MoI discussion forum
MoI discussion forum

Full Version: Sugarloaf Cabochon ?!

Show messages:  1-14  15-33

From: Barry-H
19 Apr 2022   [#15] In reply to [#14]
Hi Tom,
perhaps this method will give you the rounded peak needed.
I started with a square and added mid points to each side.
Then selected the mid points and scaled to give the desired curvature,
Offset copies made and added point for peak then lofted as per Burr's video.
Added a fillet running diagonal from corner to corner.
The other diagonal same radii but requires a second fillet set for the peak area to be slightly smaller.
hope that makes sense.
Cheers
Barry



Image Attachments:
Fillet Peak.png 


From: BurrMan
19 Apr 2022   [#16] In reply to [#12]
Here is another option...

Since it seems the surgarloaf is more of an "artistic grind" and not really a mathematically produced result, you can change the base shape and all the angles of the surface structure, along with Blend parameters to "Eyeball" some various results... All smooth.


From: bemfarmer
19 Apr 2022   [#17]
Sugarloaf cut video. Not in English (India).
https://www.youtube.com/watch?v=dsfqdqgxEyE

- Brian

Google search of "Cabo Gem Cut" shows several videos, (but not for sugarloaf), and the grinding equipment.
From: TOM (SIRTOM)
19 Apr 2022   [#18] In reply to [#16]
Amazing approach, Burrman. The video shows you using the Superellipse script.
Is there any difference to the Squircle script ?
From: bemfarmer
20 Apr 2022   [#19] In reply to [#18]
It is Burr's video that you refer to?

- Brian
From: TOM (SIRTOM)
20 Apr 2022   [#20]
Uh I guess I mixed up your names ... Yes, the Video shows Burrman using
the Superellipse script and as I did not find this one (I am using the "Squircle")
I wondered about the differnces.
From: bemfarmer
20 Apr 2022   [#21] In reply to [#20]
The superellipse2d script is from 2013, and includes a squircle, I think as a subset.

https://moi3d.com/forum/index.php?webtag=MOI&msg=5616.1

About February 2022, a different squircle, using a different math formula, was created, the Fernandez-Guasti squircle. (Later in above link.)
This version is not a subset of superellipse2d. (?)

- Brian

I looked up the pronunciation of squircle. Combine the rodent squirrel with ircle.
(still hasn't made it into spellchecker :-)
From: Phiro
20 Apr 2022   [#22]
On the first picture of this thread and in the video we see, the Sugarloaf Cabochon have 4 faces with edges.
With the video, I discover the render of this cut, that I see very rarely in stores.
Very nice cut...
From: TOM (SIRTOM)
20 Apr 2022   [#23] In reply to [#21]
Thank you Disovered lots if scripts at the link you posted and will give them a try.
From: BurrMan
20 Apr 2022   [#24] In reply to [#23]
Hi Tom,
Brian is the creator of these scripts. He has made several of the "mathematical formula" scripts that create well known geometrical shapes.

He is best to answer about them and if there is any difference (or similarity)
From: TOM (SIRTOM)
20 Apr 2022   [#25] In reply to [#24]
Since this impossible word "Squircle" nauseated my mind it mixes up the names Burrmen Benfarmer and Brian -sorry ;-)
From: BurrMan
20 Apr 2022   [#26] In reply to [#25]
Hey Tom... makes it harder to have to translate everything. Hang tough!

"Squircle"

Square + circle

Squ ircle


From: Mik (MIKULAS)
20 Apr 2022   [#27] In reply to [#20]
... another elegant way

Mik


Attachments:
Isect 2D curves.3dm

Image Attachments:
Icect 2D curves.jpg 


From: bemfarmer
20 Apr 2022   [#28]
This link shows a side view of a cabochon:
https://www.rockngem.com/filling-an-empty-space-and-enhancing-a-cabochon/
I had thought that it is a sugarloaf, but now think it is a "slab" for a pendant. ?

Learned a new word: "vug"
https://en.wikipedia.org/wiki/Vug

image host

- Brian
From: Grendel
20 Apr 2022   [#29]
Very nice Mik
From: TOM (SIRTOM)
23 Apr 2022   [#30]
Due to your kind collaboration this thread turned into a nice
compilation of how to achieve one goal by different means -
thank you all !!

As one contributor wrote, the shape of a "squircle" is aesthetically
very appealing. I wanted to apply this theme of "squaring the circle"
to the whole shape, starting with a circle at the bottom morphing
into a slightly rounded square at the top. The how to is attached
below.


Image Attachments:
Sugarloaf cabochon.jpg 


From: Frenchy Pilou (PILOU)
24 Apr 2022   [#31] In reply to [#30]
Cool result! :)
From: bemfarmer
24 Apr 2022   [#32] In reply to [#30]
Reproduced a close copy of Toms cab, using his images to reproduce curves.
Note that the two "acorn" shaped curves must be trimmed apart at the North and South poles, into 4 curves, for network to work. (Or kept separate during their creation.)
One-half "acorn" curve was created with two blends. A horizontal line segment was placed at the North pole, and a vertical line segment was placed at the squircle intersect point, and a blend done between. A second blend was done from said curve, down to a horizontal line segment at the south pole. Join for one curve.
Mirror and rotate for other 3 acorn half curves.
Rounded square, squircle, and lower circle curves were also created. The lower circle had to be a bit larger than the sketch IMHO.
Select all 7 curves, and do network.

Still attempting to load my old purchased copy of Keyshot 6.

- Brian
From: TOM (SIRTOM)
25 Apr 2022   [#33]
Hi Brian,

I attached my approach to the profile curve - MOI works so great
for stuff like that.




Image Attachments:
Sugarloaf cabochon2.jpg 


Show messages:  1-14  15-33