ISO 10303-214:2010(E)
A Direction defines a general direction vector in two or three dimensional space. The actual magnitudes of the components have no effect upon the direction being defined, only the ratios x:y:z or x:y are significant.
NOTE 1 The components of this entity are not normalised. If a unit vector is required it should be normalised before use.
The direction_ratios attribute is a list, the individual elements of this list are defined below.
© ISO 2010 — All rights reserved