Crown in OpenSCAD

crown.png

crown.scad

// http://3dtoday.ru/questions/vopros-po-modelirovaniyu/

$fn=256;

outer_radius=10;
inner_radius=7.5;
center_height=10;
half_tooth_height=5;
number_of_teeth=4;

// Vertical position of the top surface point depending on it's polar coordinates
function curve(rr,tt) = center_height+half_tooth_height*cos(tt*number_of_teeth)*(rr/outer_radius);

function points(tt) = [for (aa=[0:360/$fn:360-.001]) [
    tt*sin(aa),
    tt*cos(aa),
    curve(tt,aa)
]];

function zero_z(points) = [for (ii=[0:len(points)-1]) [points[ii].x,points[ii].y,0]];

outerpoints=points(outer_radius);
innerpoints=points(inner_radius);

outertoppoints=outerpoints;
outerbottompoints=zero_z(outerpoints);
innertoppoints=innerpoints;
innerbottompoints=zero_z(innerpoints);

allpoints=concat(outerbottompoints,outertoppoints,innerbottompoints,innertoppoints);

outerfaces=[for (ii=[0:$fn-1]) [ii,(ii+1)%$fn,$fn+(ii+1)%$fn,$fn+ii]];
innerfaces=[for (ii=[0:$fn-1]) [2*$fn+ii,2*$fn+(ii+1)%$fn,3*$fn+(ii+1)%$fn,3*$fn+ii]];
bottomface=[concat([for (ii=[0:$fn]) 2*$fn+ii%$fn],[for (ii=[$fn:-1:0]) ii%$fn])];
topfaces1=[for (ii=[0:$fn-1]) [3*$fn+ii,$fn+ii,$fn+(ii+1)%$fn]];
topfaces2=[for (ii=[0:$fn-1]) [$fn+(ii+1)%$fn,3*$fn+(ii+1)%$fn,3*$fn+ii]];

allfaces=concat(outerfaces,innerfaces,bottomface,topfaces1,topfaces2);

polyhedron(points=allpoints,faces=allfaces);

CrownInOpenSCAD.md

Crown in OpenSCAD, see http://3dtoday.ru/questions/vopros-po-modelirovaniyu/