Nonphotorealistic techniques used in computer graphics vary greatly in their level of abstraction.
This would be inappropriate for most technical illustration. As can be seen in this first slide, most NPR work consists of image processing or paint program like systems where generating an aesthetically pleasing image is the primary goal. In computer graphics, there has been little work related to technical illustration. However there is a body of work which has concentrated on communicating shape information by emphasizing certain details as shown on the second slide. For these works, generating an aesthetically pleasing image is a side effect rather than a primary goal.