Add Quadrilateralized Spherical Cube (QSC) projection (patch attached).
|Reported by:||marlam||Owned by:||warmerdam|
The attached patch (which applies to SVN revision 2226, current as of 2012-07-13) adds support for the Quadrilateralized Spherical Cube (QSC) projection.
This projection is designed to be used with a cube model that subdivides the ellipsoid into six areas. The projection then maps each area to a square map (the corresponding cube side).
Such a cube model is very well suited for planetary-scale terrain rendering, as it allows quadtree-based data management.
A cube model can also use Gnomonic projection, but this introduces strong angle and area distortions. In contrast, QSC projection is an equal-area projection and at the same time introduces only limited angle distortions.