I am using C# and OpenTK for example code for a book I am writing on virtual globe and terrain rendering. I wanted to share some early screen shots. Everything is done using OpenGL 3.3 core profile (could be also be 3.2, we are not using any 3.3 features yet), which OpenTK has made so easy!
Day and night imagery blended based on light (sun) position. Vector data is only rendered over the day imagery using a deferred approach. The day imagery and vector data are from Natural Earth, the night imagery is from NASA Visible Earth.
Vector data from shapefiles. The thick (pixel size greater than one), outlined, anti-aliased polylines are rendered using a geometry shader. The star billboards are also rendering using a geometry shader, which expands points into quads. The star icon is from Yusuke Kamiyamane.
Slope-based terrain shading in a fragment shader. Steep areas are shaded using a stone texture and flat areas use a grass texture. Obviously, I am not an artist :).
Constant pixel width contour lines procedurally generated in a fragment shader based on terrain height.