More Modeling Transforms

It is possible to expand our repertoire of modeling transformations. We can add Similitudes, Affines, and Projective groups of operators. However, most of these are either not that useful in everyday practice, or they are commonly reduced to one or two special cases, which generalize via a series of more typical operations.
Among those transforms remaining, scales and shears are the most common:

We can generate any 3-D affine transformation using a combination of a rotation, a scale, a shear, and a translation.

shear [n.]

(§ Homonym: sheer)
1. A machine that cuts sheet metal by passing a blade through it.
2. (Physics) A deformation of an object in which parallel planes remain parallel but are shifted in a direction parallel to themselves; "the shear changed the quadrilateral into a parallelogram."