sphere from points another method is to first find the center of the circle defined by sets of points and intersecting the normals from there this would also define the circle center however small numerical imprecisions would make the lines not intersect supposedly planes have to intersect in a unique point if they are not parallel having thought about this why don t you project the lines onto the d plane formed by the lines do an intersection calculation in the plane in d where you re guaranteed a unique solution unless they re parallel which won t happen in this case and then use parametric distance along the lines from the circle centres to determine the exact point of interest this bypasses the messy error propogation required to do the calculation in d hope i haven t put my foot in it again steve steven collins email steve crl hitachi co jp visiting computer graphics researcher phone hitachi central research lab tokyo fax
