add THREE.Rotation and remove Object3D.useQuaternion (as we always use quaternion now.) Following recommendation discussed here: https://github.com/mrdoob/three.js/issues/3404#issuecomment-17262516

examples/js/controls/FlyControls.js

@@ -19,8 +19,6 @@ THREE.FlyControls = function ( object, domElement ) {
 
 	// disable default target object behavior
 
-	this.object.useQuaternion = true;
-
 	// internals
 
 	this.tmpQuaternion = new THREE.Quaternion();

examples/js/loaders/ColladaLoader.js

@@ -868,7 +868,6 @@ THREE.ColladaLoader = function () {
 		var props = node.matrix.decompose();
 		obj.position = props[ 0 ];
 		obj.quaternion = props[ 1 ];
-		obj.useQuaternion = true;
 		obj.scale = props[ 2 ];
 
 		if ( options.centerGeometry && obj.geometry ) {

src/cameras/Camera.js

@@ -27,15 +27,7 @@ THREE.Camera.prototype.lookAt = function () {
 
 		m1.lookAt( this.position, vector, this.up );
 
-		if ( this.useQuaternion === true )  {
-
-			this.quaternion.setFromRotationMatrix( m1 );
-
-		} else {
-
-			this.rotation.setFromRotationMatrix( m1, this.rotation.Order );
-
-		}
+		this.quaternion.setFromRotationMatrix( m1 );
 
 	};
 

src/core/Object3D.js

@@ -17,9 +17,12 @@ THREE.Object3D = function () {
 	this.up = new THREE.Vector3( 0, 1, 0 );
 
 	this.position = new THREE.Vector3();
-	this.rotation = new THREE.Euler();
+	this.quaternion = new THREE.Quaternion();
 	this.scale = new THREE.Vector3( 1, 1, 1 );
 
+	// for backwards compatibility (maps changes to this.rotation onto this.quaternion)
+	this.rotation = new THREE.Rotation( this.quaternion );
+
 	this.renderDepth = null;
 
 	this.rotationAutoUpdate = true;
@@ -30,9 +33,6 @@ THREE.Object3D = function () {
 	this.matrixAutoUpdate = true;
 	this.matrixWorldNeedsUpdate = true;
 
-	this.quaternion = new THREE.Quaternion();
-	this.useQuaternion = false;
-
 	this.visible = true;
 
 	this.castShadow = false;
@@ -68,15 +68,7 @@ THREE.Object3D.prototype = {
 
 			m1.extractRotation( this.matrix );
 
-			if ( this.useQuaternion === true )  {
-
-				this.quaternion.setFromRotationMatrix( m1 );
-
-			} else {
-
-				this.rotation.setFromRotationMatrix( m1, this.rotation.order );
-
-			}
+			this.quaternion.setFromRotationMatrix( m1 );
 
 		}
 
@@ -94,18 +86,7 @@ THREE.Object3D.prototype = {
 
 			q1.setFromAxisAngle( axis, angle );
 
-			if ( this.useQuaternion === true ) {
-
-				this.quaternion.multiply( q1 );
-
-			} else {
-
-				q2.setFromEuler( this.rotation );
-				q2.multiply( q1 );
-
-				this.rotation.setFromQuaternion( q2, this.rotation.order );
-
-			}
+			this.quaternion.multiply( q1 );
 
 			return this;
 
@@ -124,15 +105,7 @@ THREE.Object3D.prototype = {
 
 			v1.copy( axis );
 
-			if ( this.useQuaternion === true ) {
-
-				v1.applyQuaternion( this.quaternion );
-
-			} else {
-
-				v1.applyEuler( this.rotation );
-
-			}
+			v1.applyQuaternion( this.quaternion );
 
 			this.position.add( v1.multiplyScalar( distance ) );
 
@@ -213,15 +186,7 @@ THREE.Object3D.prototype = {
 
 			m1.lookAt( vector, this.position, this.up );
 
-			if ( this.useQuaternion === true )  {
-
-				this.quaternion.setFromRotationMatrix( m1 );
-
-			} else {
-
-				this.rotation.setFromRotationMatrix( m1, this.rotation.order );
-
-			}
+			this.quaternion.setFromRotationMatrix( m1 );
 
 		};
 
@@ -393,17 +358,7 @@ THREE.Object3D.prototype = {
 
 	updateMatrix: function () {
 
-		// if we are not using a quaternion directly, convert Euler rotation to this.quaternion.
-
-		if ( this.useQuaternion === false )  {
-
-			this.matrix.makeFromPositionEulerScale( this.position, this.rotation, this.scale );
-
-		} else {
-
-			this.matrix.makeFromPositionQuaternionScale( this.position, this.quaternion, this.scale );
-
-		}
+		this.matrix.makeFromPositionQuaternionScale( this.position, this.quaternion, this.scale );
 
 		this.matrixWorldNeedsUpdate = true;
 
@@ -450,7 +405,8 @@ THREE.Object3D.prototype = {
 		object.up.copy( this.up );
 
 		object.position.copy( this.position );
-		if ( object.rotation instanceof THREE.Euler ) object.rotation.copy( this.rotation ); // because of Sprite madness
+		object.quaternion.copy( this.quaternion );
+		object.rotation = new THREE.Rotation( object.quaternion );		
 		object.scale.copy( this.scale );
 
 		object.renderDepth = this.renderDepth;
@@ -463,9 +419,6 @@ THREE.Object3D.prototype = {
 		object.matrixAutoUpdate = this.matrixAutoUpdate;
 		object.matrixWorldNeedsUpdate = this.matrixWorldNeedsUpdate;
 
-		object.quaternion.copy( this.quaternion );
-		object.useQuaternion = this.useQuaternion;
-
 		object.visible = this.visible;
 
 		object.castShadow = this.castShadow;

src/extras/animation/Animation.js

@@ -41,12 +41,6 @@ THREE.Animation.prototype.play = function ( loop, startTimeMS ) {
 
 			object = this.hierarchy[ h ];
 
-			if ( this.interpolationType !== THREE.AnimationHandler.CATMULLROM_FORWARD ) {
-
-				object.useQuaternion = true;
-
-			}
-
 			object.matrixAutoUpdate = true;
 
 			if ( object.animationCache === undefined ) {

src/extras/animation/KeyFrameAnimation.js

@@ -75,7 +75,6 @@ THREE.KeyFrameAnimation.prototype.play = function( loop, startTimeMS ) {
 
 			object = this.hierarchy[ h ];
 			node = this.data.hierarchy[ h ];
-			object.useQuaternion = true;
 
 			if ( node.animationCache === undefined ) {
 

src/extras/helpers/ArrowHelper.js

@@ -23,8 +23,6 @@ THREE.ArrowHelper = function ( dir, origin, length, hex ) {
 
 	this.position = origin;
 
-	this.useQuaternion = true;
-
 	var lineGeometry = new THREE.Geometry();
 	lineGeometry.vertices.push( new THREE.Vector3( 0, 0, 0 ) );
 	lineGeometry.vertices.push( new THREE.Vector3( 0, 1, 0 ) );

src/loaders/SceneLoader.js

@@ -346,7 +346,6 @@ THREE.SceneLoader.prototype.parse = function ( json, callbackFinished, url ) {
 							if ( quat ) {
 
 								object.quaternion.fromArray( quat );
-								object.useQuaternion = true;
 
 							} else {
 
@@ -437,8 +436,7 @@ THREE.SceneLoader.prototype.parse = function ( json, callbackFinished, url ) {
 					if ( quat !== undefined ) {
 
 						camera.quaternion.fromArray( quat );
-						camera.useQuaternion = true;
-
+				
 					} else if ( rot !== undefined ) {
 
 						camera.rotation.fromArray( rot );
@@ -466,8 +464,7 @@ THREE.SceneLoader.prototype.parse = function ( json, callbackFinished, url ) {
 					if ( quat ) {
 
 						object.quaternion.fromArray( quat );
-						object.useQuaternion = true;
-
+				
 					} else {
 
 						object.rotation.fromArray( rot );
@@ -549,8 +546,7 @@ THREE.SceneLoader.prototype.parse = function ( json, callbackFinished, url ) {
 		if ( q ) {
 
 			node.quaternion.fromArray( q );
-			node.useQuaternion = true;
-
+	
 		} else {
 
 			node.rotation.fromArray( r );

src/math/Rotation.js

@@ -0,0 +1,83 @@
+/**
+ * @author mrdoob / http://mrdoob.com/
+ * @author bhouston / http://exocortex.com/
+  */
+
+THREE.Rotation = function ( quaternion ) {
+
+    this.euler = new THREE.Euler();
+    this.quaternion = quaternion;
+
+};
+
+THREE.Rotation.prototype = {
+
+    get x () {
+
+        return this.euler.x;
+
+    },
+
+    set x ( value ) {
+
+        this.euler.x = value;
+        this.quaternion.setFromEuler( this.euler );
+
+    },
+
+    get y () {
+
+        return this.euler.y;
+
+    },
+
+    set y ( value ) {
+
+        this.euler.y = value;
+        this.quaternion.setFromEuler( this.euler );
+
+    },
+
+    get z () {
+
+        return this.euler.z;
+
+    },
+
+    set z ( value ) {
+
+        this.euler.z = value;
+        this.quaternion.setFromEuler( this.euler );
+
+    },
+
+    set: function ( x, y, z ) {
+
+        this.euler.x = x;
+        this.euler.y = y;
+        this.euler.z = z;
+
+        this.quaternion.setFromEuler( this.euler );
+
+    },
+  
+    copy: function ( rotation ) {
+
+        this.quaternion.copy( rotation.quaternion );
+
+    },
+
+    fromArray: function() {
+
+        this.euler.fromArray( array );
+        this.quaternion.setFromEuler( this.euler );
+
+    },
+
+    toArray: function () {
+
+        return this.euler.toArray();
+
+    }
+
+};

src/objects/SkinnedMesh.js

@@ -35,8 +35,7 @@ THREE.SkinnedMesh = function ( geometry, material, useVertexTexture ) {
 			bone.name = gbone.name;
 			bone.position.set( p[0], p[1], p[2] );
 			bone.quaternion.set( q[0], q[1], q[2], q[3] );
-			bone.useQuaternion = true;
-
+		
 			if ( s !== undefined ) {
 
 				bone.scale.set( s[0], s[1], s[2] );

utils/build/includes/common.json

@@ -6,6 +6,7 @@
 	"src/math/Vector3.js",
 	"src/math/Vector4.js",
 	"src/math/Euler.js",
+	"src/math/Rotation.js",
 	"src/math/Line3.js",
 	"src/math/Box2.js",
 	"src/math/Box3.js",

utils/build/includes/common2.json

@@ -5,6 +5,8 @@
 	"src/math/Vector2.js",
 	"src/math/Vector3.js",
 	"src/math/Vector4.js",
+	"src/math/Euler.js",
+	"src/math/Rotation.js",
 	"src/math/Box2.js",
 	"src/math/Box3.js",
 	"src/math/Matrix3.js",

utils/build/includes/math.json

@@ -6,6 +6,7 @@
 	"src/math/Vector3.js",
 	"src/math/Vector4.js",
 	"src/math/Euler.js",
+	"src/math/Rotation.js",	
 	"src/math/Line3.js",
 	"src/math/Box2.js",
 	"src/math/Box3.js",