Using Quaternion in libGDX

Question

Can someone give me an explanation about how to use the Quaternion class in libGDX to move my camera around a sphere or just set it up, manipulate it, and apply it general? I am trying to acheive orbiting my camera around a sphere without gimbal lock, and I'm not having any luck getting the camera to do anything by using quaternions...

Answer 1

I ended up getting this to work. To apply a Quaternion to your camera just do this:

public void update(boolean updateFrustum)
{
    float aspect = camera.viewportWidth / camera.viewportHeight;
    camera.projection.setToProjection(Math.abs(camera.near), Math.abs(camera.far), camera.fieldOfView, aspect);
    camera.view.setToLookAt(camera.position, tmp.set(camera.position).add(camera.direction), camera.up);

    // This is all you need to do!
    // the rotate() method takes in a Quaternion
    // It needs to be after the call to setToLookAt()
    camera.view.rotate(rotation);

    camera.combined.set(camera.projection);
    Matrix4.mul(camera.combined.val, camera.view.val);

    if (updateFrustum)
    {
        camera.invProjectionView.set(camera.combined);
        Matrix4.inv(camera.invProjectionView.val);
        camera.frustum.update(camera.invProjectionView);
    }
}

This is exactly the same as the update() method in the PerspectiveCamera class except for the part about adding the rotation quaternion.