+ What is UV Mapping?
References
UV Mapping is a process where every part of a 3-dimensional mesh is laid out flat onto a 2D graphic (known as a texture map) so all faces of each part can be textured individually.
For a simple example, this 3D cube has been laid out flat so that all of its 6 sides can be textured separately (click the image to see a larger version):
What are U and V?
The name UV Mapping is derived from the makeshift co-ordinates U and V. Meshes in 3-dimensional space use three co-ordinates: X (for width), Y (for height) and Z (for depth), but height and depth can't be shown differently on a flat texture so, to avoid confusion, when we refer to vertices on the 2D texture map we use the letters U and V (for example: "line up all vertices along the U axis"). You can see these labels on the above image: U represents horizontal co-ordinates, and V represents vertical co-ordinates.
How do I make my UV map a particular size?
You don't. Basically, a UV map is proportional: it will shrink or expand to fit any texture size you create for your mesh. The above texture map for the cube would shrink to fit on a postage stamp or a narrow rectangular shape if you created textures of that size. Equally, it would expand and stretch to fit a much larger texture. When you import your mesh into Workshop and then create a multiplier for it (see: What is a multiplier?), your UV map will stretch or expand to fit your multiplier's size and shape. For creating the correct size textures, see What size should my DDS textures be?
What tools do I need to make a UV map?
Many 3D programs (see: What programs do I need for meshing and 3D modelling?) have UV mapping (sometimes called texture mapping) built in. Generally, the default shapes (primitives: see What is a primitive?) are pre-mapped, though how well they have been mapped depends upon the program. For example: Milkshape maps all sides of a cube to fit the UV map 100% width and height (all faces overlapping on the map) and it maps the tube of cylinders but not the end caps. Often, using a third party program to unwrap your model is the best place to start (see What is UV Unwrapping?).
Are there any tutorials here at TSR?
Most mapping tools are accompanied by tutorials (usually hosted at the site offering the tool), but for specific tutoring on mapping your first mesh, see Object Creation Part 1: The Beginner's Guide To Meshing.
Referenced from:
- Resource What has changed in Sims 3 creating?
- Resource What size should my UV maps be?
- Resource What is a primitive?
- Resource What is Unwrapping?
