Geometric object definded in my
include file "shapes3.inc"
(formerly "shapes_lo.inc").
Facetted_Egg
general syntax:
object{ Facetted_Egg(
Quarter_Meridian_Segments,
Equatorial_Segments
) //------------------------
texture{ ... ... }
} // end of object -----------
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Facetted_Egg_Shape
general syntax:
object{ Facetted_Egg_Shape(
Quarter_Meridian_Segments,
Equatorial_Segments,
Lower_Scale, Upper_Scale
) //-----------------------
texture{ ... ... }
} // end of object ----------- |
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Quarter_Meridian_Segments = number of segments in one quarter of a meridian,
Equatorial_Segments = number of segments along the equator and
Lower_Scale = y scale of the lower half of the shape,
Upper_Scale = y scale of the upper half of the shape.
The total height of these shapes is scaled to 2 units.
Examples:
#include "shapes3.inc"
object{ Facetted_Egg (6, 12 )
texture{ pigment{ color rgb<1,1,1>}
finish { phong 0.1}
}
scale 1 rotate<0,10,0>
translate<0,1.15,0>
} // end of object -----------------------
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#include "shapes3.inc"
object{ Facetted_Egg_Shape (9, 22, 1.85, 0.80)
texture{ pigment {color rgb<1,1,1>*1.3}
finish { phong 0.1}
}
scale 1 rotate<0,10,0>
translate<0,1.85,0>
} // end of object ----------------------- |
Macro in detail
This macro is realisized by an intersection of prisms with faccetted egg shape outline at one end:
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Facetted_Sphere - 1 prism element of the intersection
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Facetted_Sphere (6, 12 ) = intersection of 12 prisms
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//------------------------ macro Facetted_Egg_Shape()
#macro Facetted_Egg_Shape( Quarter_Segments,
Radial_Segments,
Lower_Scale,
Upper_Scale
) //-----------------------
#local Facets_Silhouette =
union{
prism {
-2 ,2 , Quarter_Segments +3
< -2,-1.00>,
#local Nr = -Quarter_Segments;
#local EndNr = 0;
#while (Nr < EndNr+1)
#local Angle_degrees = Nr* 90/Quarter_Segments;
#local Angle_radians = radians(Angle_degrees);
< cos (Angle_radians) , sin (Angle_radians)> ,
#local Nr = Nr + 1 ;
#end
< -2, 0>
//turns prism in z direction:
rotate <-90,0,0> scale <1,1,-1>
scale <1,Lower_Scale,1>
} // end of prism object --------------------------
prism {
-2 ,2 , Quarter_Segments+4
< -2, 0>,
#local Nr = 0;
#local EndNr = Quarter_Segments;
#while (Nr < EndNr+1)
#local Angle_degrees = Nr* 90/Quarter_Segments;
#local Angle_radians = radians(Angle_degrees);
< cos (Angle_radians) , sin (Angle_radians)> ,
#local Nr = Nr + 1 ;
#end
< -2, 1>,
< -2, 0>
//turns prism in z direction:
rotate <-90,0,0> scale <1,1,-1>
scal e<1,Upper_Scale,1>
} // end of prism object -----------------------
}// end of union
intersection{
#local Nr = 0; // start
#local EndNr = Radial_Segments; // end
#while (Nr < EndNr)
object{ Facets_Silhouette rotate <0,Nr * 360/EndNr,0>}
#local Nr = Nr + 1; // next Nr
#end // --------------- end of loop
} // end of intersection
#end // --------- end of macro Facetted_Egg_Shape() |
The macro Facetted_Egg() is realisized by the same macro with fixed Lower_Scale = 1.15 and Upper_Scale = 1.55:
// ------------------------------------------------- macro Facetted_Egg()
#macro Facetted_Egg(N_Quarter_Segments, N_Radial_Segments)
object{ Facetted_Egg_Shape(N_Quarter_Segments,N_Radial_Segments,1.15,1.55)
translate < 0, 1.15, 0>
scale 2/(1.15 + 1.55)
} //---------------------
#end // -------------------------------------- end of macro Facetted_Egg() |
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