Hi All,

I've made a tutorial that shows how to scale and array gemstones
on a channel band. Let me know if there are
any questions or if anything is unclear. The video is over 8 MB
so I posted it on a file-sharing site. There is also a more basic
version of it, that you can download.

Regards,

Jesse


DivShare File - Channelband2_jdk.zip

http://www.divshare.com/download/693774-13f

A true gem of tut Moi + Wink :)
Bravo !

Thanks Pilou! :-)

-Jesse

Very cool Jesse!

It looks like you're getting more and more "in the groove" of using the full breadth of stuff that is available in MoI. Like I saw some nice strategic use of construction lines there. Curve booleans where it is convenient in addition to solids booleans, ... This is great stuff.

- Michael

Now i just need the diamonds to make the perfect gift for my wife :-)

Hi Michael,

Thanks, I think I'm starting to get the hang of MoI :-)..
I mean, I'm learning to make the best use of the drawing tools,
especially the construction lines. What I used to do in two or three
separate steps, I can knock out with two or three construction lines,
right within a single operation.

I actually tried to use curve Booleans instead of solid to punch
out the holes for the stones, but they cut through both sides
of the ring... so unless there's an even number of stones, it seems like
you have to use solid Booleans. I don't know how practical it would
be, but could you put in a option for a distant limit to Curve Booleans
subtract from solids? So for instance, if the band was 2 mm thick,
that I'd want the curve to cut 3 mm deep, so it punches out a hole on
one side of the ring, but not the other.

If you don't mind, I'll send you my tutorials before I add the text,
so you can point out if there's an easier way to accomplish
something...and if you happen to notice something in the ones
I've already posted, don't don't hesitate to let me know...

MoI already allows me to do a lot of things faster, so if I can learn
even more efficient techniques, that's even better!

Jesse

Hi Jesse,
very good tutorial, where did you get the stone mesh from?
regards Tim.

ps iI also have a question about how to make the square offset prongs you did some time ago, I have a way to do them by making a pyramid with Network and then moving across decreasing layers of control points but it is very tedious . I tried to construct from one square to another offset square but it was a pain getting the s shaped uprights to fit and be smooth

regards Tim.

Hi Tim,

Thanks...I'm not sure where the stone mesh came from...I picked out of an old model I had
in my projects folder. Here is a 10 mm version, you can scale it by percentage to get
whatever size you need...so like for a 1 carat, scale it by .65

If I remember correctly...I think the prong is the type you'd make
by blending two curves to get the "S" shape and then
sweeping cross-sections on it.

I drew an arc on the side of the finger circle
where I wanted the prong to start and then a straight line
above the place where I wanted the prong to end and did
a blend curve between them. My angle is little off
on the top square, but this is the general idea.
Also, if you do a G3 blend, it will make smoother
surfaces.

Jesse

Just a little question :)

Thanks Jesse,
I have been using a plain revolved shape , the cut stone looks a lot better.
I don't seem to think of using blend, I will try it out a bit more, ther are so many different ways of doing things , I keep trying to use what I have just learnt!

regards Tim.

Hi Pilou,

You are very observant! :-)


Possibly they made every other one flat so the stone
would look rounder? I don't know.

There are very precise proportions which optimize
the refraction of light in an "Ideal Cut" round diamond.. it's sort of a science.
The Modern Brilliant cut is supposed to be optimized for how light reflects
based on the crystalline structure of the molecules, but most diamond
cutters balance the ideal with economy for all but the best stones..
they are careful not to cut away too much material,
thereby reducing the carat weight and cost to the customer. :-)

http://en.wikipedia.org/wiki/Round_brilliant
http://diamonds.pricescope.com/girdle.asp

A 3D viewer for diamond models
http://www.octonus.com/oct/products/3dcalc/standard/

There are free meshes of gemstones on this site,
http://www.3dlapidary.com/HTML/Collections.htm
but unfortunately they aren't in a format that MoI can open.


Jesse

Hi Jesse,

> I don't know how practical it would be, but could you put in a option for a
> distant limit to Curve Booleans subtract from solids?

This definitely makes sense, but since there is a pretty good workaround of just making solids as cutters, it will probably be a little while before I'm able to schedule time to work on that. One thing I'm not sure about - in solids modelers often times the extrude tool is used for this type of cut, where the extrude can be used to add or remove material from an existing solid instead of creating a brand new object.... I'm not sure which one is best for this option, boolean difference or extrude. Maybe both should have it?


> If you don't mind, I'll send you my tutorials before I add the text,
> so you can point out if there's an easier way to accomplish
> something...

Certainly! But I think it looks like you've got things handled!

But watch out, once you've got fully hooked on MoI you may get grumpy when you need to use other software.... ;)

Your last one really did give a feeling like you've gotten comfortable using things in an optimal way. I guess there can actually be a problem with this in a tutorial because some things like construction lines are so easy to create that they kind of appear somewhat magically in the middle of the tutorial without someone really knowing how they got there. Hopefully this will get addressed when I have some more detailed documentation and additional videos over some specific areas like construction lines. Those will probably round out other tutorials like yours pretty well.

- Michael

Thx for explanations & sites :)

< but unfortunately they aren't in a format that MoI can open.
http://www.3dlapidary.com/HTML/Collections.htm
Curious there are some in 3Dm format
Look at the end of the page many model can be load in 3dm formats but effectively can't be open in Moi

@Michael Why? There are some 3dm format?
These seems for Rhino 2
Can't be open in Moi :(

Hi Pilou, it's because the objects are stored in the .3dm file as a polygon mesh object, not a NURBS object.

MoI will only read NURBS objects out of .3dm files, it skips over polygon mesh objects.

- Michael

Ok ! So 3dm can save 2 different sorts of "curves" minimum (?)
Betrayed by the name :)

> So 3dm can save 2 different sorts of "curves" minimum (?)

Well, the other type of data is not curves, it is a faceted polygon mesh, just triangles and quad polygons like for example what is exported to OBJ format from MoI normally.

There are actually several different types of objects that can be stored in .3dm files, like NURBS, polygon meshes, lights, annotation dimensions, ... MoI will only read out the NURBS objects right now.

- Michael

Hi Michael,

Since you can extract points from the meshes in Rhino, if someone wants to build NURBS surfaces from
the points for some of the more commonly used gemstones, they could. I'll upload some files with points if there's any interest.

Jesse

Edit: I looked at some of the meshes and it seems that unless you work right off the mesh to build surfaces from points, it could be confusing to know which points get connected by lines, so it has to be done in Rhino...I'll do a few of the basic ones.

Hi Jesse - since these shapes are actually intended to be faceted objects, this is one of the few cases where using the "MeshToNurb" command in Rhino will work really well.

To convert it, don't bother with extracting points, just select the mesh stone, run MeshToNurb on it in Rhino, and export the resulting NURBS model.

This will convert each polygonal face into a (potentially trimmed) NURBS surface.

- Michael

Very cool tutorials Jesse!
Thanks. I learn something new everytime I see your stuff.
Regards,
Ken