diff --git a/src/grid.py b/src/grid.py
--- a/src/grid.py
+++ b/src/grid.py
@@ -31,7 +31,7 @@ class Grid:
     p2=numpy.cross(c,d)
     vanish1=numpy.cross(p1,p2)
     # !! 32 bit int can overflow. keeping it reasonably small. might want to use a cleaner solution
-    vanish1=EPoint.fromProjective(vanish1).toProjective()
+    vanish1=EPoint.fromProjective(vanish1).toProjective() # !! EPoint fails with point in infinity
     
     p3=numpy.cross(a,d)
     p4=numpy.cross(b,c)