This question already has an answer here:
What creates a calisson-like shaped light bokeh such as this one (made with Arri signature T/1.9) ? The further from the center the more present are the angles, why ?
Another lens (Zeiss Supreme T/1.8) gives another shape:
How (where in the lense) to craft this shape ? Yet, why (how) in the Zeiss case, the bokeh looks harder, even though the aperture is the same (1.8 ~ 1.9) ?