Cement Board and Imitation Log Siding

I'd been thinking about doing either a flat siding for houses, or convex curved imitation log siding with cement board with either chopped fiberglass or hemp cast into a mold. And so I did a layout to know where the geometry will put the dimensions for 5/8"thick, by 9-1/4" wide boards.

The imitation log is derived from what would seem like a 10-3/8 diameter log in slabs about three inches in depth.