split plot in upper and lower hemisphere
1: axis given -> no sphericalRegion stored -> compute sphericalRegion -> finish 2: axis is hold and has sphericalRegion -> use multiplot 3: new multiplot
split plot in upper and lower hemisphere
1: axis given -> no sphericalRegion stored -> compute sphericalRegion -> finish 2: axis is hold and has sphericalRegion -> use multiplot 3: new multiplot