I know this topic is more related to 3D issues than Unity itself, but considering Unity as a game engine this might be a good place to talk about it and perhaps help others with similar questions.
We often use UVmapping for organic models such as characters and few simple objects as well, like lamp posts, chairs, etc. As a noob in Level Design, I wonder what’s the best solution to texture all objects in a level that varies from a simple model to a complex model that might be hard to open in a UVmap (a big rock wall, for example).
My question is: Do we really have to open all non-organic objects into an UVmap? What other solutions might be instead of opening each object into a 2D plane and texturing it?
Right below there are some examples that I’m not sure of how they were made.
if we use the rocks in AngryBots as an example: I can’t open the FBX files, so I’m not sure if they’ve used any kind of UVmap or if they have used some sort of script in the shader (?) to tile the texture.
The same goes for the floor: As you can see, it seems that they’ve coordinates how the texture is mapped on the mesh, but the texture itself doesn’t corresponds to how the mesh is actually displayed. Note that they use the same texture on two different objects and they aren’t display like eachother.
There’s such a thing as a tri-planar shader that will texture things like terrains automatically, but for the most part you just UV unwrap all models. It’s not hard if you have decent software (Blender is fine) and some practice. Find some tutorials on UV mapping.
The bots rocks were UV-mapped, as were most everything in the bots demo.
The floor textures you’re showing there have been composited from two different sets of UV coordinates for the same mesh. One UV map describes which portion of the “clean” tiles texture is used for each small square tile of a large floor area. Tiles can be rotated and flipped and reused many times. One UV map describes a larger, lower-resolution map where lights and shadows can be baked in; it’s in shades of clear or black or light colors, depending on what light or shadow they want to apply. Since the shadows fall on different areas, it really helps break up the monotony of a very limited tile set like you show here.
Blender has a couple nice features that help unwrap a mesh into one or more specialized UV mapping layers. The “Smart UV Unwrap” is good for manmade objects like machine parts and building modules. You don’t need to choose seams and you can take all the unwrapped bits and pieces and reorganize them all over your tiling textures (sometimes called an atlas texture). The other unwrap modes are each designed to be useful for various kinds of geometry, and often depend on you marking out certain cuttable seams. Unwrapping humanoids is fairly difficult, as you want to maximize the UV resolution for important areas like faces and ears and fingers and uniform insignia, while not distorting the shapes so much they’re hard to hand-paint.
