// 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 < 0.20, 0.40, 0.60 > }

#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_alt = 
  texture{
    pigment{ color rgb < 0.10, 0.40, 0.20 > transmit 0.91 }
    finish{ diffuse 0.8 ambient 0.1 specular 0.5 roughness 0.005 }
  }

#declare tx_alt2 = 
  texture{
    pigment{ color rgb < 0.70, 0.40, 0.50 > transmit 0.81 }
    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 < 0.50, 0.32, 0.60 >, color rgb < 1.00, 0.97, 0.90 > }
    finish{ diffuse 0.9 ambient 0.1 }
    scale 3.0
  }

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

#declare raio = 1.500;

// Partes da cena:

#declare N = 100;

#declare f = 0;
#declare g = 0;

#declare R = array[4][4];
#while(f<4)
  #while(g<4)
    #declare R[f][g] = <0,0,0>;
    #declare g = g+1;
  #end
  #declare f = f+1;
#end

#macro interpola(t0,u0,t1,u1,tt)
  #local r = (tt-t0)/(t1-t0);
  #local s = 1-r;
  #local uu = s*u0 +r*u1;
  uu
#end

#macro arcobezier(t0,t1,A,B,C,D,tt)
  #local AB = interpola(t0,A,t1,B,t0);
  #local BC = interpola(t0,B,t1,C,tt);
  #local CD = interpola(t0,C,t1,D,tt);

  #local ABC = interpola(t0,AB,t1,BC,tt);
  #local BCD = interpola(t0,BC,t1,CD,tt);
  
  #local ABCD = interpola(t0,ABC,t1,BCD,tt);
  ABCD
#end

#macro arco (n,t0,t1,a,b,c,d)
  #local i = 0;
  #local tt = 0;
  #while (i < n)
    #local centro = arcobezier(t0, t1, a, b, c, d, tt);
    sphere {
      centro, 0.3
      texture {tx_alt2}
    }
    #local tt = tt + 1/n;
    #local i = i +1;
  #end
  
#end

#declare P = array[4][4] {
  {<0,0,0>,  <5, 0, 5>, <2.5, 0, 2.5>, <2.5, 0, 5>},
  {<0,0,0>,  <-2.5, 0, -2.5>, <-4.5, 0, -5>, <-2.5, -1, -6>},
  {<2.5,0,5>,  <1, 2.5, 2.5>, <1.5, 3.5, 1.5>, <1.5, 1.5, 0>},
  {<-2.5,-1,-6>,  <2.5, -1, -2>, <3.5, -1, 0>, <1.5, 1.5, 0>}
  };

#declare Q = array[4][4] {
  {<-5,0,0>,  <5, 0, 5>, <2.5, 0, 2.5>, <2.5, 10, 5>},
  {<-5,0,0>,  <-2.5, 5, -2.5>, <-4.5, 0, -5>, <-6, -1, -4>},
  {<2.5,10,5>,  <1, 2.5, 2.5>, <1.5, 3.5, 1.5>, <1.5, 1.5, 0>},
  {<-6,-1,-4>,  <2.5, -1, -2>, <3.5, -1, 0>, <1.5, 1.5, 0>}
  };

#macro suaviza(P,n,i)
  #local j = mod(i+1,n);
  #local uu = (P[j][1] - P[i][2])/2;
  #declare P[i][2] = P[i][3] - uu;
  #declare P[j][1] = P[j][0] + uu;
#end

//P = matriz dos pontos, n = numero de arcos, m = numero de bolinhas que compoem
//uma curva
//arco (n,t0,t1,a,b,c,d)
#macro noh(P,n,m)
  #local i = 0;
  #while (i < n)
    arco(m,0,1,P[i][0],P[i][1],P[i][2],P[i][3])
    #local i = i+1;
  #end

#end

//N = numero de linhas da matriz
//Define cada elemento R[i][k]
//interpolando linearmente P[i][k]
//e Q[i][k], para cc entre c0 e c1
#macro interpola1matriz(P,Q,X,c0,c1,cc,R)
  #local i=0;
  #while(i < X)
    #local k = 0;    
    #while(k < 4)
      #declare R[i][k]=interpola(c0,P[i][k],c1,Q[i][k],cc);
      #local k = k+1;
    #end
    #local i = i+1;
  #end

#end
  
#include "eixos.inc"

// Aqui está a cena, finalmente:
object { eixos(4.00) }

#local i = 0;  
#while (i<4)
  suaviza(Q, 3, i)  
  #local i = i +1;
#end


#local dd= 0;
#while(dd <= 1)
  interpola1matriz(P,Q,4,0,1,dd,R)
  noh(R,4,N)
  #local dd = dd+0.25;
#end

#include "camlight.inc"
#declare centro_cena = < 0.00, 0.00, 1.00 >;
#declare raio_cena = 20.0;
#declare dir_camera = < 7.00, 2.00, 4.00 >;
#declare dist_camera = 4*raio_cena;
#declare intens_luz = 1.20;
camlight(centro_cena, raio_cena, dir_camera, dist_camera , z, intens_luz)

  //object {chao translate <0,0,-6> texture {tx_xadrez}}
  //sphere{<0,0,0>, 0.6 texture{tx_alt}}
  //sphere{<5,0,5>, 0.6 texture{tx_alt}}
  //sphere{<2.5,0,2.5>, 0.6 texture{tx_alt}}
  //sphere{<2.5,0,5>, 0.6 texture{tx_alt}}
  
  //sphere{<0,0,0>, 0.3 texture{tx_plastico}}
  //sphere{<-2.5,0,-2.5>, 0.3 texture{tx_plastico}}
  //sphere{<-4.5,0,-5>, 0.3 texture{tx_plastico}}
  //sphere{<-2.5,0,-6>, 0.3 texture{tx_plastico}}
  
  //sphere{<2.5,0,5>, 0.6 texture{tx_xadrez}}
  //sphere{<1,2.5,2.5>, 0.6 texture{tx_xadrez}}
  //sphere{<1.5,3.5,1.5>, 0.6 texture{tx_xadrez}}
  //sphere{<1.5,1.5,0>, 0.6 texture{tx_xadrez}}

  //sphere{<-2.5,0,-6>, 0.6 texture{tx_alt2}}
  //sphere{<2.5,-1,-2>, 0.6 texture{tx_alt2}}
  //sphere{<3.5,-1,0>, 0.6 texture{tx_alt2}}
  //sphere{<1.5,1.5,0>, 0.6 texture{tx_alt2}}