// Dandelion Clock in Sunshine - SCC4 entry
// Verbose version
// Pete Hurst 13th Oct 2006 
background{.5+z/3} // Light blue background, would have preferred a sky_sphere...
disc{.8,z.7pigment{rgb 2-z}} // Yellow disc facing the viewer positioned in top-right of scene
                             // to look like edge of the Sun. Overbright colour fits in with
                             // tone of scene and produces interesting shading when light source
                             // is close. Admittedly the Sun shouldn't be this big at all but...
                             // artistic license?        
                             
// Main head of flower positioned at <0,0,1>                             
sphere{z.3hollow pigment{rgbt 1}

// Emissive media interior with high samples as density variation is very complex
interior{media{emission 2samples 999density{
// Function measures angles of coordinate and repeats by multiplying the angle (by
// frequency of repetition) and passing back through sin function. Offset z coord by -1 to
// account for position of flower. Slight turbulence applied to look like wind. Function only
// returns values greater than 0 otherwise to create gaps between the strands. Default color
// map rgb 0 -> rgb 1 is used.
function{max(0,sin(atan2(x,y)*48)*sin(atan2(x,z-1)*48))}turbulence.1}}}}

// Green cone running from centre of flower to outside viewport to look like a stalk.
cone{z,0,x/6-2*y+4*z,.1pigment{rgb y}}

// Very bright yellow light source cunningly positioned to shade and illuminate the Sun disc, as
// well as the side of the stalk farthest from the viewer, to create illusion of correct lighting
// from the Sun.
light_source{.4+z/6,2-z}