Update loadObj.js

Author: sabiqusi

lib/loadObj.js

@@ -330,13 +330,22 @@ function loadObj(objPath, options) {
 
     // Given the cartesian 2 vertices of a polygon, determine if convex
     function isConvex(positions2D) {
+        var length = position2D.length;
         var turnDirection = getTurnDirection(positions2D[0], positions2D[1], positions2D[2]);
-        for (var i=1; i < positions2D.length-2; ++i) {
+        for (var i=1; i < length-2; ++i) {
             var currentTurnDirection = getTurnDirection(positions2D[i], positions2D[i+1], positions2D[i+2]);
             if (turnDirection * currentTurnDirection < 0) {
                 return false;
             }
         }
+        var currentTurnDirection = getTurnDirection(position2D[length-2], position2D[length-1], position2D[0]);
+        if (turnDirection * currentTurnDirection < 0) {
+	        return false;
+        }
+        currentTurnDirection = getTurnDirection(position2D[length-1], position2D[0], position2D[1]);
+        if (turnDirection * currentTurnDirection < 0) {
+	        return false;
+        }
         return true;
     }