// Exemplo de arquivo de descricao de cena para POV-ray
// Last edited on 2017-05-07 20:10:09 by stolfilocal

// ======================================================================
// CORES E TEXTURAS

background{ color rgb < 0.75, 0.80, 0.85 > }

#declare tx_plastico = 
  texture{
    pigment{ color rgb < 0.10, 0.80, 1.00 > }
    finish{ diffuse 0.8 ambient 0.1 specular 0.5 roughness 0.005 }
  }

#declare tx_fosca = 
  texture{
    pigment{ color rgb < 1.00, 0.80, 0.10 > }
    finish{ diffuse 0.9 ambient 0.1 }
  }

#declare tx_espelho = 
  texture{
    pigment{ color rgb < 1.00, 0.85, 0.30 > }
    finish{ diffuse 0.2 reflection 0.7*< 1.00, 0.85, 0.30 > ambient 0.1 }
  }

#declare tx_vidro = 
  texture{
    pigment{ color rgb < 0.85, 0.95, 1.00 > filter 0.70 }
    finish{ diffuse 0.03 reflection 0.25 ambient 0.02 specular 0.25 roughness 0.005 }
  }


#declare tx_xadrez =
  texture{
    pigment{ checker color rgb < 0.10, 0.32, 0.60 >, color rgb < 1.00, 0.97, 0.90 > }
    finish{ diffuse 0.9 ambient 0.1 }
    scale 2.0
  }

// ======================================================================
// DESCRIÇÃO DA CENA 

#macro CordaCirculo(raio, n)
	#declare i = 0;
	union {
		#while(i < n)
			object { sphere{ < raio*sin((2*3.1415*i)/n), 0, cos((2*3.1415*i)/n) >, 0.3} texture { tx_fosca }}	
			#declare i = i + 1;	
		#end
	}
#end

#macro CordaQuadrado(centro, lado, n)
	#declare i = 0;
	#declare tt = 0.0;
	union {
		#while(i < n)
			#if ((tt >= 0) & (tt < 0.25))
				#declare centro = < sin((2*pi*i)/n), 0, 0 >;
			#end
			#if ((tt >= 0.25) & (tt < 0.50))
				#declare centro = < 0, 0, cos((2*pi*i)/n) >;
			#end
			#if ((tt >= 0.5) & (tt < 0.75))
				#declare centro = < sin((2*pi*i)/n)+1, 0, -1 >;
			#end
			#if ((tt >= 0.75) & (tt < 1.00))
				#declare centro = < 1, 0, cos((2*pi*i)/n)-1 >;
			#end
			
			object { sphere{ lado*centro , 0.3} texture { tx_fosca }}

			#declare tt = tt + 1/(n);
			#declare i = i + 1;
		#end
	}
#end

#macro Corda(centro, lado, n)
	#declare i = 0;
	#declare tt = 0.0;
	union {
		#while(i < n)
			#if ((tt >= 0) & (tt < 0.125))
				#declare centro = < 0, 0, cos((2*pi*i)/n) >;
			#end
			#if ((tt >= 0.125) & (tt < 0.250))
				#declare centro = < sin((2*3.1415*i)/n) - 1, 0, cos((2*3.1415*i)/n) + 1 >;
			#end
			#if ((tt >= 0.250) & (tt < 0.375))
				#declare centro = < sin((2*pi*i)/n)-1.32, 0, 1.72 >;	
			#end
			
			object { sphere{ lado*centro , 0.2} texture { tx_fosca }}

			#declare tt = tt + 1/(n);
			#declare i = i + 1;
		#end
	}
#end

Corda(0, 2, 200)

#include "camlight.inc"
#declare centro_cena = < 0, -5, 2 >;
#declare raio_cena = 4.0;
#declare dir_camera = < -5.00, 20.00, 0.00 >;
#declare dist_camera = 5*raio_cena;
#declare intens_luz = 1.20;
camlight(centro_cena, raio_cena, dir_camera, dist_camera , z, intens_luz)