clavis-magna

float x = 100;
float y = 100;
float xSpeed = 1;
float ySpeed = 3.3;

void setup(){
  size(200,200);
  smooth();
  background(255);
}

clavis-magna

var X_AXIS = new THREE.Vector3(1,0,0); //arbitrary vector local to object
var focusVector = new THREE.Vector3();
var localRot = new THREE.Quaternion();

//convert local rotation from Euler to Quaternion and store it in localRot
localRot.setFromEuler(object.mesh.rotation);
//multiply to quat by the vector we want to cast the ray towards (locally to the casting object)  
//store resulting vector in focusVector
localRot.multiplyVector3(X_AXIS, focusVector);

clavis-magna

//following two rotation functions are updated versions of code from: https://github.com/mrdoob/three.js/issues/1219
//updated to work in latest versions (r52 tested) of THREE.js

// Rotate an object around an axis in object space
var rotationMatrix
function rotateAroundObjectAxis( object, axis, radians ) {
    rotationMatrix = new THREE.Matrix4();
    rotationMatrix.makeRotationAxis( axis.normalize(), radians );
    object.matrix.multiplySelf( rotationMatrix );                       // post-multiply
    object.rotation.setEulerFromRotationMatrix(object.matrix, object.order);