// 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 Yellow = rgb<255, 255, 0>;
#declare Black =  rgb < 0.4, 0.4, 0.4 >;

#declare tx_plastico = 
  texture{
    pigment{ color rgb < 0.4, 0.4, 0.4 > }
    finish{ diffuse 0.8 ambient 0.1 specular 0.5 roughness 0.005 }
  }
  
#declare esfera =
	sphere {
		< 0, 0,  0>, 0.25 // Near lower left corner
		 texture{ tx_plastico }
	}

#macro interpola(to, vo, t1, v1, tt )
	#local r = (tt-to)/(t1-to);
	#local s = 1-r;
	#local vv= s*vo+r*v1;
	vv
#end

#macro arcobezier(to, t1, a, b, c, d, tt )
	#local ab = interpola(to, a, t1, b, tt );
	#local bc = interpola(to, b, t1, c, tt );
	#local cd = interpola(to, c, t1, d, tt );	
	#local abc = interpola(to, ab, t1, bc, tt );
	#local bcd = interpola(to, bc, t1, cd, tt );
	#local abcd = interpola(to, abc, t1, bcd, tt );
	abcd
#end

#macro suavizaX(P,N,i)
 //Suaviza a junta entre o arco
 //i e o arco = mod(i+1,N)
#local j = mod(i+1,N);
#local vv = (P[j][i] - P[i][2])/2;
#declare P[i][2] = P[i][3]-vv;
#declare P[j][1] = P[j][0]+vv;
#end

#declare N = 3;
#declare P = array[N][4];

#declare P[0][0] = <0,-3,-2>;
#declare P[0][1] = <-5,-5,-4>;
#declare P[0][2] = <0,4,-2>;
#declare P[0][3] = <1,-1,4>;

#declare P[1][0] = <1,-1,4>;
#declare P[1][1] = <-2,-6,-2>;
#declare P[1][2] = <-2,2,0>;
#declare P[1][3] = <2,0,2>;

#declare P[2][0] = <2,0,2>;
#declare P[2][1] = <-5,-6,-1>;
#declare P[2][2] = <0,3,1>;
#declare P[2][3] = <0,-3,-2>;

suavizaX(P,2,0)
suavizaX(P,2,1)
suavizaX(P,2,2)

#declare Q = array[N][4];

#declare Q[0][0] = <4,0,-1>;
#declare Q[0][1] = <-1,-2,-2>;
#declare Q[0][2] = <4,6,-1>;
#declare Q[0][3] = <5,-5,2>;

#declare Q[1][0] = <5,-5,2>;
#declare Q[1][1] = <2,-1,-1>;
#declare Q[1][2] = <2,7,0>;
#declare Q[1][3] = <6,5,1>;

#declare Q[2][0] = <6,5,1>;
#declare Q[2][1] = <-1,-1,-0.5>;
#declare Q[2][2] = <4,8,0.5>;
#declare Q[2][3] = <4,2,-1>;

#macro noh(P,N,M)
#local t0 = 0;
#local t1 = M;
#local i = 0;
    
    union {
    #while(i<N)
        #local tt = t0;
        #while(tt<t1)
            object { esfera translate arcobezier(t0,t1,P[i][0],P[i][1],P[i][2],P[i][3],tt) }
            #local tt = tt+1;
        #end
        #local i = i +1;
    #end
    }
#end

#declare R = array[N][4];
#for(i,0,N-1,1)
    #for(j,0,3,1)
        #declare R[i][j] = <0,0,0>;
    #end
#end

#macro interpola1matriz(P,Q,N,c0,c1,cc,R)
    #local i = 0;
    #while(i<N)
        #local k = 0;
        #while(k<3)
            #declare R[i][k] = interpola(c0,P[i][k],c1,Q[i][k],cc);
            #local k = k+1;
        #local i = i + 1;
        #end
    #end
#end

#macro interpolamatrizes(P,Q,N)
    #for(cc,0,2,0.2)
        interpola1matriz(P,Q,N,0,1,cc,R)
        object { noh(R,N,300) }
    #end
#end

// ======================================================================
// DESCRICAO DA CENA 

#include "eixos.inc"

object{ eixos(3.00) }

interpolamatrizes(P,Q,3)

#include "camlight.inc"
#declare centro_cena = < 0.00, 0.00, 1.00 >;
#declare raio_cena = 8;
#declare dir_camera = < 14.00, 7.00, 4.00 >;
#declare dist_camera = 5*raio_cena;
#declare intens_luz = 1.20;
camlight(centro_cena, raio_cena, dir_camera, dist_camera , z, intens_luz)