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Polyhedron Stellation



Dodecahedron Stellation

Facet Diagram


DodecahedronStellationFacetMap.pdf

MATLAB code

The images shown in the right column are renderd in SunFlow.The MATLAB code given below will generate a different image ,without highlighting the edge.

function dodecahedronStellation
phi=(1+sqrt(5))/2;
vert=[1 1 1
     1 1 -1
     1 -1 1
    1 -1 -1
    -1 1 1
    -1 1 -1
    -1 -1 1
    -1 -1 -1
    0 1/phi phi
    0 1/phi -phi
    0 -1/phi phi
    0 -1/phi -phi
    1/phi phi 0
    1/phi -phi 0
    -1/phi phi 0
    -1/phi -phi 0
    phi 0 1/phi
    phi 0 -1/phi
    -phi 0 1/phi
    -phi 0 -1/phi];
            
faces=[1 13 2 18 17;
       1 9 5 15 13;
       13 15 6 10 2;
       2 10 12 4 18;
       18 17 3 14 4;
       1 9 11 3 17;
       5 9 11 7 19;
       15 5 19 20 6;
       6 20 8 12 10;
       20 19 7 16 8;
       8 12 4 14 16;
       11 7 16 14 3];

%great dodecahedron   
facetIndex=[5 3 4
            8 4 12
            11 12 13
            10 13 7
            6 7 3]';
        
%small stellated dodecahedron
% facetIndex=[5 4 8;
%             8 12 11
%             11 13 10
%             10 7 6
%             6 3 5]';
        
%great stellated dodecahedron
% facetIndex=[4 9 12
%             12 15 13
%             13 14 7
%             7 2 3
%             3 1 4]';
        
r=[7.2068;7.2068;2.7528;2.7528;1.0515;1.0515;2.7528;1.0515;
   7.2068;1.0515;1.0515;2.7528;2.7528;7.2068;7.2068];

theta=[2.8274;-2.1991;-2.8274;2.1991;2.8274;-2.1991;-1.5708;1.5708;
        1.5708;-0.94248;0.31416;0.94248;-0.31416;-0.94248;0.31416];

for n=1:length(faces)
   
    v=vert(faces(n,:),:);
    center=mean(v);%center of each face
 
    R=v(1,:)-center;
    R=R/sqrt(sum(R.^2));
    S=cross(R,center);
    S=S/sqrt(sum(S.^2));
    
    faceTheta=theta(facetIndex(:))-deg2rad(18);
    faceR=r(facetIndex(:));
 
    qx=center(1)+faceR.*cos(faceTheta).*R(1)+faceR.*sin(faceTheta).*S(1);
    qy=center(2)+faceR.*cos(faceTheta).*R(2)+faceR.*sin(faceTheta).*S(2);
    qz=center(3)+faceR.*cos(faceTheta).*R(3)+faceR.*sin(faceTheta).*S(3);
    
    patch('vertices',[qx qy qz],...
          'faces',[1 2 3;4 5 6;7 8 9;10 11 12;13 14 15],...
          'facecolor','c');

 
end

%patch('vertices',vert,'faces',faces,'facecolor','none');
view(3)
set(gcf,'renderer','zbuffer');
axis equal


Great Dodecahedron


Small Stellated Dodecahedron


Great Stellated Dodecahedron