To answer the question about random numbers, I would assume that due to
probabilitistic sampling, there SHOULD be more numbers around the center
(one or two deviations) than the edges.  BUT I assume you aren't getting
the results you want, so you could try a couple of things.  One, run the
randoms between -15 and 15 first, then another run out to the 30's... or
start with a random from like -2 to 2 and then slowly increase out to
the 30's...should distribute more centrally.

Steve


ingo wrote:
> 
> Hi,
> I'm trying to make randomly curled paper sheets, I have two questions on
> this:
> 1. Although I don't need mutch detail I'd like to smooth the paper, so how
> to calculate the normals for smooth triangles?
> 2. How do I generate random numbers between -30 and +30, in such a way that
> there are mutch more between -15 and 15 than between -30 and 30?
> 
> ingo
> 
> #version 3.1;
> #include "colors.inc"
> global_settings{assumed_gamma 1.0}
> 
> light_source{
>   <500,500,-500>
>   color rgb 1
> }
> camera{
>     location<0.0,0.0,-2.5>
>     look_at<0.0,0.0,0.0>
> }
> //  #declare Rnd ......
> #declare A=vrotate(vaxis_rotate(<-0.25,0.25,
> 0>,<1,1,0>,Rnd)+<-0.25,0.25,0>,<Rnd,Rnd,0>);
> #declare B=vrotate(<0,0.5,0>,<Rnd,0,0>);
> #declare C=vrotate(vaxis_rotate(<0.25,0.25, 0>,<1,-1, 0>,Rnd)
> +<0.25,0.25,0>,<Rnd,Rnd,0>);
> #declare D=vrotate(<-0.5,0,0>,<0,Rnd,0>);
> #declare E=<0,0,0>;
> #declare F=vrotate(<0.5,0,0>,<0,Rnd,0>);
> #declare G=vrotate(vaxis_rotate(<-0.25,-0.25,0>,<-1,1,0>,Rnd)
> +<-0.25,-0.25,0>,<Rnd,Rnd,0>);
> #declare H=vrotate(<0,-0.5,0>,<Rnd,0,0>);
> #declare I=vrotate(vaxis_rotate(<0.25,-0.25,0>,<-1,-1,0>,Rnd)
> +<0.25,-0.25,0>,<Rnd,Rnd,0>);
> 
> mesh {
>   triangle {A,B,D}
>   triangle {D,B,E}
>   triangle {E,B,F}
>   triangle {B,C,F}
>   triangle {D,G,H}
>   triangle {D,H,E}
>   triangle {E,H,F}
>   triangle {H,I,F}
>   scale <1,2,1>
>   pigment {rgb 1}
> }
> 
> ---
> Thank, to the Muse with the glass eye.

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