Adjust Aspect Ratio of 3D-View / IGT-Viewpoint

Hi,

For an augmented reality implementation i am using the Viewpoint-function of the IGT-Module.

I would like to adjust the aspect ratio of the 3D-View-Window, in which die viewpoint-perspective is displayed, so that the image (which is exported via webserver) has the same aspect ratio as the image of the real camera. How can this be done?

Thx in advance!