Centering Mesh

I am just learning about creating a Mesh in Code.
I have 4 vertices and 2 triangles. I applied a brush and all seemed well, until I tried to rotate the mesh on the y axis. It seems that the centerpoint is at one of the corners. How can move the Center of a mesh?

Regards,
Eric

The pivot of the mesh is at 0,0,0 when you create the mesh. If you create the mesh with one corner at 0,0,0 then the pivot will be at that corner. So position the vertices appropriately when you create the mesh.

If you need to change the pivot of an already create mesh use the mesh commands: PositionMesh, etc.