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"Laurence M. Salme" wrote:
>
> I need help understanding how to use rand and seed. I figure a random of
> .75 to 1.0 may be needed for an image i'm working on.
Try these macros. For example to get a random number from 0.75 to 1 you'd have
to specify rand_ext(.875,.125,Seed) where Seed is a declares random number seed.
//Create random number of given mean and maximum deviation
//M - mean value
//D - maximum deviation
//Seed - (declared) random number seed identifier
#macro rand_ext(M,D,Seed)
(M+(rand(Seed)-.5)*2*D)
#end
//Give a random vector of given mean and max deviation
//M - mean (vector/float)
//D - max deviation (vector/float)
//Seed - (declared) random number seed identifier
#macro v_rand_ext(M,D,Seed)
#local MV=M+<0,0,0>;
#local DV=D+<0,0,0>;
(<rand_ext(MV.x,DV.x,Seed),rand_ext(MV.y,DV.y,Seed),rand_ext(MV.z,DV.z,Seed)>)
#end
--
Margus Ramst
Personal e-mail: mar### [at] peakeduee
TAG (Team Assistance Group) e-mail: mar### [at] tagpovrayorg
Home page http://www.hot.ee/margusrt
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