Why are texture coordinates often called UVs? Is there some historical reason texture coordinates are often called UVs? I get that vertex positions are x, y, z but even OpenGL has TEXTURE_WRAP_S and TEXTURE_WRAP_T and GLSL has aliases so if texture coord is in a vec you can access it with

someVec.st


but not

someVec.uv  (these would be the 3rd and 4th elements of the vector)


And yet pretty much every modeling package calls them UVs Maya, Blender, Unity, Unreal, 3dsmax

Where does the term UVs come from? Is this a known part of computer graphics history or is the reason they are called UVs lost in pixels of cg time?
This is not a definitive answer, but it is generally accepted that Ed Catmull introduced Texture Mapping in his 1974 thesis, &quot;A SUBDIVISION ALGORITHM FOR COMPUTER DISPLAY OF CURVED SURFACES&quot;
In that, he uses (U,V) to access the image data (see the page labeled 36 in the above)

MAPPING
Photographs, drawings, or any picture can be mapped onto bivariate patches. This
is one of the most interesting consequences of the patch splitting algorithm. It
gives a method for putting texture, drawings, or photographs onto surfaces....
...If a photograph is scanned in at a resolution of x times y then every
element can be referenced by u·x and v·y where 0&lt;=u,v&lt;=1. In general, one could think of the intensity as a function l(u,v) where I references a picture.

I believe this thesis also introduced the concept of the Z-Buffer (Page 32)