Hi df,
UV mapping refers to a coordinate-based system for applying a 2D image to a 3D object. It can be very precise and is especially useful for mapping images to organic shapes.
The U and V refer to coordinates on the image, which are linked to specific locations on the 3D object, which are defined in X,Y and Z directions in 3d space. The methods for setting this up vary by the application used to model the object.
UV mappping is just one way of mapping images to objects. Many 3D apps support spherical, cylindrical and other methods… but so far as Invigorator or ProAnimator go, you need to set up UV mapping in the modeling application used, and include that data with the model, in a supported format.
I hope that helps.
Jon