How to rotate object around a point?

Comments

• MarcCCTx Posts: 909

  October 2017 edited October 2017

  Just parent the item to a null object (tool bar or create menu) placed at that vector. Rotating the null rotates the child object.

  Post edited by MarcCCTx on October 2017
• jag11 Posts: 885

  October 2017

  This script might help you, to see it working you need to create two spheres, name them, "sun", and "earth", run the script.

   

  var Program = (function () {    function Program() {        this.programName = "Orbit";    }    Program.prototype.run = function () {        var sun = Scene.findNodeByLabel("sun");        var earth = Scene.findNodeByLabel("earth");        this.orbit(sun, earth, new DzVec3(0, 1, 0), 45 / 2);    };    Program.prototype.orbit = function (planet, moon, axis, angle) {        var DEG2RAD = Math.PI / 180;        var RAD2DEG = 180 / Math.PI;        beginUndo();        var origin = new DzVec3(0, 0, 0);        var planetPosition = planet.getWSPos();        var moonPosition = moon.getWSPos();        var pointToRotate = origin.subtract(planetPosition.subtract(moonPosition));        var q = new DzQuat(axis, angle * DEG2RAD);        this.applyQuaternion(pointToRotate, q);        moon.setWSPos(pointToRotate.add(planetPosition));        var currentRot = moon.getWSRot();        acceptUndo(this.programName);    };    Program.prototype.applyQuaternion = function (v, q) {        var x = v.x;        var y = v.y;        var z = v.z;        var qx = q.x;        var qy = q.y;        var qz = q.z;        var qw = q.w;        var ix = qw * x + qy * z - qz * y;        var iy = qw * y + qz * x - qx * z;        var iz = qw * z + qx * y - qy * x;        var iw = -qx * x - qy * y - qz * z;        v.x = ix * qw + iw * -qx + iy * -qz - iz * -qy;        v.y = iy * qw + iw * -qy + iz * -qx - ix * -qz;        v.z = iz * qw + iw * -qz + ix * -qy - iy * -qx;        return v;    };    return Program;}());var program = new Program().run();

   
• Syrus_Dante Posts: 983

  December 2017 edited December 2017

  It seems like you are constructing a privat ? not anonymous function called Orbit - can I have acces to it from outside like from the main anonymous function and how do I execute it if so?

  var Program = (function () {    function Program() {        this.programName = "Orbit";    }

  This seems to start an endless loop right?

  var program = new Program().run();

   

  Post edited by Syrus_Dante on December 2017
• jag11 Posts: 885

  December 2017

  As a matter of fact, all member methods are public. All that is needed to access them is an instance, like:

  var sun = Scene.findNodeByLabel("sun");var earth = Scene.findNodeByLabel("earth");var program = new Program();program.orbit(sun, earth, new DzVec3(0, 1, 0), 45 / 2);

  The run method just contains 3 statements, no loop. It was supposed to be a Fluent like method but forgot to return this.

  HTH
• Syrus_Dante Posts: 983

  December 2017

  Sorry it's my lack of knowledge of this syntax that has led me to believe that this is an endless loop. I'm shure its an insult to any programmer.
• jag11 Posts: 885

  December 2017

  Actually it is not a syntax, it's called a Design Pattern, a fancy name to help you write S.O.L.I.D. code.