three.js rotate object on mouse down and move

Question

I'm trying to get a good mouse movement in my scene so I can rotate around the object.

I have two problems, I can figure out how to limit the movement so that it never rotates below 0 degrees on the Y axis. (I dont want to see the object from below, only above)

And the second thing I can't figure out is how to make the movement smooth. Now with what I have achieved in the jsfiddle is that the camera moves back to its starting position before starting to rotate.

My try: http://jsfiddle.net/phacer/FHD8W/4/

This is the part I dont get:

var spdy =  (HEIGHT_S / 2 - mouseY) / 100;
var spdx =  (WIDTH / 2 - mouseX) / 100;

root.rotation.x += -(spdy/10);
root.rotation.y += -(spdx/10);

What I want without using an extra library: http://www.mrdoob.com/projects/voxels/#A/afeYl

Answer 1

You can rotate you scene with this code,

To ensure to not rotate under 0, simule rotation of a vector (0,0,1) and check if y of vector is negative

var mouseDown = false,
        mouseX = 0,
        mouseY = 0;

    function onMouseMove(evt) {
        if (!mouseDown) {
            return;
        }

        evt.preventDefault();

        var deltaX = evt.clientX - mouseX,
            deltaY = evt.clientY - mouseY;
        mouseX = evt.clientX;
        mouseY = evt.clientY;
        rotateScene(deltaX, deltaY);
    }

    function onMouseDown(evt) {
        evt.preventDefault();

        mouseDown = true;
        mouseX = evt.clientX;
        mouseY = evt.clientY;
    }

    function onMouseUp(evt) {
        evt.preventDefault();

        mouseDown = false;
    }

    function addMouseHandler(canvas) {
    canvas.addEventListener('mousemove', function (e) {
        onMouseMove(e);
    }, false);
    canvas.addEventListener('mousedown', function (e) {
        onMouseDown(e);
    }, false);
    canvas.addEventListener('mouseup', function (e) {
        onMouseUp(e);
    }, false);
}

    function rotateScene(deltaX, deltaY) {
    root.rotation.y += deltaX / 100;
    root.rotation.x += deltaY / 100;
}