Simple proof of concept built with Qt 3D to evaluate the possibility of using Qt 3D framework for 3D map view in QGIS in the future.
The demo application creates a terrain model from a DEM raster layer and applies aerial imagery as texture of the mesh.
The viewer allows basic interaction: keyboard arrows and page up/down to move camera, drag left mouse button to change camera orientation.
Tested with Qt 5.8 on Linux.