# ConvexHullMesh fails for collinear points

I've got a List of PointLists, of which some contain only collinear points.

I now want to obtain all ConvexHullMeshes of my PointLists.

For more than two collinear points, the algorithm seems to fail:

ConvexHullMesh[{{1, 0}, {0, 0}, {-1, 0}}]


while

ConvexHullMesh[{{1, 0}, {-1, 0}}]


would work.

How can I have ConvexHullMesh give me the correct ConvexHull for those cases (i.e. a line: {{1,0},{-1,0}})?

• So then, couldn't you use the failure of the convex hull algorithms as a test of collinearity? – Jason B. Jul 15 '16 at 16:26