// -----------------------------------------------------------------------------
// 2024-05-04
// -----------------------------------------------------------------------------
#version 3.8;



// -----------------------------------------------------------------------------
// --- INCLUDES ----------------------------------------------------------------
// -----------------------------------------------------------------------------
#include "colors"
#include "math"





// -----------------------------------------------------------------------------
// --- SETTINGS ----------------------------------------------------------------
// -----------------------------------------------------------------------------
global_settings {
	assumed_gamma 1.00
//	max_trace_level 5 
	}

#default {
	finish {
		ambient 0.00
		emission 0.40
		diffuse 0.60
		}
	} 


// -----------------------------------------------------------------------------
// --- SCENE -------------------------------------------------------------------
// -----------------------------------------------------------------------------
camera {
	location <25, 8, 15>
	up y
	right x*image_width/image_height
	look_at <0, 0, 0>
	angle 36
	}

light_source {
	<375, 250, 220>
	color White
	}

//sky_sphere {
//	pigment {
//		function { abs(y) }
//		color_map {
//			[0.0 color Navy ]
//			[1.0 color White ]
//			}
//		}
//	}

background { White*0.50 }



// -----------------------------------------------------------------------------
// --- OBJETS ------------------------------------------------------------------
// -----------------------------------------------------------------------------
//sphere { <0,0,0>, 9 
//	pigment { rgbt <1,1,0,0.80> }
//	}

#declare sq = function(a) { a*a };

isosurface {
	function {
		(sq(sqrt(x*x + y*y) - 3) + z*z - 0.4 ) *
		(sq(sqrt((x - 4.5)*(x - 4.5) + z*z) - 3) + y*y - 0.4) *
		(sq(sqrt((x + 4.5)*(x + 4.5) + z*z) - 3) + y*y - 0.4) *
		(sq(sqrt((y + 4.5)*(y + 4.5) + z*z) - 3) + x*x - 0.4) *
		(sq(sqrt((y - 4.5)*(y - 4.5) + z*z) - 3) + x*x - 0.4) *
		(sq(sqrt(x*x + y*y) - 5) + z*z - 0.4 )
		} 
	contained_by { sphere { <0,0,0>, 9 } }

//   threshold 0
//   accuracy 0.0005

	max_gradient 2e10 // 4e6 // 3e10

	pigment { color CoolCopper }
//	finish { phong 0.5 phong_size 10}
	}



// --- eof ---------------------------------------------------------------------