Hi Warp and Rick,

Thanks for your replies.
I guessed this is not trivial.  I'll give the area lights a try because of
the render time.

-C-H-A-R-L-E-S-

Warp <war### [at] tagpovrayorg> schrieb in im Newsbeitrag:
38fab709@news.povray.org...
> Charles <101### [at] germanynetde> wrote:
> : How can I build an array of equally ditributed point lights? They have
to be
> : on the surface of a sphere.
>
>   I don't think there's any way of doing this kind of thing in moray
(unless
> you make your own plugin).
>
> : Perhaps I would have a better chance in POV directly, but I havn't found
a
> : formula.
>
>   The problem of distributing points (approximately) evenly on the surface
> of a sphere is not trivial. Only certain amounts of points have an exact
> solution. Other amounts have to use only an approximation.
>   Usually an approximation is good enough. If so, you can use this
algorithm:
>
> #declare Spread = .1;
> #declare mintheta = 0;
> #declare maxtheta = pi;
>
> camera { location <-4,1,-6>*.7 look_at 0 angle 35 }
> light_source { <50,100,-200> 1 }
>
> #declare dtheta = atan2(Spread,1);
>
> #declare R=seed(0);
> #declare theta=mintheta;
> #while(theta<maxtheta)
>   #if(theta=0)
>     #declare dphi=2*pi;
>   #else
>     #declare dphi=dtheta/sin(theta);
>   #end
>   #declare minphi= -pi + dphi*rand(R)*.5;
>   #declare maxphi= pi - dphi/2 + (minphi+pi);
>   #declare phi=minphi;
>   #while(phi<maxphi)
>     sphere
>     { z,.05
>       rotate x*degrees(theta)
>       rotate z*degrees(phi)
>       pigment { rgb x } finish { specular .5 }
>     }
>     #declare phi=phi+dphi;
>   #end
>   #declare theta=theta+dtheta;
> #end
>
>
> --
> main(i,_){for(_?--i,main(i+2,"FhhQHFIJD|FQTITFN]zRFHhhTBFHhhTBFysdB"[i]
> ):5;i&&_>1;printf("%s",_-70?_&1?"[]":" ":(_=0,"\n")),_/=2);} /*- Warp -*/

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