Merge pull request #6125 from Lowfab/feature/edgesHelperCustomAngle

extend EdgesHelper to allow for a custom threshold angle

docs/api/extras/helpers/EdgesHelper.html

@@ -27,10 +27,12 @@
 		</code>
 
 		<h2>Constructor</h2>
-		<h3>[name]( [page:Object3D object], [page:Color color] )</h3>
+		<h3>[name]( [page:Object3D object], [page:Color color], [page:Float thresholdAngle] )</h3>
 		<div>
 		object -- Object of which to draw edges <br />
-		color -- Color of the edges.
+		color -- Color of the edges.<br />
+		thresholdAngle -- the minimim angle (in degrees), between the face normals of adjacent faces, that is required to render an edge. Default is 0.1.
+
 		</div>
 		<div>
 		Creates a [page:Line], showing only the "hard" edges of the passed object; specifically, no edge will be drawn between faces which are adjacent and coplanar (or nearly coplanar).

src/extras/helpers/EdgesHelper.js

@@ -1,10 +1,19 @@
 /**
  * @author WestLangley / http://github.com/WestLangley
+ * @param object THREE.Mesh whose geometry will be used
+ * @param hex line color
+ * @param thresholdAngle the minimim angle (in degrees),
+ * between the face normals of adjacent faces,
+ * that is required to render an edge. A value of 10 means
+ * an edge is only rendered if the angle is at least 10 degrees.
  */
 
-THREE.EdgesHelper = function ( object, hex ) {
+THREE.EdgesHelper = function ( object, hex, thresholdAngle ) {
 
 	var color = ( hex !== undefined ) ? hex : 0xffffff;
+	thresholdAngle = ( thresholdAngle !== undefined ) ? thresholdAngle : 0.1;
+
+	var thresholdDot = Math.cos( THREE.Math.degToRad( thresholdAngle ) );
 
 	var edge = [ 0, 0 ], hash = {};
 	var sortFunction = function ( a, b ) { return a - b };
@@ -67,7 +76,7 @@ THREE.EdgesHelper = function ( object, hex ) {
 
 		var h = hash[ key ];
 
-		if ( h.face2 === undefined || faces[ h.face1 ].normal.dot( faces[ h.face2 ].normal ) < 0.9999 ) { // hardwired const OK
+		if ( h.face2 === undefined || faces[ h.face1 ].normal.dot( faces[ h.face2 ].normal ) <= thresholdDot ) {
 
 			var vertex = vertices[ h.vert1 ];
 			coords[ index ++ ] = vertex.x;