Let me try (A degree in physics must be useful somewhere)

For a LEFT handed Coord. sys.

1)  Place the 4 fingers of you LEFT hand so they point in the +X direction.
In the default configuration of POVRay this is heading off the Right side of
your moniter.

2)  "Curl" your fingers so they move from +X to +Y.  Again Default POVRay:
"curl" from right to top of your moniter

3) Your thumb now points in the direction of the +Z axis.  In the example
above "into" the screen.



"Kaveh" <kav### [at] delete_thisfocalimagecom> wrote in message
news:1flwt0q.1eoksy3ek3y68N%kaveh@delete_this.focalimage.com...
> Warp <war### [at] tagpovrayorg> wrote:
>
> > Kaveh <kav### [at] delete_thisfocalimagecom> wrote:
> > > I find it easier just to use the curled fingers method, not the index
> > > and third fingers. To get the sense of the z axis, I position the left
> > > hand such that the four fingers curl from the x to the y axis. Then
the
> > > thumb shows the direction of the z axis.
> >
> >   That description was very unclear. I did not visualize at all which
> > direction the thumb is pointing at...
>
> It was not clear, I agree. I will put it another way. Put your left hand
> in the 'aerobics' position, with fingers curled. Now, point your thumb
> in the +z direction. Now if you were to rotate the x axis to coincide
> with the y, it your fingers are giving the correct direction.
>
> In a right handed system, sometimes a screw is used. If the screw has
> its tip in the +z direction, turning the screw from x to y pushes the
> screw in the z direction. But this is of course opposite to the
> left-handed system.
>
> All easier to see of course than to describe.
>
> I just find it easier to have something real like a screw, than to
> remember a mnemonic.
>
> --
> Kaveh

Post a reply to this message