> Warp<war### [at] tagpovrayorg>  wrote:
>> W0RLDBUILDER<nomail@nomail>  wrote:
>>>> #declare Star = /* your star object here */;
>>>>
>>>> #declare Amount = 500;
>>>> #declare Seed = seed(0); // Try integer values other than 0 for other
>>>>                           // distributions
>>>> #declare MinExtent =<-100, -100, -100>;
>>>> #declare MaxExtent =<100, 100, 100>; // Modify as desired
>>>>
>>>> #declare Index = 0;
>>>> #while(Index<  Amount)
>>>>    object
>>>>    { Star
>>>>      #declare RandVector =<rand(Seed), rand(Seed), rand(Seed)>;
>>>>      translate MinExtent + (MaxExtent - MinExtent) * RandVector
>>>>    }
>>>>    #declare Index = Index + 1;
>>>> #end
>>>>
>>>> --
>>>>                                                            - Warp
>>
>>> Thanks. Would that work if I copy/pasted it several times for different types of
>>> stars?
>>
>>    Better to use a macro for that, like:
>>
>> #macro CreateStars(StarObject, Amount, Seed)
>>    #local MinExtent =<-100, -100, -100>;
>>    #local MaxExtent =<100, 100, 100>; // Modify as desired
>>
>>    #local Index = 0;
>>    #while(Index<  Amount)
>>      object
>>      { StarObject
>>        #declare RandVector =<rand(Seed), rand(Seed), rand(Seed)>;
>>        translate MinExtent + (MaxExtent - MinExtent) * RandVector
>>      }
>>      #local Index = Index + 1;
>>    #end
>> #end
>>
>> #declare Seed = seed(0);
>> CreateStars(Star1, 100, Seed)
>> CreateStars(Star2, 100, Seed)
>> CreateStars(Star3, 100, Seed)
>>
>> --
>>                                                            - Warp
>
> I can't get that to work. I know I'm doing something wrong here. It's probably
> not a good idea to drop a macro on top of a semi-n00bish casual user who just
> wants to place some random stars. :-P
>
>

You only need to copy the macro definition and the macro calls into your 
scene. Make sure that the calls are placed after the macro definition.

The only thing missing here, is the definitions for "Star1", "Star2" and 
"Star3".

You can:
- #declare all star objects before the calls to CreateStars()
- #declare the star objects before each individual call. In this case, 
you can reuse the same name.
- Define the star object inside the call itself.

In the lase case, you can use this:

CreateStars(sphere{0,0.1 pigment rgb<1,0.5,0.2>finish{ambient 1 diffuse 
0}}, 100, Seed)



Alain

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