Topology3D Update: fix a bug of TopologyViewer3D (particles may disappear when dragging to the right top corner after multiple changes of viewer position: say left and pg up) by choosing a different ray plane which is perpendicular to z axis
Topology3D Update: fix a bug of TopologyViewer3D (particles may disappear when dragging to the right top corner after multiple changes of viewer position: say left and pg up) by choosing a different ray plane which is perpendicular to z axis

sparkslabs/kamaelia,sparkslabs/kamaelia,sparkslabs/kamaelia,sparkslabs/kamaelia,sparkslabs/kamaelia,sparkslabs/kamaelia,sparkslabs/kamaelia,sparkslabs/kamaelia,sparkslabs/kamaelia,sparkslabs/kamaelia