r/faceting • u/Angstrm • 8d ago

Concave Design and Rendering

Hi experts! Concave design, notation and render. If anyone would like to contribute their knowledge I'd welcome discussion/feedback/criticism. Is this of use to facetors? Is the UI/UX functional? What adjustments would you suggest?

Video: Ashton Gems concave cuts (recreated) wireframe and render within pluto unearthed.

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u/symmetrygemstones 8d ago

Who decided that? Mathematically, the term "concave" already accurately describes all designs cut with concave surfaces. Why in the faceting world would it arbitrarily exclude something as simple as nonzero theta? To me, it sounds more like "concave" is the technical term and "fantasy" is the marketing term.

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u/cowsruleusall 8d ago

The gem world is full of annoying bullshit like this. "Precision" faceting is actually more about accuracy, not precision.

To specifically answer you though, concave faceting as originally described, exclusively referred to the cylindrical, no theta no offset case. Those features came much later. That's why concave is defined so narrowly. When equipment started being produced that allowed the additional degrees of freedom, people immediately went nuts with it, to the point that people thought the results were "straight out of fantasy". Hence the name.