Procedurally Generated mesh using Vive controller drawing triangles backward. Help needed

In unity I'm creating a brush like prefab that creates a procedurally generated mesh, it takes vectors from the controllers position and creates a shape using them using indices to create the triangles that connect them.

The idea is when you move the controller you've created a 3d mesh. However the issue im getting is that when the controller is moved backwards (-z) the triangles are drawn inside out as I assume the indices are now considered to be drawing the triangle in a way that flips them. I've tried generating indices backwards when the controller moves backwards, but unfortunately the triangles aren't always drawn inside out when the controllers direction is x,y,-z.

from left to right: first is what it should look like, second is what it does look like now