.. I Can see the raindrops on the windshield on 2D mode, but not when I switch to 3D mode, why ? ... it's is very unrealistic

.. I Can see the raindrops on the windshield on 2D mode, but not when I switch to 3D mode, why ? ... it's is very unrealistic

You can't see raindrops in the VC because Aces made a design decision during development and programmed them out. Putting them back requires a developer to go outside the SDK (Usually using code from FS8/9) which generally causes a significant frame rate hit as well as creating future compatibility problems. Raindrops on the VC windshield are a tiny gain for a giant expenditure of resources. Not cost-effective in the words of one of the Aces team. I doubt many developers are willing to make that trade so get used to disappointment.

Putting them back requires a developer to go outside the SDK (Usually using code from FS8/9) which generally causes a significant frame rate hit as well

Just that it doesn't. Ant (Ant's Airplanes) has disproved this several times.I highly doubt Carenado would do raindrops considering they still haven't done 3D gauges.