A flexibility of the built-in parametric shapes applies now
to shapes imported from GemCad ASCII file. With the DiamCalc 2.1
you can now change the crown height, pavilion depth and girdle
height along with the size.
New lighting models: "GemCad ISO", "GemCad ISO" + observer head
blockage, "GemCad COS", "GemCad COS" + observer head blockage.