openjscad-aurora-webapp

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// title: Umbilical Torus generator
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// author: Bruce Mueller 
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// date: 2013/03/30 
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// license: Creative Commons CC BY-SA
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// description: adapted for OpenJSCAD.org by Rene K. Mueller 2013/03/30
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// inc = incremental segments
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// r = radius of circle
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// t = 'radius' of triangle -distance from center to vertex
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// a = angle of rotation of triangle
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// b = angle rotation around center of circle
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function tri(r,t,a,b) { return [(r + t*sin(a))*cos(b), (r+ t*sin(a))*sin(b), t*cos(a)]; }
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// module to generate a rotated triangle slice, inc degrees wide
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// (could not implement this in the for loop below)
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function wedge(r,t,i,inc) {
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	var a1 = tri(r,t,i/3,i);
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	var b1 = tri(r,t,120+i/3,i);
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	var c1 = tri(r,t,240+i/3,i);
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	j = i+inc;
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	var a2 = tri(r,t,j/3,j);
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	var b2 = tri(r,t,120+j/3,j);
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	var c2 = tri(r,t,240+j/3,j);
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	return polyhedron({
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		points: [a1,b1,c1,a2,b2,c2],
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		triangles: [ [0,1,2], [5,4,3], 
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			[3,4,0], [1,0,4],
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			[3,0,2], [3,2,5],
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			[5,2,4], [4,2,1] ] });
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}
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// created a conjoined set of triangular wedges around the circle
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function main() {
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   var inc = 10;
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   var o = [];
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   for(var i=0; i<360; i+=inc) {
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      o.push(wedge(2,1,i,inc));
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   }
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   return union(o).scale(10);        // would be more effectice & suitable to create just one polyhedron
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}
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