1. An image generator system for curvilinear displays wherein images are developed from polygons having edges defined by signal-represented vertices, said generator comprising: means for providing processed vertices signals defining edges for a desired image; generator means for converting said processed vertices signals specifying edges to test vertices signals, which signals are in spherical coordinates and specify said edges at least in terms of two differential angles; means for testing said test vertices signals specifying edges with respect to predetermined segmentation criteria to provide signals representative of acceptance or rejection; means for segmenting said processed vertices signals defining an edge into other processed vertices signals defining plural equivalent edges, said means for segmenting connected for operation on occurrence of a rejection signal from said means for testing; means for cycling said processed vertices signals defining edges through said generator means to said means for testing and through said means for segmenting to said means for providing processed vertices signals, to ultimately attain corrected vertices signals defining said edges in accordance with said predetermined segmentation criteria; and means coupled to receive said corrected vertices signals for displaying images.