3D Extruded Shamrock

on 17 Oct 2022

% 3D Extruded Shamrock

%T=linspace(0,2*pi,300);

T=0:.021:2*pi;

% Unit Wave function

g=@(f)(1-(abs(1-mod(T*3,2*pi)/pi)-.3).^2*2).*f(T);

% Convert into a polyshape, and then into a 3d object

t=@triangulation;

T=t(polyshape(g(@cos),g(@sin)));

P=T.Points;

F=T.ConnectivityList;

E=T.freeBoundary;

L=300;% size(P,1)

%R=1:size(E,1);

% The points used in the 3d triangulation are just the og points

% repeating, but at different Z levels. Use trick to fill in Z

% with 0 with no code at same time we fill half the Zs with 2.

j=[P

P];

j(1:L,3)=.3;% How tall to make the extrusion

% Use fcn handles to shorten edge magic.

% The wierd carriage returns/transpose trick saves 1 char per 3

% element array.

e=@(l,m)E(1:L,[l

2])+[0

L]';

% This is what the fcn handle replaces.

% E(R,[2 1 2])+[0 0 L];

% E(R,[1 1 2])+[0 L L]]

% Generate the final polygon as a triangulation.

V=t([F

F+L

e(2,0)

e(1,L)],j);

% Draw the 3d triangulation

trisurf(V);% ,-hypot(j(:,1),j(:,2))); % Using radial colors makes it

% look cool, but too many char.

shading interp

axis off equal

%colormap summer

camlight