Selecting an occluded textured geometric element through alpha channels and selection override color via the API

You can select textured geometric elements through their alpha channels or through a selection override color and transparency via an external device such as a hand-held camera. This enables you to have the option to select through alpha channels and specify the camera to use.

Refer to the MotionBuilder SDK Help at: http://www.autodesk.com/motionbuilder-sdkdoc-2013-enu.