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Aminet 1 (Walnut Creek)
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Aminet - June 1993 [Walnut Creek].iso
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rayshade40_enh2.lha
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fracland.doc
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1992-07-12
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Syntax:
fracland [surface] "seed" "subdiv"
This primitive creates a fractal surface centered at x = 0.5, y = 0.5
and ranging from x = y = 0 to x = y = 1. It is actually a heightfield primitive
that is generated within rayshade rather than being read in from a file.
The "seed" value is the seed for the random number function. The seed
value specifies the shape of the surface -- changing the seed value will
randomly change the surface shape.
The "subdiv" value is the number of subdivisions for the surface --
subdiv = 0 will produce a flat square, subdiv > 0 will produce a square with an
ever more detailed surface. So far, rayshade seems to have trouble with
subdivisions greater than eight (if anyone finds otherwise please tell me!!)
and produces surfaces with "holes" in it for values greater than this.
The number of points in the surface follows the following formulas:
size (number of points per side) = (2^subdiv) + 1; total points = size^2.
The four corner points will always have an altitude of zero, the max
altitude should never be never be more 1.0 and the min should never be less
than -1.0.
Any bugs or comments can be sent to me at lcoffin@clciris.chem.umr.edu.
---Larry Coffin
lcoffin@clciris.chem.umr.edu