Tracking the MCAD Enhancements

A few hundred enhancements to a single software application? For some Applications, that number suggests a questionable software release. In mechanical computer-aided design (MCAD), that number is an embarrassment of riches—for users.

One of the many rites of spring are the major new releases of MCAD systems. Spring 2000 was no different. Just about all the Windows-based, $5,000-or-less solids modeling packages went up a rev level.

These mid-range systems pack a plethora of features and functions that rival their premium-priced, mainstream MCAD counterparts. Now more than ever, the differences between mid-range 3D packages and premium-priced 3D systems are becoming negligible.

 

Cadkey 99
Now it doesn't; now it does. Cadkey 99 did not include parametric modeling; now Cadkey Parametrics is an option for integrating parametric definition and editing of feature-based solid models, as shown in this mix of 3D wireframe, freeform solids, and parametric solid models. (Source: Cadkey Corp.)

For the sake of discussion, here are some of the many enhancements in functionality, collaboration, and personal productivity in several of the more popular 3D modelers: Inventor Release 2 from San Rafael-based Autodesk; Cadkey 99 from Cadkey Corp. (Marlborough, MA); SolidWorks from SolidWorks Corp.(Concord, MA), a Dassault Systemes S.A. company; I-DEAS version 8 from SDRC(Milford, OH); Catia, also from Dassault Systemes; and Solid Edge from Unigraphics Solutions, Inc. (Huntsville, AL).

This is not your father's AutoCAD
This is not your father's AutoCAD 
Autodesk shucked off its legacy 2D product, AutoCAD, and legacy 3D product, Mechanical Desktop, in September 1999 with the introduction of Autodesk Inventor, a new mechanical design package. Inventor should be popular with two types of designers: those who design large assemblies, and those who don't like the constraints of parametric design.

So what does Inventor have if not conventional parametric design? It has "adaptive technology," which attempts to anticipate the designer's intent, thereby eschewing parametric-based equations, parameters, dimensions, and the like when defining part shapes. In Inventor, parts are defined by the parts that mate to them; that is, you specify how parts fit together. Inventor then automatically determines the parts' sizes andpositions. This approach defines part relationships directly without order dependency.

To help that design process, you create mechanical designs simply by dragging shapes, such as sketches or parts. These sketches and parts will behave and change in real time depending on their constraint rules. For example, when drawing a line, you need only right-click and drag to change that line to an arc. Likewise, clicking on, then dragging, a part in an assembly lets you see how parts will move in an assembly, based on the part's and the assembly's degrees of freedom.

Release 2 of Inventor sports 200 enhancements. Some of these apply to collaboration: Inventor is now integrated with Microsoft's NetMeeting, which creates a virtual conference room to multiple users who's computers are linked by web technology. Some apply to usability: Sketch Doctor is a designer's support system that diagnoses a model's problems and suggests remedies in natural English (or French, German, or Japanese). (These problems can be sketches that are not closed or that have overlapping lines or vertices.) Other enhancements just make the designer's life easier: a global search-and-replace lets you dynamically replace old parts with new ones.

Talking about parametric design...
In November 1999, Cadkey 99 debuted as an interoperable 2D/3D CAD package that could quickly generate geometry that typically takes longer to build in parametric solid modelers. Supporting that interoperability is a native file format that consists only of geometry (no parametrics, history, or feature definitions).

Interoperability is further aided by Cadkey's ACIS body healing feature, which is a menu pick within Cadkey 99. This function repairs the common problems with imported 3D surfaces and solid models, including missing or duplicate surfaces, bad surface normals, and warped and self-intersecting surfaces. This feature also stitches multiple surfaces into a single sheet or solid body. Another function selectively loosens tolerances in imported geometries, thereby closing the gaps in surfaces and solids.

In addition, Cadkey comes with a healthy set of import/export data translation functions. All of this for $1,995.

 

Sheetmetal Design Module
Sheet metal is in. The Sheetmetal Design module in CATIA Version 5 Release 3, like similar sheet-metal modules in competitive mid-range solids modelers, provides functionality for designing sheet-metal parts using standard materials,bend allowances, and corner treatments, as well as for creating and detailing flat patterns. (Source: Dassault Systemes S.A.)

But spring time showers brought Cadkey catering to the parametric crowd directly. Cadkey Parametrics infuses Cadkey 99 with parametric modeling capabilities. This optional module retails for $1,195 (free to Cadkey Design Suite customers).

Plus ça change...
Along with "150 major customer-driven enhancements and innovations," SolidWorks 2000 has taken several pages from Microsoft's user interface standards. For starters, the pull-down menus in SolidWorks 2000 display only those icons and commands available for a particular design situation. The inapplicable commands are grayed out.

Next, SolidWorks Explorer replicates Windows Explorer, providing not only basic file management functions, but also the familiar tree structure to show the file dependencies of drawings, parts, and assemblies. SolidWorks Explorer includes a where-used tool to locate drawings, parts, and assemblies referenced in SolidWorks files; a tool to edit configurations in an assembly or part file; a preview tool like Windows' Quick View; and a tool to search SolidWorks files for user-defined properties. The SolidWorks Explorer also runs stand alone.

Like Autodesk Inventor, SolidWorks also applies click-and-drag to part design. For instance, the "extend surfaces" command will highlight an active surface and add handles to that surface. By "grabbing" these handles and dragging them—and the attached surface—you can distort the surface into a new shape. Alternatively, you can enter measurements in the Property Manager and the model will update automatically.

SolidWorks 2000 includes full-motion simulations of 3D assemblies to show collisions as well as the minimum distance between moving components in real time. There is also a New Hole Wizard, which automatically generates a hole once you've entered a hole size. All hole types are based on standard bolt and screw sizes, as well as user-defined patterns. This neatly eliminates fumbling around for the Machinery's Handbook.

Creating that ol' team spirit
A sizable portion of SDRC's I-DEAS 8 focuses on collaborative design. For starters, I-DEAS Web Access lets authorized users access I-DEAS product structure data and geometry through a standard web browser. These users—even those outside of engineering—can view thumbnail and detail images of parts, assemblies, and related manufacturing information. Next, I-DEAS 3dDocCom eschews paper-based documents, especially 2D drawing documentation, by letting design partners annotate directly to a solid model of parts or assemblies.

Along with these models, users can create and store "model views," which contain annotation, scaling factors, and viewing directions.

Several model views grouped together define a "view folder," which contains all the information to manufacture the part or assembly. As necessary, model views may be used to automatically generate 2D drawing views in I-DEAS Master Drafting, which provides 3D information in a (traditional) 2D context (and replaces I-DEAS Drafting Detail).

Releases, functions, and feedback, oh my!
Version 5 of Catia has been around for two years now. In April, Dassault Systemes and IBM announced the third release of Catia Version 5 (V5R3). This mostly involved offering five Unix- and mainframe-based Catia 4 modules on Windows-based Catia 5. These modules included tools to capture and reuse corporate design, engineering, and manufacturing rules, standards, and general know-how; to generate designs based on geometry specifications and associated data; to route conveyors, ductworks, raceways, pipes, and other distribution networks; to optimize data representations of mockups to verify mockup designs; and to transition from 2D layouts to 3D design and production.