GPU ray casting of virtual globes

Accurately rendering an ellipsoid is a fundamental problem for virtual globes in GIS and aerospace applications where the Earth's standard reference surface is non-spherical. The traditional approach of tessellating an ellipsoid into triangles and rendering via rasterization has several drawbacks [Miller and Gaskins 2009]. Geodetic grid tessellations oversample at the poles (2a), which leads to shading artifacts and ineffective culling. Tessellations based on subdividing an inscribed platonic solid lead to problematic triangles crossing the International Date Line and poles (2b).