2016-05-25 spherical to cartesian coords via @turan_kuranes_rs MATH spherical to cartesian coords http://psgraphics.blogspot.jp/2016/05/spherical-to-cartesian-coords.html equirectangular image to spherical coords http://psgraphics.blogspot.jp/2016/05/equirectangular-image-to-sperical-coords.html