Hello-
I see a lot of references to “UV,” but nowhere do I see it defined. I doubt it means “Ultra Violet” in Houdini, or does it? It seems to have something to do with textures.
-Scott

It's just some axis labels like X and Y.

Moin, Scott,

it might make sense if you read up on “3d terminology” in general. There are some expressions that you should be familiar with in order to - later on - ask questions in a way other users can understand. Please don't take this as an offence!
UV is such a fundamental concept in 3d that you might just google it

In short - to my knowledge the actual NAMING doesn't have a “meaning” just like “xyz” or “abc” don't have a “meaning” except for being consecutive letters. abc usually is used for variables in some mathematical context or angles on a shape, xyz is used to denominate 3 axis in a 3d space and uv is used for the 2 axis of a 2d space value. In 3d “uv” refers to both material information during rendertime (each polygon/face/primitive - all just expressions for the same idea - is described by its corner points/vertices, but when rendering, you can still have additional geographic information INSIDE the polygon, for normals, bump maps, color etc.). Since the surface of the polygon is understood as a 2d space (even if the polygon is non-planar), you can IGNORE the 3rd dimension on each corner point of the polygon and just see it as 2-dimensional, so that each point inside the polygon can be interpolated onto a standardized, normalized (i.e. square, 0-1 length/height) uv coordinate. By interpolating any point on the surface of the polygon to the normalized 2d space of the uv map, you get unique, exact information about whatever MAP (color, bump etc) you want to read out.

OK … if that was short, you probably don't want to read the long version.

Marc

the simplest analogy is to think of a globe - the points that describe the sphere use (x, y, z) but in order to put an image of the surface of the earth onto this sphere you need to map a 3 dimensional position to a 2 dimensional position.
so UV is like Latitude and Longitude.

Thanks everyone for your help. Yea, I Googled “3d graphics and uv” and came up with some good references. -Scott