Professional 3D Jewelry with Rhinoceros

Sergio Petronilli Giovanna Migliorelli

Professional 3D Jewelry with Rhinoceros Addressed to all designers using the CAD

www.logis3d.it

Professional 3D Jewelry with Rhinoceros

INDEX

“Professional 3D jewelry with Rhinoceros�

IMPORTANT Readers are invited to send a mail to info@logis3d.it in order to get 3DM files and images used, for all the models explained in the book Ch.

Title

Abstract

00

A brief introduction to 3D modeling in Rhinoceros

In this chapter some core concepts regarding 3D modeling are briefly covered. Then, it follows an overview of Rhinoceros options and settings, any user should know, in order to customize Rhinoceros workspace and speed up the modeling process.

Snapshot

01

Trimmed heart pendant

In this tutorial a trivial example is used to introduce Rhinoceros modeling to the reader and describe the basic workflow to design a jewel.

02

Trimmed daisy pendant

The very first step towards the mastering of Rhinoceros commands and procedures concerns the learning of OSnap (a short hand standing for Snap to objects) and curves, both planar and not. This tutorial introduces some of these concepts.

03

Double curvature daisy shaped pendant

Differently from the previous Tutorial, here we want double curvature surfaces instead of planar ones. As a consequence, linear extrude can help us no longer and we have to turn to new commands. Of course, for almost any project there are many ways to work it out, among which we should possibly choose the fastest and smartest one.

04

Double curvature daisy shaped pendant with planar outer edges

The current Tutorial looks after the previous one, but this time we require the daisy pendant to have planar outer and inner edges. To achieve this purpose, we fall back on _RailRevolve command which creates a revolution surface from given profile and rail curves.

05

Double curvature heart shaped pendant with planar outer edges

This tutorial is quite similar to the previous one in its workflow as well as the commands applied, but it differs in the curves used to define the pendant shape. Bring in mind that the procedure here explained is quite a general one and can be adopted for rather complex polysurfaces.

06

Double curvature heart decorated cross

In this tutorial it is explained how to model a trimmed cross decorated with inner hearts. The workflow takes after Tutorial 5, but here a more complex trim is added.

07

Trimmed ring from Flow command

Whenever it is asked to project a widely trimmed object having either single or double curvature, instead of using CurveUV and Boolean difference, a sly solution is to apply UDT Flow command: if the object resembles a cylinder and therefore has single curvature, you can apply Flow along curve; if the 4

Professional 3D Jewelry with Rhinoceros

object is domed and has double curvature, you should apply Flow along surface. These commands map a set of objects from an origin geometry to a destination geometry: Flow along curve, as its name suggests, requires both the origin and destination geometries to be curves, whereas, Flow along surface requires both the origin and destination geometries to be surfaces.

In this tutorial, it is explained how to model a ring decorated with navette-cut gems. The gem is built from scratch, based on an image of it. Indeed, many times, the artisan is given one or more gems by the customer and the jewel has to be conceived “around them”. As a consequence, the project constraints consist in both the ring size and the given gem geometry and size.

08

Ring with navette-cut gems

09

Ring with central heartcut gem

In this tutorial we probe into the construction of a ring based on a single heart shaped gem. The gem is built from scratch, starting with an image of it. This can be very useful, if a customer asks for a estimate of the final price and we only have an image of the gem.

10

Ring from Sweep1 command, with trimmed oval head

In this tutorial it is explained how to build a variable section shanked ring, endowed with an elliptic head.

To that end, we focus on Rhino Sweep1 command which lets you obtain a 3d surface out of a curve rail and an array of section curves along it. The sections should be either all open or all closed for Sweep1 to work. In addition, if the second condition is met (that is, all sections are closed), Sweep1 shows you each section seam and direction, respectively as a point and a white arrow along the curve.

11

Heart shaped pendant from Sweep2 command

In this tutorial it is introduced command Sweep2 to build a heart shaped pendant. Sweep2 creates a surface starting with two rail curves and an array of section curves. Sections should be either all open or all closed for Sweep2 to work.

12

Wavy ring from Sweep2 command

13

Embossed heart shake pendant

In this tutorial it is explained how to build a ring, whose outer surface reminds of the shape of waves.

We might have used Sweep1, but we wanted more control over the final result and so two rails instead of one is a better choice.

In this Tutorial it is described how to create an embossed heart shaped pendant.

To that purpose, Blend Surface command is applied, resulting in a smooth transition between the outer and the inner level.

14

Square gem decorated ring from Blend command

In this tutorial we learn how to apply commands to blend either curves or surfaces, respectively named Blend and BlendSrf, in order to build a ring. The ring is endowed with top head and forking shank.

15

Contrariè with top head

In this tutorial it explained how to build a contrarié ring, that is a ring whose shank consists in two opposite arms surrounding and fastening the main 5

Professional 3D Jewelry with Rhinoceros

gem. Suppose a brilliant cut gem is given. Suppose the gem has diameter 1 mm. For the ring we want a gem of 14 points, having diameter 3.3 mm long. To obtain it, apply Scale 3D to the starting gem: scaling center placed at (0,0,0), scaling factor set to 3.3 mm.

16

Trimmed ring from Sweep2 command

This tutorial explains how to apply Sweep2 to build a ring according to the following data: 1. diameter size in the Front view 2. overall dimensions 3. ring profile in the Right view;

17

Heart shaped pendant from Flow command

In this tutorial it is described how to project a heart shape pendant, built upon a 3D curve and defined by variable shape sections, with focus on the Flow along curve command. To many extents, Flow along curve can remind us of Sweep1 command. Indeed, the former is by far preferred when the rail consists in a curve with important torsion and therefore it is difficult to orient the section along it as well as it is difficult to conveniently place their seams.

18

Bulgy ring from curve network

In this tutorial we want to project a bulgy ring from given curve network. To this end it is introduced NetworkSrf command. This command can be fairly regarded as the most powerful command as far as surface creation is concerned, since it lets us create surfaces of high complexity, with the optional aid of History Construction (that is, any change in the curves of the network reflects into the final surface).

If compared with Sweep2, NetworkSrf allows the use of more than two rails, involving a higher and more accurate control over the final surface. It is important to remind that the resulting surface always has four edges, some of them possibly of zero length. In addition, as we can later see in this tutorial, if the curve network has closed curves along the first direction, it requires at least three open sections along the second direction.

19

Trilogy ring modeling and rendering with Rhinoceros tools

In this tutorial it is explained how to build one of the most classic ring, that is Trilogy, made up of three brilliant cut gems, usually having the same weight but sometimes consisting in a greater central gem flanked by two smaller ones. Then, it is taught how to carry out rendering, applying basic tools available in Rhinoceros.

20

Ring with griffes

In this tutorial we learn how to build a ring made up of overlapping heads, each surrounding a brilliant cut gem of diameter 4 mm.

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Professional 3D Jewelry with Rhinoceros

21

22

Heart shaped pendant with trims, enamelling or wires

Bulgy ring with wire decoration from Grasshopper

In this tutorial, commands CreateUVCrv and ApplyCrv are introduced. They are applied to achieve three different solutions over the jewel: 1.

Solution 1: the pendant is trimmed according to a given decoration 2. Solution 2: the solid is hollowed with constant depth, for later enamelling 3. Solution 3: the 3D heart shape is used to build a metal wired net; In this tutorial we want to design a bulgy ring from a given curve network, similar to the one explained in Tutorial 18, but endowed with a dynamic wire decoration from Grasshopper plug-in.

23

Trimmed ring with undergallery

In this tutorial we want to design a ring from a given curve network. The ring is then given an undergallery and both the ring outer surface and the under-gallery are decorated with cut-work.

24

Daisy/heart ring from Flow command

In this Tutorial, it is explained how to build a ring, starting with any given top curve: here a daisy and a heart are used but they are just examples. To that end, command Flow is applied. Flow is able to map and optionally adapt either a single object or an array of objects from an origin curve to a destination one. Since we are modeling a ring, it is easy to make out which curves will be used: a straight line as the start curve, the ring circle as the end curve. In the end, the ring is decorated with metal wires.

25

Contarié bracelet with Voronoi cutwork in Grasshopper

In this Tutorial it is explained how to design a contrarié bracelet of size 60 mm x 44 mm and how to decorate it with a Voronoi trim in Grasshopper. In the Front view, draw an ellipse: center at the origin, Horizontal half axis of 30 mm, vertical half axis of 22 mm. From Document properties  Dimensions  Default, set Text height to 2: since we have to measure small distances later in the model, when rather large distances have already been annotated for the ellipse, it is better to have a greater value for the text, to increase and enhance the visibility of all dimensions.

26

Free-form for modeling a ring with resizing of the model

This tutorial explains how to build a ring from a network of curves, and hence how to interactively change its shape falling back on free form modeling tools. In the remainder of the sample, the ring is then hollowed (according to possibly different thickness values, for example, to make stone setting possible) and its shank is resized in order to obtain different measures from the original one, minimizing the head deformation. We want to recall that Network Surface command can work under History construction: this is a remarkable aspect of the command which lets you obtain a wide range of different results, changing basic curves.

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Professional 3D Jewelry with Rhinoceros

27

Ring with gem and cut-work

In this tutorial it is explained how to model a ring decorated with a central rectangular cut gem, surrounded by a row of diamonds. The project constraints include the ring size, the gem size and position, the ring wall thickness which should be suitable for both casting and stone setting. Then, it’s up to the designer’s creativity how to arrange the model. It is very useful to start with a sketch of the ring in order to define both its volume and shape. In this sample, we draw each ring face at a time and then we apply _FilletEdge command to smooth the final solid sharp corners.

28

Daisy shake ring from curve network

In this tutorial it is explained how to build a ring, whose top shape is given by a generic closed curve, a daisy for the current example. The shank is required to exactly interpolate the curve. To that end, we apply NetworkSrf command to a network, whose arrangement reminds of a cobweb, because all the curves along the radial direction end at the same point. As a consequence, the resulting NURBS surface has a singularity there, where the term “singularity” stands for a zero length naked edge.

29

Solitaire ring from square cut gem

In this tutorial it is explained how to build a ring around a given square cut gem. Let’s have a look at which constraints the model has to stick to: 1. Gem shape and size 2. Ring size 3. Shank thickness 4. Ring top shape and volume The first and second constraints are quite important for the final geometry to be defined, whereas on constraints three and four it widely depends the final cost of the ring.

30

Cabochon ring

In this tutorial it is explained how to build a ring around a given cabochon gem. The ring is modeled through a single surface obtained by Network Surface command. With reference to the first image below, let’s have a look at the constraints for the ring surface: 1. The surface should exactly interpolate the gem profile (Curve 3) 2. The surface should exactly interpolate the ring profiles around the finger (Curve 1 and 2) 3. The surface should exactly interpolate the shank profile (Curve 4 and 5) As a consequence, the ring surface ends up to have five outer edges, but we know that any untrimmed NURBS has always a maximum of four edges. Here it is given a procedure to build the ring shape with one and only one surface, with no need to rebuild the bottom of the geometry (to remove singularities), whereas the ring hole is created in a later step. This 8

Professional 3D Jewelry with Rhinoceros

is a convenient compromise to avoid coping with polysurfaces in the early stages of the model being the benefit apparent: a unique surface can be easily deformed by UDT tools (such as FlowAlongSurface or Splop), trims can be applied falling back on CreateUVCrv/ApplyCrv, Squish can be used to create wires and decorations over the object, the cutter for hollowing can be quickly obtained applying Offset Surface to the ring outer geometry.

31

Five gem decorated trimmer ring

In this tutorial we want to model a ring starting with a real jewel, whose photos are given in attachment.

We want the ring to be as similar as possible to the original one, although we suppose the available gems are slightly different in size from the ones in the photos. As you can see, five gems are set into the mounting: a square cut gem in the middle, surrounded by four oval cut gems. At first glance, the procedure might seem awkward to be established, indeed we can divide the ring into its basic components (that is, the shank, the head and the griffes), model them and then merge all applying Booleans in order to get the final result. This “Divide et impera” approach will be of great aid.

32

Ring with central pearl and brilliant cut

In this tutorial it is explained how to build a ring, as it were, around a pearl of given diameter. The shank is then scattered with brilliant cut gems. Suppose the pearl diameter measures 8 mm, whereas the round gem diameter measures 2.1 mm.

33

Band ring with pavé stone setting and bright cut

In this tutorial, a basic ring model is given to explain some traits of stone virtual setting: how to seat the diamonds according to a honeycomb layout (pavé), how to drill the holes, how to secure the diamonds, how to bright cut the metal through a virtual engraver. Due to the simplicity of the basic model, the procedure is quite fast and can be entirely carried out through standard Rhinoceros commands.

Anyway, for either more complex geometries or more sophisticated requirements, it is better to use dedicated plug-ins such as Pavetool, whose trial version can be downloaded at our site www.logis3d.it.

34

Daisy shake pendant from UDT

In this tutorial, we introduce a straight example of organic modeling: the Tutorial focuses on UDT (Universal Deformation Technology) CageEdit command: CageEdit lets you associate any target object, you want to transform, to a control object.

Hence, any change in the control object reflects to 9

Professional 3D Jewelry with Rhinoceros

the target object. At the command line, a minimal set of control objects is given: the user can select any of them but, what’s more, s/he can select her/his own control object in the document (either curve or surface geometries are allowed).

35

Gold locket with decoration from gray scale heightfield

As far as either lockets or pendants are concerned, an interesting technique for decorating them consists in using suitable fonts to obtain gray scale images and then apply Heightfield from image command in order to emboss the plate. Here it follows a more detailed description of the general procedure: 1.

Choose a font and define the curves for the sketch 2.

Enhance the just defined curves: remove self intersections, apply non uniform rebuild within a convenient tolerance, make sure all curves have degree 3 3.

Edit the curves to change the sketch according to your needs 4.

Apply Surface from planar curves command to create surfaces 5.

Create the gray scale image out of the surface either applying _ShowZBuffer command or enabling rendered view and then applying Capture viewport to file 6.

Apply Heightfield from image command to the image 7.

Trim the surface obtained in step (6) 8.

If need, apply UDT tools to modify the maximum height of the surface along Z;

36

Heart shaped ring from network surface

In this tutorial it is explained how to build a heart shaped ring, starting with an image describing the ring from the top. Rhinoceros Network surface command is applied.

37

Heart shaped pendant with decorations from gray scale image

In this tutorial it is explained how to model a heart shaped pendant and, what’s more, how to decorate its outer surface applying gray scale heightfield techniques (based on ZSurf4 plug-in) combined with Rhinoceros UDT (Universal Deformation Technology) Splop tool. In short, the main teaching consists in how to apply possibly complex decorations onto a given object.

38

Extruded ring from background bitmap and pavé setting from Grasshopper

In this tutorial it is explained how to model a ring, starting with two photos of a real sample, respectively taken from the front and the right view.

Once the model is done, a pavé is placed on its outer surface: to that end, Grasshopper plug-in is exploited. Be careful when taking the photos: in order for them to be of use for the project, it is recommended to align the vertical to the plane where the ring object lies.

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Professional 3D Jewelry with Rhinoceros

39

Trimmed pendant with parametric necklace in Grasshopper

In this tutorial it is explained how to model a trimmed pendant. In addition, a parametric necklace is modeled in Grasshopper, to let the designer plan the number of chain links in real time, as well as, their orientation along the necklace itself.

40

Marine chain link with network surface, sweep2, TSplines and texturing of the final surface

In this tutorial it is explained how to project a marine chain link. First a more traditional approach is given, based on Rhinoceros commands such as Network Surface and Sweep2. Then the same model is obtained applying T-Splines technology.

In the end, we focus on how to decorate the model surface through displacement mapping.

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