hi,

The problem is as follows:

in the 1st version, where you declare the object first and rotate "within"
the declare statement, it DOES rotate. But what you really want, is to have
it rotate randomly (?). This, it doesn't. It rotates around a fixed angle
defined by the first (and only) time you use Rrand().

in the 2nd version the angle is calculated EACH time the while loop reaches
Rrand(), and therefore the objects rotate around different angles.

So, yes, what you see is perfectly correct :-).

Hoping to be of help,

JWV


"N Shomber" <nsh### [at] hotmailcom> wrote in message
news:41225b60$1@news.povray.org...
> Hi,
>
> I was working on creating a scene for POV-Comp using POV-Ray
> 3.6.1.icl8.win32 and came across this interesting behavior.
>
> I am trying to declare an object that is rotated at some random angle
around
> an axis.  I need to create many of them so I declared a single instance
> first then used a #while loop to create all of them.
>
> I've found that if I include my rotate in the declaration, it doesn't make
> it to the final object for some reason, but if I include it in the while
> object declaration, it does.  Is this what's supposed to happen?
>
> Sample code:
>
> #declare R1=seed(0);
>
> camera{
>  location <0,00,-3>
>  look_at <0,0,0>
> }
>
> #declare pole=
>  cylinder{
>   <0,0,0>,<0,1,0>,.01
>   rotate <0,0,rand(R1)*360>
>   pigment{
>    rgb 1
>   }
>   finish{
>    ambient 1
>   }
>  }
> ;
>
> #declare c=100;
> #while (c>0)
>  object{
>   pole
>   translate <-1,0,0>
>  }
>  #declare c=c-1;
> #end
>
> #declare c=100;
> #while (c>0)
>  object{pole
>   rotate <0,0,rand(R1)*360>
>   translate <1,0,0>
>  }
>  #declare c=c-1;
> #end
>
>

Post a reply to this message