#include "colors.inc"
#include "shapes.inc"
#include "math.inc"
global_settings
{
ambient_light rgb .2*<1, 1, 1>              // background light
// used in global_settings, sets image gamma in relation to display gamma
  assumed_gamma 1.0
}
background {color rgb <.7, .7, .7>}             
#declare c=1;      //speed of waves
#declare Lx=1;     //dimensions of box
#declare Ly=1;
#declare nx=2;     //order of mode
#declare ny=1;
#declare amp=.2*cos(2*pi*clock);
#declare factorial = function(C) { prod(i, 1, C, i) }
#declare Jbes = function(m,xx) { pow(xx/2,m)*
                (1/factorial(m)+sum(r,1,16, pow(-1,r)/(factorial(r)*factorial(m+r))*pow(xx/2,m))
                )}

isosurface {
        function {
        
                amp*sin(nx*pi*x/Lx)*sin(ny*pi*z/Ly)-y
               
                }   // isosurface y =  sum of terms above
                
          open                             // don't include bounding box in shape
          contained_by  {box{-1.2*y,x+z+1.2*y}}        // dimensions of the bounding box
        max_gradient 5
          accuracy      0.001              // accuracy of calc for surface rendering

                  texture {
  pigment {          // (---surface color---)
 Blue  }
/*  normal {           // (---surface bumpiness---)
    marble 0.3       // some pattern (and intensity)
    turbulence 0.5   // some turbulence
    scale 55*<1,3,1>    // transformations
  }*/
  finish {           // (---surface finish---)
    ambient 0.2
    specular 0.6     // shiny
    phong .2
  }
}

         
}
/* camera is far away with narrow FOV to reduce distortion */
camera {
    location 3*<-.2, .2 ,-1>
    look_at  <.5, 0, .5>
    angle 20
}
// An area light (creates soft shadows)
// WARNING: This special light can significantly slow down rendering times!
light_source {
  0*x                 // light's position (translated below)
  color rgb 1.0       // light's color
  area_light
  <2, 0, 0> <0, 0, 2> // lights spread out across this distance (x * z)
  4, 4                // total number of lights in grid (4x*4z = 16 lights)
  adaptive 0          // 0,1,2,3...
  jitter              // adds random softening of light
  circular            // make the shape of the light circular
  orient              // orient light
  translate <0, 20, -4>   // <x y z> position of light
}
// create a regular point light source
light_source {
  0*x                  // light's position (translated below)
  color rgb <.5,.5,1>    // light's color
  translate 5*<-0, -40, -20>
}

#declare rim=.005;
cylinder { <0, 0, 0>, x*Lx, rim }
cylinder {  x*Lx, x*Lx+z*Ly, rim }
cylinder { x*Lx+z*Ly, z*Ly, rim }
cylinder { <0, 0, 0>, z*Ly, rim }