Merge pull request #4769 from lpsinger/orbitcontrols_locking_near_poles

OrbitControls locking near poles

examples/js/controls/OrbitControls.js

@@ -98,6 +98,7 @@ THREE.OrbitControls = function ( object, domElement ) {
 	var pan = new THREE.Vector3();
 
 	var lastPosition = new THREE.Vector3();
+	var lastQuaternion = new THREE.Quaternion();
 
 	var STATE = { NONE : -1, ROTATE : 0, DOLLY : 1, PAN : 2, TOUCH_ROTATE : 3, TOUCH_DOLLY : 4, TOUCH_PAN : 5 };
 
@@ -284,11 +285,17 @@ THREE.OrbitControls = function ( object, domElement ) {
 		scale = 1;
 		pan.set( 0, 0, 0 );
 
-		if ( lastPosition.distanceToSquared( this.object.position ) > EPS ) {
+		// update condition is:
+		// min(camera displacement, camera rotation in radians)^2 > EPS
+		// using small-angle approximation cos(x/2) = 1 - x^2 / 8
+
+		if ( lastPosition.distanceToSquared( this.object.position ) > EPS
+		    || 8 * (1 - lastQuaternion.dot(this.object.quaternion)) > EPS ) {
 
 			this.dispatchEvent( changeEvent );
 
 			lastPosition.copy( this.object.position );
+			lastQuaternion.copy (this.object.quaternion );
 
 		}
 

src/math/Quaternion.js

@@ -313,6 +313,12 @@ THREE.Quaternion.prototype = {
 
 	},
 
+	dot: function ( v ) {
+
+		return this._x * v._x + this._y * v._y + this._z * v._z + this._w * v._w;
+
+	},
+
 	lengthSq: function () {
 
 		return this._x * this._x + this._y * this._y + this._z * this._z + this._w * this._w;