Thanks for the info! I'm trying to find out how to create random numbers
between -0.75 and 0.75. I tried to come up with the function using your
examples but I can't seem to get it right. The general for seems to be

Num = rand*x + y

so

-0.75 = 0.1*x +y and
0.75 = 0.9*x +y

I've tried solving for x and y, buy graphing and calculating the
intersection of the 2 lines, but this doesn't work.


"Dave Blandston" <gra### [at] earthlinknet> wrote in message
news:3afdcfd6@news.povray.org...
> Random numbers are lots of fun. Generally, you need to multiply the random
> number by some amount and then add or subtract a constant in order to get
> random numbers within the range that you want. For example, if you want
real
> random numbers between 20 and 25, you could do this:
>     #local NewZ = rand (MySeed) * 5 + 20;
>
> If you want integer random numbers between -3 and 3, you could do this:
>     #local NewZ = int (rand (MySeed) * 7) - 3;
>
> Here's one more example: To get numbers between .2 and .3, you could use
> this:
>     #local NewZ = rand (MySeed) * .1 + .2;
>
> Have fun,
> Dave Blandston
> --------------------------------------
>
> "Thomas Lake" <tla### [at] homecom> wrote in message
> news:3afdcb2e$1@news.povray.org...
> > In my previous post I talked about adding random translation/rotation
into
> > my tunnel building script. I've played around with the rand() function
> with
> > mixed results. From what I understand it works like so
> >
> > #declare myseed = seed(12);
> >
> > translate <0,0,rand(myseed)>
> >
> > The problem with this is that the random value you get is only between 0
> and
> > 1. SO I tried the following.
> >
> > translate <0,0,rand(myseed)/rand(myseed)> or
> > translate <0,0,rand(myseed)/rand(myseed)*rand(myseed)>
> >
> > This does work better but I still don't get the effect I want. With this
> > method most of the objects are still only translated an imperceptible
> > amount, and then every once in a while an object will be translated a
> large
> > distance. What I want is for all the objects to be noticeably translated
a
> > random amount, but I don't want any sudden leaps.
> >
> >
>
>

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