size(200); import palette; import three; currentprojection=orthographic(1,1,1); triple[] M={ (-1,-1,-1),(0,-1,-1),(1,-1,-1),(1,0,-1), (1,1,-1),(0,1,-1),(-1,1,-1),(-1,0,-1), (-1,-1,0),(1,-1,0),(1,1,0),(-1,1,0), (-1,-1,1),(0,-1,1),(1,-1,1),(1,0,1),(1,1,1),(0,1,1),(-1,1,1),(-1,0,1) }; surface[] Squares={ surface((1,-1,-1)--(1,1,-1)--(1,1,1)--(1,-1,1)--cycle), surface((-1,-1,-1)--(-1,1,-1)--(-1,1,1)--(-1,-1,1)--cycle), surface((1,1,-1)--(-1,1,-1)--(-1,1,1)--(1,1,1)--cycle), surface((1,-1,-1)--(-1,-1,-1)--(-1,-1,1)--(1,-1,1)--cycle), surface((1,-1,1)--(1,1,1)--(-1,1,1)--(-1,-1,1)--cycle), surface((1,-1,-1)--(1,1,-1)--(-1,1,-1)--(-1,-1,-1)--cycle), }; int[][] SquaresPoints={ {2,3,4,10,16,15,14,9}, {0,7,6,11,18,19,12,8}, {4,5,6,11,18,17,16,10}, {2,1,0,8,12,13,14,9}, {12,13,14,15,16,17,18,19}, {0,1,2,3,4,5,6,7} }; int[][] index={ {0,2,4},{0,1},{1,2,4},{2,3},{1,3,4},{0,1},{0,3,4},{2,3}, {4,5},{4,5},{4,5},{4,5}, {0,2,5},{0,1},{1,2,5},{2,3},{1,3,5},{0,1},{0,3,5},{2,3} }; int[] Sponge0=array(n=6,value=1); int[] eraseFaces(int n, int[] Sponge0) { int[] temp=copy(Sponge0); for(int k : index[n]) { temp[k]=0; } return temp; } int[][] Sponge1=new int[20][]; for(int n=0; n < 20; ++n) { Sponge1[n]=eraseFaces(n,Sponge0); } int[][] eraseFaces(int n, int[][] Sponge1) { int[][] temp=copy(Sponge1); for(int k : index[n]) for(int n1 : SquaresPoints[k]) temp[n1][k]=0; return temp; } int[][][] Sponge2=new int[20][][]; for(int n=0; n < 20; ++n) Sponge2[n]=eraseFaces(n,Sponge1); int[][][] eraseFaces(int n, int[][][] Sponge2) { int[][][] temp=copy(Sponge2); for(int k : index[n]) for(int n2: SquaresPoints[k]) for(int n1: SquaresPoints[k]) temp[n2][n1][k]=0; return temp; } int[][][][] Sponge3=new int[20][][][]; for(int n=0; n < 20; ++n) Sponge3[n]=eraseFaces(n,Sponge2); surface s3; real u=2/3; for(int n3=0; n3 < 20; ++n3) { surface s2; for(int n2=0; n2 < 20; ++n2) { surface s1; for(int n1=0; n1 < 20; ++n1) { for(int k=0; k < 6; ++k) { if(Sponge3[n3][n2][n1][k] > 0) { s1.append(scale3(u)*shift(M[n1])*scale3(0.5)*Squares[k]); } } } s2.append(scale3(u)*shift(M[n2])*scale3(0.5)*s1); } s3.append(scale3(u)*shift(M[n3])*scale3(0.5)*s2); } s3.colors(palette(s3.map(abs),Rainbow())); draw(s3);