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View Full Version : What is a UV map?

Mr-Wizard
03-05-2003, 07:01 AM
What is a UV map and where is it used? Some examples would be pretty cool.

Many Thanks

Global Hawk
03-05-2003, 07:23 AM
UV maps are probably the best way to get a regular, well fitted image onto say the human face/body.

Sometimes standard image mapping tools, like planar, cylindrical, spherical mapping can be a bit limiting where the surface is irregularly shaped.
UV mapping is essentially assigning a image map to a point, instead of a poly. Like Tacking the image down, not just laying it over the object and hopping it will stay.

The U and V refer to texture map coordinates and are really not mush different than the XYZ coordinates used in modeling.

I don't have a good example handy right now, sorry! However I'm sure one will pop up soon.
:D

ViperGT
03-05-2003, 07:23 AM

Two, for some examples go here (http://www.tonyg.info/tutorials/LW6/Texturing/UV_Basics.htm)

-Viper

Valter
03-05-2003, 07:48 PM
UV maps will be a new cause for your next headaches :D :D

G3D
03-06-2003, 01:28 AM
I've come up with a useful analogy for 3d classes I teach: UV spaces are like a tailors' templates for cutting fabric.

Another definition is that a UV space is a shorthand representation of group of polygons belonging to one object layer so that they all are visible as flatened 2d group in a square space that uses two coordinates: U and V.

Ideally, none of the polygons should overlap. For example, a cube would look like a lower case t where all six faces are laid out within the square UV space. In many cases, its a good idea for many of the edges to shared in the UV space.

One thing to remember is that of the three main projection methods--planar, cylindrical, and spherical--none have a real intrinsic 'meaning,' because you will almost always want to lay out the polys so that they don't overlap. When they DO overlap, select some of the points that you want to be the 'seam' and unweld them. Move the polys in the UV editor until they are laid out with no overlap. When finished, you can weld the same points back together without messing up your UVs.

Hope that helps.