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Rhino Help

I was wondering if CAD guys out there could help me. I need to figre
out how to deisgn a signet in Rhino 2.0. The kicker is i need
absolute control over the shape of the top. Is this possible? Would
someone care to reply off list if you caould help. I can design the
outline of what I want, but I can’t create a surface from those
lines. On another note, does anyone have any experience with the
plug-in Techgems??


I can help. Signet rings are quite difficult to model in Rhino. I
have a couple of different tutorials I can send to you. Write to me
at @Jeffrey_Everett3 Please note the spelling is different than
my name is spelled.


I’d be glad to try to help if I can, Zach. What do you mean by
"absolute control", though? It’s possible to do very fine modeling by
tweaking control points around, but it’s tedious and can be
frustrating. If this is something you can model more easily in clay
or wax, then using a 3d scanner , like a Roland Pix-4 to digitize the
sculpted surface might be the most expeditious way to go. You can
Drape that in Rhino, then then add or subtract the resulting surface
from the basic ring model.

Andrew Werby
[Is Techgems a Rhino plugin?]

Rhino is not the best tool for the job if you are making a complex
sculpted surface. You might look into one of the following programs
to give you that type of capability.

Vue de Esprit

All three are good at creating sculpted surfaces. ArtCAM is the only
of the three that is specifically for jewelry, and is certainly the
most powerful. The other two are terrain generators. You would have
to think in tems of your design being mounains on a big signet
plain. There is also a modeler out there that works by putting blobs
together that join like beads of mercury. I don’t remember the name,
but I think the technique is called metaballs. If you can’t invest in
new software for this project, you might also farm out that portion
of the ring to someone that has more appropriate software. Carl

I was wondering if CAD guys out there could help me. I need to
figure out how to design a signet in Rhino 2.0. The kicker is I
need absolute control over the shape of the top. 

Hi Zach, Last summer, I spent hours and hours studying the
construction technique of a signet ring posted by Giuseppe Massoni,
on the Rhino N.G. I probably learned more from that model about
ring construction with network surfaces, than anything I’ve seen or
read before or since then…Giuseppe’s ring, Rombo, was the
inspiration for a signet ring I made. His uses a rhomboid top, mine,
an octagon top. Jeffery Everett posted a signet ring challenge last
summer on the Rhino NG, that got a tremendous response. Do a search
and take a look at those models, too. I’ve also worked out some
other methods that aren’t as complicated which will also work,
depending on the ring shape. If you’d like to send me the file, I’d
be glad to take a look at it.

Jesse Kaufman
CAD/CAM Technology
Handcrafted Originality

While I certainly wouldn’t label a signet style as a complex
sculpted surface, NURBS based tools (such as Rhino) are still the
best tool for certain types of designs (such as signet rings).

Terrain editors are very handy for adding certain types of detail to
single surfaces. They work by the heightfield process, a process that
uses a gradient from black to white to describe a 3D surface, black
being the lowest point, white being the highest, and shades of gray
everything in-between. Bryce, Vue de Esprit, ArtCam, and a plethora
of other available programs are based on this process, and are
extremely limited in the creation of sculptural forms, being only
able to “extrude” a flat surface into a 3 dimensional terrain. ArtCam
does have the ability wrap the flat surface onto other surfaces
though. A far better heightfield displacement tool is zBrush as it
can displace textures normal to (meaning perpendicular to) a surface,
be it doubly curved or flat.

Users of Polygon and Sub-Division Surface type programs are likely
to be the most proficient in the creation of highly detailed, complex
sculpted surfaces. Some of the programs in this more expensive genre
are Maya, SoftImage, 3dsMax, and LightWave. They are more commonly
used for film production and gaming, but through the stl format (a
triangulated surface description), files created in these programs
can be produced in the real world by both additive and subtractive

There is a degree of interoperability between all these software
through the use of common file exchange formats. One can have the
best of all three genre; NURBS (Rhino), heightfield (ArtCam), and
poly/SubD (Maya), in order to produce virtual objects for production
in the physical world. There are however, severe limitations which
can be worked around within limits. As the years roll by, more and
more of the interoperability limitations are vanishing. Rhino, for
instance, in its next release, will feature polygon and possibly
Sub-Division Surface capability, and it already has heightfield

ArtCam should not be confused with a modeling program. Although it
does have some limited capability of surfacing, it is more of a
detailing program in it’s current scope. To work on any but the
simplest ring in ArtCam, the ring would have to be created in a
program outside of ArtCam (such as Rhino) and imported into it so
details (such as lettering or heightfield extrusions, etc) can be
added. It is actually quite brilliant in it’s implementation of bas
relief type extrusions. Cimagraphi is another contender in this
arena, and is also extremely capable for the same type of work as
ArtCam. I do expect to see continuing improvement in the jewelry mfg
field from ArtCam as DelCam, the authors, have expressed a sincere
desire to make it the best tool for jewelers in this class.

As a jewelry maker in the quest to model anything I can imagine, I
attempt to transcend the limitations of individual software by using
at least one software of each type and transferring files between
them when necessary. I must admit though, that in the real world,
Rhino is the program I use more for than 90% of my work. It is an
extremely capable 3D modeling tool.

Jeffrey Everett

I just wanted to say thanks for sending the tutorial. I checked it
out today at work and it is exactly what I needed. Thanks again Zach