But then, you may be able to fit other things into that texture, from a totally different model... But again, that may actually be a bad idea, because batching and mipping etc comes into play, as well as the fact you may be loading a 1024 pixel high texture for a 100 pixel high asset when the other parts are no longer needed.

So it all depends on the circumstance. Theres no one "real" way to do it, because you need to look at what you're doing first, and then apply the rules to that. As a rogugh guide I would say that its ok to use two uv islands on this piece, as its a large asset and will have both seen at the same time anyway.

electricsauce

Ok, so I ended up making 3 sets of textures. I couldn't fit all of my detail pieces on one map so I did them on two and used on more for the flat areas (cabinet sides, backs, etc). Considering this is an interior asset, at what point would the textures be considered to large for general use? I feel like I'm having a hard time getting a decent wood diffuse texture at 1024 sizes.

I dropped it into unity for a quick check. As soon as I figure out how to add it to UDK with multiple materials, I'll post the results.

Trapd00r

From what I understand, you only get one light-map and that goes in the UV channel 1. The texture maps end up in UV channel 0.... it looks like this thread may describe a good solution for you:

http://www.game-artist.net/forums/support-tech-discussion/17764-multiple-material-ids-uv-channels-universal-ao-map-max-udk.html

electricsauce

I don't have any lightmap uvs on the model (I don't understand why they are necessary), but I was able to import the materials via the method you listed. Blender seems to like to store residual materials somewhere in its data structure, even after they are deleted. This caused my model to have all kinds of lighting issues in udk, but at least I can now get more than one material per model into UDK.

maarten_dominicus

try rendering an ambient occlusion map and overlaying it on your texture (in order to let your shadows be more noticeable, it will also accentuate the edges and make hard angles easier to see). Also try making the wood's grooves not all parallel to each other, I think this will make the texture look a bit less uniform.

As for the lighting issues in UDK; if your model is not triangulated this could be the cause of some lighting issues, maybe some vertices that are not welded (and in the exact same position).

Trapd00r

UDK generates the lightmap for this..it needs to know the UV space for the light..that is why the UV channel 1 thing is important...try shooting the chest with the guns laser...if you get burn marks you should be good...as for blender...try exporting the mesh without "write material" checked in the export>wavefront(.obj) options...and definitely be sure not to have duplicate faces causing you issues....maybe run a merge vertices or remove duplicates with a tolerance set for it.

ivanzu

You need smoothing groups that is why you have this strange shading,just use split edge modifier in blender.