JLH wrote:
> Thorsten Froehlich <tho### [at] trfde> wrote:
>> JLH wrote:
>>> Here are two questions that are connected:
>>> 1. In the POVRAY coordinate system at least one function is sensitive to the
>>> direction "North" and that is "sunpos". Is North in the z-direction by
>>> default?
>> There is no such thing as "North" in POV-Ray. What are you talking about?
>>
>>  Thorsten
> 
> "sunpos" requires an input of h:m:s, lat long, to provide the correct
> direction of the sun's light. This requires an implicit assumption of the
> direction of the N-S meridian. I was wanting to find out if this was the
> z-axis. Since then I have found in the help files that the N-S line is
> indeed the z axis. Now I just wonder at the answer to the second
> question-can one do global rotations of whole scenes? I suspect the answer
> is no. JLH

Well, the "sunpos" you seem to be talking about is nothing more than a
macro, so you can (a) see how it is implemented by checking "sunpos.inc" and
(b) it only returns a location vector. Consequently, there is little use to
rotate the whole scene to match to a light source which is *also* part of
that scene (nothing would change).

In short, what you want to do is translate the light source, not the scene.
As you can have as many consecutive translations as you want, this is
trivial to do.

	Thorsten

Post a reply to this message