By John E. Wilson
Most popular parametric 3D solid modelers are great for creating models that can be readily modified to meet changing design criteria, but they are not as good at constructing the freeform shapes commonly found on consumer products and automobile bodies. Product designers often use other tools to fill the gap and Rhinoceros, from Robert McNeel & Associates, is one of the most versatile of these. Rhino has been used to successfully design objects ranging from children's pull toys to ocean going yachts. The curving organic shapes that are now commonly used in both exterior and interior building designs are also suitable subjects for Rhino models.
Rhino can create both solid and surface models, but unlike many programs, these models are not different object types. As a result, you can use typical solid modeling techniques, such as a Boolean difference operation, in creating surfaces; and you can use typical surface modeling techniques, such as a two-rail sweep with multiple profiles, in creating solid models. All Rhino curves and surfaces (including the surfaces of solids) are NURBS-based.
Rhino's impressive set of methods for creating surfaces, include edge curves, planar, extrudes, lofts, networks, rail sweeps, revolves, drapes, height fields, blends, and offsets. Once you have created a surface, you can trim, split, move, rotate, scale, fillet, chamfer, and copy it; as well as join it to other surfaces. You can also edit surfaces on a basic level through their control points. Rhino has an equally impressive set of methods for creating and working with curves.
Rhino is intuitive to use, and has a well thought-out, logical interface. You can initiate most actions through either screen pull-down menus, right-click shortcut menus, or tool bars. Unlike most Windows programs, Rhino also has a command line, which is useful for initiating actions, specifying options, and entering point coordinates as a set of three numbers separated by commas (rather than having to tab through separate X, Y, and Z fields in a dialog box). You can also use command line input to create script files and keyboard macros that streamline operations you often perform. Rhino does use dialog boxes when they are applicable.
|A mountaineering helmet designed in Rhino shows the kind of smooth, sculpted shapes the program can handle.|
Image designed with Rhino by Incognito Design studio of Annecy, France.
Typically, you will use multiple viewports as you create Rhino 3D models. These viewports are similar to the operating system windows used in most newer CAD programs in that they are rectangular and you can stretch and move them, but in addition, each viewport can have its own coordinate system and visibility settings. This enables you to more easily use your pointing device in specifying points in 3D space. To help you visualize your models, Rhino supports shaded views and basic renderings.
Often designers use Rhino in conjunction with other programs. To support such partnerships, Rhino offers a vast assortment of file export formats, including IGES, STEP, Autodesk DWG and DXF, ACIS, Parasolid, and STL (for rapid prototyping machines). Furthermore, to ensure compatibility, Rhino has options for saving IGES files in specific flavors for programs such as Dassault Systemes' Catia, PTC's Pro/E, and SolidWorks. For reverse engineering, Rhino supports 3D digitizer input from both Faro Technologies and Immersion Corp.
The primary purpose of Version 2.0 is to add hooks for running external plug-in programs with Rhino. One such plug-in is Fla mingo, an advanced raytracing renderer also from McNeel & Associates. Plug-in programs for marine and other specialized design fields, CAM systems, and utilities are available from third-party sources. Release 2.0 also includes enhancements to Rhino's built-in renderer, and adds new options and capabilities to many tools for creating, analyzing, and modifying curves and surfaces.
One of Rhino's drawbacks is that its tools for creating 2D documentation of 3D models are limited. While you can create top, front, and right-side views of your models, there are no provisions for creating auxiliary or section views. Further more, its dimensioning and annotation tools are basic. As a result, you will most likely export your models to a CAD program when you need 2D drawings of them.
Surface modeling has long had the reputation of being difficult to learn and use, and for requiring high-end platforms and hardware. Rhino, though, belies this reputation. It combines power, ease of use, versatility, and usefulness in a program that carries a modest price tag, and runs on most any computer using a Windows operating system. If you have not yet moved from 2D to 3D, Rhino is an excellent vehicle for making that move; and, if you are currently creating 3D models, especially with one of the parametric 3D solid modelers, Rhino is an excellent choice for extending the capabilities of your program.
John Wilson runs a design and drafting company. He is the author of 3D Modeling in AutoCAD.
Rhinoceros Version 2.0
Price: $895. Upgrade: $295.
Minimum System Requirements: Windows 95/98/ME/XP/NT/2000; Pentium or equivalent; 64MB of RAM; 50MB of disk space
Robert McNeel & Associates