en ce 2008/04/19 08:21 :)   ->
> Hi,
> Thanks for all the nice suggestions.
> 
>> Just start with evenly spaced points in an array. Now, apply some vturbulence to
>> each point.
>> Now that your points are shifted from ther original locations, just use loops to
>> place and connect them. Your objects will be moved on all 3 axis from ther
>> original locations.
> 
> I think the turbulence option fits my need the best. But I'm not quite there
> yet. Hers my preliminary code:
> 
>
> ############################################################################
> 
> Maybe I don't get the parameters for vturbulence because I can't get the surface
> to be random at larger distances while being less random at shorter distances.
> 
> Any thoughts?
> 
> 
> 
> 
> 
> 
Try this:
      #declare A = <X,R,Z> + 1.5*vturbulence(1.5, 0.45, 2,<X/5,R,Z/5>)*<0,1,0>;

The first argument (lambda) determine the randommness of the steps. Usual values 
range from 1 to 2. Small values mean that the steps tend to be in the same 
direction. Large values mean that the direction of a step depends less on the 
direction of the preceding setp. Float larged than zero.

The second argument (omega) determine the relative weight of a step compared to 
the preceding one. Start with 0.5. Reduce for a smoother result. Float larger 
than zero up to 1.

The third argument (octaves) determine how many steps are used to perturb the 
positions. Increase to get more small scale perturbation. Integer values only.

By dividine X and Z by 5, I effectively spreaded the perturbations, equivalent 
to scaling the pattern by 5 horizontaly.

Now, it makes smooth, irregular, ondulations.

Unless you use all those includes elsewhere, you realy only use colors.inc. You 
can remove all other includes.

-- 
Alain
-------------------------------------------------
You know you've been raytracing too long when you've gained twenty pounds 
sitting at the computer, but can't tell because your beard covers your stomach.
Taps a.k.a. Tapio Vocadlo

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