#include "functions.inc"
#include "colors.inc"  
#include "math.inc"

camera
{
	location < 0, 10, -10 >
	look_at < 0, 0, 0 >
} 
     
light_source { < 0, 10, 0 > color White }

#declare n = 5;

#declare fn_pattern = function( x, y, px, py )
{  
	cos( sqrt( ( ( x - px ) * ( x - px ) ) + ( ( y - py ) * ( y - py ) ) ) * n * 4 * pi )
}              

#declare fn_water = function ( x, y, px, py )
{                         
	fn_pattern( x, y, px, py ) * exp( -2 - ( 10 * ( ( ( x - px ) * ( x - px ) ) + ( ( y - py ) * ( y - py ) ) ) ) )
}

height_field
{
	function 500, 500 { fn_water( x, y, 0.5, 0.5 ) * 0.3 + 0.5 }
	smooth
	pigment { Cyan }
	translate < -0.5, -0.5, -0.5 >
	scale 10
}