Creating and Editing Texture Coordinates (UVs) - An Introduction to Computer Graphics for Artists - page 147

Fig. 10.2 This model has undistorted texture coordinates and clean maps (Image courtesy of
Daniel van Leeuwen)

Fig. 10.3 Both of these UV layouts are about as effi cient as they can be given the shape of the
objects they are connected to

10.2 Projection

To apply a texture map to an object, it must fi rst have texture coordinates. Most
polygon creation tools will provide automatically constructed texture coordinates,
but by the time you are done working on your model, these coordinates may be
unsatisfactory due to topology changes from the modeling process. If you need to
correct the existing coordinates on a model, or create new ones from scratch, you
will have to project the coordinates. A projection is similar to what happens
when light is shone through fi lm in a fi lm projector. Rays are cast from the light
source within the projector. The rays intersect the transparent fi lm and as they pass