Wasn't it mephuser who wrote:
>How do I Perform Transformations on Isosurface, like Scale, Shear, Rotate>etc?
I suddenly had a thought about how to do all these by variable
substitution, and have written it up in my isosurface tutorial.
<http://www.econym.demon.co.uk/isotut/substitute.htm#shear>
--
Mike Williams
Gentleman of Leisure