You almost had me convinced there was a bug.  :-)

However, it is simply a precision error (possibly related to the object
pattern, possibly to u/v mapping on the lathe).  To correct the problem in
this scene, use "40.1" instead of "40.001" in your scene.

-Nathan

"Trevor Quayle" <Tin### [at] hotmailcom> wrote...
> 3.5 beta4 Win2k
>
> I have been toying with uv_mapping, object pattern and transparency to
> create a bottle label and have come across a very odd phenomenon.  Have a
> look at the output of the following code (I will also post the image in
> p.b-t.b).  The two objects are identical copies but, as can be seen in the
> image, operate differently depending on the view.  The lathe is basically
a
> very thin-walled open cylinder with a texture created using the object
> pattern with transparency.  When seen from the front, the 'V' can be seen
> with the rest having transparency, but does not show up in the shadow.  On
> the other hand, when seen from behind, the 'V' can only be seen in the
> shadow and not on the cylinder.

[clip]

>  lathe{linear_spline 5,<40.001,0>,<40.001,100>,<40,100>,<40,0>,<40.001,0>}

Post a reply to this message