Q. How can I make an object not transformable in the viewer?

A. In Version 3.1 of AVS/Express, there is a new transform mode called "Locked". When an object is locked, it will not be transformed, even if the Top object is transformed. An object's transform mode can be set on the Data Viewer's Object Editor panel.

Note that you can also make an object not pickable (through the Data Viewer's Object Editor panel), which means the object cannot be selected and transformed by the user. However, the user can still transform the Top object and the non-pickable object would be transformed.