Hi Tom,

My reason for asking related to a problem specific to rendered images with grain set stones like pave.
Matrix had a script which not only layout the stones & beads (aka grains or claws) relevant to the surface but also a "bearing cutter" that was used to boolean out the area to create a "seat" for the stones pavilion.

For "real world" use, this boolean cutter wasn't really required, only a positioning dimple/marker (traditionally a drilled hole) which a skilled Setter would open up with burrs to seat each individual stone & cut up the grains (claws) to hold them.

Those using Matrix for creating realistic renders of designs with pave diamonds found they DIDN'T quite look realistic.
This was caused by the boolean bearing cutter working fine for a "real world" STL model but not for its rendering.
Unlike "real world", the render model needed the bearing cutter to be larger than the stone so the rendered metal didn't interact with how the diamond material worked.
This situation was happening when using V-Ray but think it was also happening for those using Keyshot too.

So bottom line, you had to create two different models, one for render use only & one for STL "real world" use...and don't ever mix them up!!

I did a few models featuring "stone work" but never bothered trying to do a complete pave layout within MoI.
Good Luck

HTH, Colin

Hi Tom,
I did not use iso curves.
I projected a datum line onto the surface and used the vertical edge as the other datum.
Taking dimensions shown on photo I swept circles and used the pipe produced to cut surface.
The cut edge is used to sweep and cut the next edge and so on.
These cut edges are converted to curves by copying to clipboard and pasting back to become the grid.
You can boolean union the cut surface or take a copy before cutting.
I produced grid lines in the 'Y' as a check but this was not needed in this case as array along curve by
distance seemed ok.
Cheers
Barry

Edit: Forgot your 2 question.
No its not the ArrayGem option.
It's the array along curve which as a align to surface button and an option to space by distance.

This is the image. Anyone who may know more about the kind
of stone-setting / prongs / construction used in this objects -
any information is appreciated !

Hi Tom,
Colin's advice is excellent.
Barry's technique is elegant, and the way to do the layout, absent the exotic pave physics,
IMHO.

I was focused on creating a flat surface, for flow method. Your gem surface is not developable, but the horizontal and vertical lines indicate that (near) planar tiling methods or layouts can make good patterns. Tiling theory permits a finite number of uniform layouts of polygons. Hex tiling is among these. (= circle packing). Cell distortions for your surface should be limited, and can be compensated for by the artist. Patches on the frog have separation zones.

Using a spare surface, strips/ curves (edges), can be done by MoI array of a bunch of lines, and trim. MoI often has alternative ways to accomplish a task.
The iso-curves of your surface are "angulated", absent remeshing?

- Brian

ps came across a Java, open source, academic, biology, use of (charting force).

Hi Brian,
not sure if it's of any interest but Freecad as a surface/mesh unwrap tool.
It's in the mesh designer workbench (samples attached of surface taken from Tom's model).
Meshmixer as a unwrap option as well.
I don't think flow is an option in this case though.
Cheers
Barry
Edit:
Split surface prior to flattening file added.

Thank you Barry.
I'll have a look later.

Another possibility, if it works or not, HexaGrid On Surface, from food for Rhino (uses Grasshopper). Circa 2012, so may have issues???
I think all the methods have geometry limitations to compensate for...Cell distortion, fixed gem size...

- Brian

Hi Barry - very thankful for your explanations, that helped a lot !

What do you think about the option tu use "intersectCurve" to generate
the curves instead of cut. copy an paste ?

Did you array the whole group of gem+prongs or each of the elements
individually ?

Hi Tom,
Yes the intersect curve could be used but the tube does not always cut thro both sides.
I arrayed the gem & posts every other grid curve & just the gem in the middle.
The method using the tube cutters maintains the rigid dimensions the gem & post make.
So if there is a large curvature on the surface the centre dimensions are maintained.
See photo.
Hope this helps.
Barry

Hi Tom,

That piece shows how proper pave is done with hand cut grains.
The whole idea of "pave" is that it should look like a "paving of stones".
The metal "spaces" (islands) that are left between each stone then get "cut up" to form the grains (claws)
Each of those grains gets pushed over the seated stone & is "beaded" (rounded & burnished) down onto the stones "crown" (angled top edges)

This technique is not something that every Jeweller can do, most will shop this work out to a highly skilled Setter who specialises in it.
In a "real world" situation, the metal piece would typically be handed over to the Setter along with a bag of stones & HE would do the layout & markings to drill, then open up each hole to fit each individual stone.
Here's a few YouTube videos that'll give you a better insight of what happens & how it's done.
https://youtu.be/_h-VQavSPWM
https://youtu.be/cqaIAlSIagQ

The CAD versions of this technique being created within Rhino/ RhinoGold/Matrix/MatrixGold is just a poor man's copy.
You can emulate the basic look of pave in CAD but it never looks truly like the "real article".

HTH, Colin

Thanks Colin - those Setters do have incredible skills ! Unbelievable what they achieve at such
microscopic scale !
I agree, the CAD pave looks pretty "industrial" and lifeless compared to the handmade ones.
A realistic rendered fake look could maybe be achieved by using sculpting tools. Any images
with closeups of such handmade grains you may know of, just post them here please.

Hi Brian, I agree, fantastic advice !

I am pretty impressed by those automated pave tools, but I also like to cook up my own
soup - with the kind help of amazingly skilled MOIers ;-)


""MoI often has alternative ways to accomplish a task.""

MOI has its own very individual and ingenious philosophy which could not be better expressed
as in its name : "Moments Of Inspiration" It is exactly its reduction to a handy array of essential tools
which makes the magic work - its more an artists workshop than an industrial hall jam packed with
an infinite number of hightech tools. Thats why I love to work with it as it matches my own philosophy
in so many aspects.

""The iso-curves of your surface are "angulated", absent remeshing?""
Sorry, I dont get what you mean.

Barry, btw, is the Dimension tool you used in the screenshot one of MOIs scripts ?

Hi Tom,
The dimension tool is in the latest V4 beta.
Barry

Colin, those videos have been very instructive. So there are many options to achieve a
diamond covered "pave" surface : From a pure geometrical one with cylindrical prongs
like being used in specialized software solutions like Rhino to more sculptural, organic
approaches like shown in the picture of the panther ring I posted, up to the "classical pave"
shown in the last video where the diamonds are embedded in metal which is treated rather
organically like cement than as a geometrical shape.

I have unsuccessfully tried to find an extensive and illustrated treatise about all the aspects
of the pave technique, it looks like there is more information around as video.

Hi Tom,
I think this video maybe of interest.
https://www.youtube.com/watch?v=Y00EEeZC4x4&list=PLCoK1Ao0T01KhfestF7xCic1jf5YjXiVh&index=13

As a test I took your model into blender and was able to pick gems from the JewelCraft addon
and place them on the surface of your model.
Also you can add the prongs as and where you want.
Anyway I think it's worth a look.
Cheers
Barry

Hi Tom,

There are specific books that cover the technical aspects of pave setting but they're not cheap.
It should also be noted that within pave, there's what Setters loosely describe as "American style" or a "Euro style".
Basic techniques are the same but knowing there's a difference within styles could help when looking at various references.

I've attached a PDF which Stuller released to help novice Jewellers venturing into CAD.
Given you're venturing into jewellery design then I figured its info might prove to be helpful?
I'm also including a ZIP file with a collection of different stone shapes in NURBS that I've collected from various sources.
You'll find these to be much more useful than the DXF versions available on the web.

For constructing your model with round stones just use a simple rotated shape to keep the file small.
Then just substitute those for the NURBS version when it comes time to doing your render.

HTH, Colin

Precious documentation and amazing Blender videos!

Hi Barry, wow that is amazing, did not know that Blender has that much
features, will have a look now !

Colin, thank you so much for your Christmas gift ;-)

I REALLY appreciate your kind tips, links and files !! It is not so easy
to find information about this specialized topic, so it makes your infos
specially valuable. Downloaded your files and will have a look at them
right now at my working computer.

Hi Tom,

No prob's & glad to hear they'll be useful.
I don't profess to be any kind of expert with regards to pave, I've just accumulated info from those much more knowledgeable on the subject.

If looking for good examples of real jewellery then try searching for old stuff by Cartier & Tiffany as they were "hi-end" Makers.
Genuine old Art Nouveau stuff will have "animal subjects" & any with pave will be ALL done by hand, so that's your better reference.
Same will apply to Art Deco period as it was heavy with pave but being more geometric style, a lot of it's pieces are typically flat & so wont offer the same kind of reference.

Cartier's "Panther" range would be another good reference source.
https://www.cartier.com.au/en-au/maison/cartier-and-the-panther/the-panther-through-time.html

HTH, Colin