Here are some geometry models based on the ancient concept of fitting a dome on to four aches. Included in the above models are unfolded sections to predict what patterns are needed to cut flat materials which may be used in the building process. However this will result in many slits between the flattened out faces. In real life models, stretching and wrinkling the material may result if seams are not made for each of these slits made by the software. The CAD models above do have many slits in the unfolded sections which are too small to see in the small pictures.
Some ferrocement builders use forms which are made with flat materials.
One popular method uses inflated molds which are like inflated balloons. The actual grid work pattern is optional. Triangulalating the structural gridwork is often preferred, to better resist deformation. This link will take you to a geodesic star pattern grid work which beautifully adapts to a dome form . Above is a quick CAD construction of a split donut cage design.