THREE hexagon geometry - evenly subdivided

HexGeometry.js

/**
 * hexagon geometry - evenly subdivided
 * @param radius
 * @param {int=} segments - subdivisions
 * @param {Number=} theta - default "pointy top" (Math.PI/2 for "flat top")
 * @constructor
 * @author lmg / https://github.com/kishalmi
 */

THREE.HexGeometry = function (radius, segments, theta) {

	THREE.Geometry.call(this);

	this.radius = radius || 50;
	this.segments = (segments !== undefined) ? Math.max(1, segments) : 1;
	this.theta = (theta !== undefined) ? theta : 0;

	var n = new THREE.Vector3(0, 0, 1);

	// center
	this.vertices.push(new THREE.Vector3(0, 0, 0));
	var nVertex = 0;
	var nVertexRing = 1;

	// add rings
	for (var iRing = 1; iRing <= this.segments; iRing++) {
		var r = this.radius * iRing / this.segments;
		var nVertexInner = nVertex;
		nVertex = this.vertices.length;
		var nVertexRingInner = nVertexRing;
		nVertexRing = iRing * 6;

		for (var iSide = 0; iSide < 6; iSide++) {
			var a1 = this.theta + iSide / 6 * 2 * Math.PI;
			var a2 = this.theta + (iSide + 1) / 6 * 2 * Math.PI;
			var v1 = new THREE.Vector3(r * Math.sin(a1), r * Math.cos(a1), 0);
			var v2 = new THREE.Vector3(r * Math.sin(a2), r * Math.cos(a2), 0);

			for (var iLerp = 0; iLerp < iRing; iLerp++) {
				var l = iLerp / iRing;
				var iVertex = this.vertices.push(v1.clone().lerp(v2, l)) - 1;
				var iVertexRight = nVertex + (iVertex - nVertex + 1) % nVertexRing;
				var iVertexInnerRight = nVertexInner + (iVertex - nVertex - iSide) % nVertexRingInner;
				this.faces.push(new THREE.Face3(
					iVertexRight, iVertex, iVertexInnerRight,
					[n.clone(), n.clone(), n.clone()]
				));
				if (iLerp) {
					var iVertexInnerLeft = iVertex - nVertexRingInner - iSide - 1;
					this.faces.push(new THREE.Face3(
						iVertex, iVertexInnerLeft, iVertexInnerRight,
						[n.clone(), n.clone(), n.clone()]
					));
				}
			}
		}
	}

	// set UVs
	var geo = this;
	var v2uv = function (vIndex) {
		return new THREE.Vector2(
			0.5 + r / 2 * geo.vertices[vIndex].x,
			0.5 + r / 2 * geo.vertices[vIndex].y
		);
	};
	for ( var f = 0, fl = this.faces.length; f < fl; f ++ ) {
		var face = this.faces[f];
		geo.faceVertexUvs[0].push([v2uv(face.a), v2uv(face.b), v2uv(face.c)]);
	}

	this.computeCentroids();
	this.computeFaceNormals();

	this.boundingSphere = new THREE.Sphere(new THREE.Vector3(), radius);

};
THREE.HexGeometry.prototype = Object.create(THREE.Geometry.prototype);