Hi Timothy,
What you have been accustomed to experiencing is the display of a "Simplified Model" during panning operations. You can pan with either the hand tool, or by pressing the center button of the mouse.
In Options > Work Environment > User Preference Schemes > Advanced Redraw Options, there are choices you can select for the model display during 2D navigation. The "Simplified Model" results in transparent fills, giving you the result that you want to see.
The default in AC 15 is "Full Model" - so that when you pan, you see everything with is normal appearance.
Just change that setting to "Simplified Model" and things should be back to the way you want. At least, testing with the 32 bit Windows version, it works. Hopefully 64 bit Windows is OK, too.
Mac users note: On my Lion machine, switching to Simplified Model still shows the full model during panning. It only shows the simplified model during zooming. Seems like a bug - maybe someone else can check?
Cheers,
Karl
PS The views other then Full Model were added so that people with slow graphics cards would not be impacted during 2D navigation. It is a side-effect that many of us (I'm with you) find it very handy to be able to "see through" our model during panning operations. I think that is why the behavior isn't really documented anywhere, even though it can be quite useful.
One of the forum moderators
AC 28 USA and earlier • macOS Sonoma 14.7.1, MacBook Pro M2 Max 12CPU/30GPU cores, 32GB