Brilliant Cut

I had a desire to make an accurate brilliant cut diamond
shape ever since Frank B. made his bowl of jewels.

It turned out to be much harder than I thought.

The first problem is, as Martin pointed out recently, 4 sided
polygons have a tendency to get twisted, or non flat.

The brilliant cut has two sets of facets that are four
sided, one on the pavilion, and one on the crown.

These facets/polygons become twisted while building
the model and must be made flat during construction.

Even Hiroto's script does not do this properly, but It's a great
way to start. I wish I had used it during my testing as I built
this model over and over again with varying techniques.

The second problem is the girdle, which is not faceted, but
ground first while preparing the rough diamond for faceting.
The brilliant cut diamond is round. All other edges are hard.

To cut the girdle I Boolean subtracted a tube with 128 sections.

This may not make any difference visually because once you put the
diamond material on it you can't tell what's going on with the facets anyway.

First gif: Correct bright cut
Second gif: Script generated

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Thanks Kurt, I haven't had the chance to test that yet.

I've included the model, and blueprint image
I used, in case anyone wants to play with it.

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But a great challenge, this is a difficult model to build with precision.
I recommend trying it if you like a puzzle, but be warned it's not easy.

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Thanks Swiz.
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