"SharkD" <nomail@nomail> wrote:
> "Rune" <aut### [at] runevisioncom> wrote:
> > "SharkD" wrote:
> > > Anyway, the above code
> > > works (as far as I can tell); I super-imposed it over a rotated version of
> > > the
> > > "top side oblique" rendering I completed earlier, and everything lines up
> > > perfectly.
> >
> > Is it intentional that the side facing the camera is a slight rhombe and not
> > a perfect square? You'll see it if you render with a for example 640x480
> > resolution. If this is what you call the "jagginess due to roundoff errors"
> > then in my experience, these errors are far too large to just be rounding
> > errors.
>
> Well, the face of the cube only diverges from a perfect square by one pixel i
> each direction at 640x480 resolution. Yes, I would call that "jagginess".
>
> > The camera below will give an identical image, exact that you get a perfect
> > square (no "jagginess"):
>
> That does work a lot better. Could you try a shot at this image?
>
> http://img139.imageshack.us/img139/7937/obliquetoprotatedgm6.png
>
> Also, you describe how you derived the float values?

0.7 ~ 0.707 ~ 1/sqrt(2)

use 1/sqrt(2) for the exact value and everything should be correct and similar
to the one I posted as well.

I put together a little diagram that I hope can explain the basic geometry
behind the numbers  (thi shows cavalier projection, for cabinet, the depth
becomes 1/2 and 1/sqrt(2) becomes 1/2sqrt(2))
http://i69.photobucket.com/albums/i52/barberofcivil/Oblique.jpg

-tgq

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