set Camera Mode to Terrain Centered and the Z Offset to 100 meters.
Compile and run.
The HMI window will display the OSG terrain in 3D.
Fine Tuning
The GdiOsg Sprite can use the setting of an OSG Viewer if one is defined. Otherwise, it will create one with default values.
The OSG Viewer must be disabled (and a Console viewer can be used, or any other).
The GdiOsg filename and Camera settings have been deprecated and removed from the window. The terrain filename must now be set in the Terrain::3D Settings and the camera must be set in the OSG Viewer itself.
vsTASKER simulation engine will create only one osg_root node for the whole simulation.
The OSG setting is done in the user modifiable /src/OSG/osg_setup.cpp
This file is compiled with the project when needed.