//
// Author of this file: Oliver Labs
// Feb. 2003
// www.OliverLabs.net
//
// For the SuSE Title Pages Homepage:
// www.OliverLabs.net/suse/
//

int wid=300; width=wid; height=wid; 
antialiasing=6;

background_red=255; background_green=255; background_blue=255;

surface_red=102; surface_green=230; surface_blue=0;
inside_red=102; inside_green=230; inside_blue=0;

illumination = ambient_light + diffuse_light + reflected_light + transmitted_light;
ambient      = 40;
diffuse      = 80;
reflected    = 80;
transmitted  = 20;
smoothness   = 50;
transparence = 0;
thickness = 10;

light1_vol = 25;
light3_vol = 30;
light8_vol = 30;

perspective=central;
spec_z=14;

double sf=0.4; 
scale_x=sf; scale_y=sf; scale_z=sf;
radius=8;
rot_x=-0.0;
rot_y=-0.9;

// tacnode of type 0, if
// b<0 or (b>0 and a < 3-2sqrt(b))
// tacnode of type 1, if
// b>0 and 3-2sqrt(b) < a < 3+2sqrt(b)
// tacnode of type 2, if
// b>0 and 3+2sqrt(b) < a

double b=4; // => sqrt(b)=2
double a;
//a=-2; // type 0
//a=0; // type 1
a=8; // type 2

double a0=a;
double a1=a;
double a2=a;
double a3=a;
double a4=b;
double a5=b;

// set coordinates
poly xx=z-1+sqrt(2)*x;
poly yy=z-1-sqrt(2)*x;
poly zz=-(z+1+sqrt(2)*y);
poly ww=-(z+1-sqrt(2)*y);

surface=
(xx+zz)^2*(yy^3+ww^3) + 
(yy+ww)^2*(xx^3+zz^3) + 
(a0*yy*zz*ww + 
a1*xx*zz*ww + 
a2*xx*yy*ww + 
a3*xx*yy*zz)
*(yy+ww)*(xx+zz) 
+ 
a4*yy^2*ww^2*(xx+zz) +
a5*xx^2*zz^2*(yy+ww);
draw_surface;

color_file_format=jpg;
filename="pro_82.jpg";
save_color_image;