UV Texturing is how you texture inside of Blender. It can be quite difficult, so this tutorial will help you learn the basics of unwrapping/texturing simple meshes. You will also learn the basic techniques in unwrapping complex textures.
Yes. Well, sort of. UV texturing isn’t exactly the proper name for it. UV mapping is the correct name for the verb. UV mapping is the art of taking a 3-Dimensional mesh and applying a 2-dimensional image to it, using UV maps. UV maps are basically 3-D meshes that have been cut up. Each face gets a certain part of the image applied to it. There are many tools included with Blender that make UV mapping end with better results. UV mapping is much different from texturing, because you can select what part of the image you want to display where. With texturing, you can only apply the texture to the mesh, but not much more. Here is a picture to show you the difference (taken from Wikipedia). This picture shows you a sphere mesh without and with UV mapping, respectfully:
Getting Your Mesh Ready
You will need to open Blender and find the object you want to unwrap. I would suggest that you put it in an empty layer, but that’s entirely up to you. Now, be sure you’re in editmode, and press ‘F’. Now you are in Face Select Mode. Now you have a few options to choose from, depending on how your mesh is set up. You can use one of the commands to unwrap it automatically (less reliable when working with some meshes), or you can manually go in and unwrap it manually (only as reliable as your ability to unwrap).
Now, we’re going to set up the viewports to view the texture and the results from our unwrapping. Place your cursor over the line splitting the 3D Viewport from the Buttons Panel. Your cursor will change to a vertical double-arrow. Right-click, then select “Split Area.” Move your cursor over to determine how the viewport is split. Left-click to accept the changes. Now you will have one more viewport. Change the current window type of one of the Viewports, by selecting the following option:
There are different techniques to unwrapping objects with almost automatic techniques, I will go over some of the most well-known techniques. As a side note, when I say select all, you can skip that step and just select the faces you wish to unwrap.
Primitive Unwrapping is one of the most basic forms of unwrapping is primitive unwrapping. You can unwrap such primitive meshes as cubes, cylinders, and spheres. So, if you have a primitive mesh you wish to unwrap, go into Face Select Mode (F), then select all of the faces (A), and then press the unwrap function hotkey (U). You now have a lot of different options. You should select “Cube from view” for cubes, “Cylinder from view” for cylinders, and “Sphere from view” for spheres.
Unwrap using smart projections is a time-saver for unwrapping in some occasions. In the face select mode (F), select all of the faces (A), then go into the UV calculation menu (U), and select “Unwrap using smart projections.” Another menu will pop-up, and you will have the chance to mess with the calculations. Feel free to experiment with this, and try to find the perfect settings for your mesh’s UV calculation. I usually stick with the default settings.
Unwrap can sometimes be used for unwrapping, but sometimes it doesn’t work at all, making it less reliable. I use this for some meshes, but it’s not my #1 pick. To use unwrap, first go into face select mode (F), then select all (A), then go into the UV Calculations menu (U), then select unwrap.
Manual UV Mapping
Some of the features I have talked about in the Automatic Unwrapping section doesn’t give the best results. I would have to say that the best form of unwrapping is the manual way. Sure, it’s a lot of work, but it’s well worth the effort, and it also saves the texture artists a lot of work.
Project from View is one of my most used UV calculations. I use it for projects (especially architecture and objects). It is ideal if you want your texture to have different parts, but keep the same structure your mesh has (which also makes it easier to spot what part of the texture is what. To use it, go into face select mode, then select the faces you want to unwrap, then get the viewport to face directly at those selected faces. Go into the UV calculations menu (U), then select “Project from View.”
Vertex Manipulation is the final technique. Select the faces you wish to work with, and select verticies in the UV Image Editor, by right clicking them and manipulating them like you would with a normal mesh. The only difference between the two is that you cannot make new faces, and there is no Z-axis, only the X and Y axis exist.
Well, now that we’ve learned a little bit about unwrapping, we can learn a bit about texturing. Now, by texturing, I mean getting the UV ready for texturing, and exporting a wireframe UV for the texture artists to work from. You want to make sure that you don’t have overlapping faces (unless you want the faces to have that same part of the texture applied to it). Another thing to watch out for is making sure you know which part is where. My method isn’t exactly ideal, but it definitely gets the job done. I take a snapshot of the mesh’s UV map, and number the parts, and I also label groups of faces on the mesh with the corresponding number on the maps, so I know what part of the mesh will end up on the mesh. I sometimes just use names of the different parts, rather than numbers, because it can be much simpler to understand.
Once you’re ready to export the UV’s wireframe, go to the UVs menu -> Scripts -> Save UV Face Layout. Select some of the options, then press enter, then save it to a place you’ll be able to find it easily. Go into your image editor (preferably Photoshop or GIMP), and delete the background, leaving the wireframe only. Keep the Wireframe as the top layer at all times, so you know where the wire is, but don’t forget to hide the layer when you save (or else the wireframe will appear on your object).