On 2012-09-26, at 05:08, Steve Thomas <sthomas1@gosargon.com> wrote:
changing forward direction should not IMNSHBOWO change heading.

Wrong indeed ;) It's actually quite simple:

Not the first or last time. The only thing good about being wrong is when I find out I learn something new! Thanks.

One way to think about it is that the forward direction describes the rotation as seen from the inside of the object, and heading is the rotation as seen from outside. You almost never have to use the numerical value of the forward direction because it only describes in which orientation the object was painted.

This is perhaps the best and simplest explanation yet.

HTH,

It definetly helps.