How to simulate clicking on "Top" of camera cube?

tianxiangxiong

I'd like to implement in DazScript what happens when you click on "Top" of a camera cube. The camera points down, but maintains other angles. I tried fiddling w/ Euler angle & quaternions but couldn't get it right.

var xAxis = 0;
var yAxis = 1;
var zAxis = 2;

var viewport = MainWindow.getViewportMgr().getActiveViewport();

var camera = viewport.get3DViewport().getCamera();

var angles = camera.getWSRot().getValue(xAxis, yAxis, zAxis);

var newQuat = new DzQuat(new DzRotationOrder(xAxis, yAxis, zAxis), new DzVec3(-Math.PI/2, angles.y, 0));

camera.setWSRot(newQuat);

 

This seems to work when the camera's y-rotation is b/t PI/2 & -PI/2, but not otherwise. I'm sure I'm missing some fundamental concept r.e. quaternions / Euler angles, but I figured I'd ask for help rather than run off & take a semester-long course.