Arbortext IsoView > Programmer's Reference > Properties > ViewSize
  
ViewSize
This property sets the scale (zoom factor) of the representation as double (1..6400%). If you use this, we recommend to disable the ResizeToFit feature to avoid recursive effects. (See ResizeToFit.)
Introduced with Arbortext IsoView 1.0.
document.ivx1.ResizeToFit = false;
document.ivx1.ViewSize = 50;