Manufacturing

Cadalyst MCAD Tech News #114

5 Feb, 2004 By: Joe Greco


In This Issue:
OneSpace Designer Modeling 2004
- Sketching
- Modeling
- Integrated Collaboration
- Conclusions

Several months ago I reported on CoCreate's OneSpace.net, which I found to be a useful collaboration program for people whose business it is to design products (http://cadalyst.adv100.com/cadalyst/article/articleDetail.j sp?id=84204). At that time I didn't cover another CoCreate program, OneSpace Designer (www.cocreate.com), mainly because it's an independent application. This past week I had the chance to use this 3D CAD application, and here are my opinions.

SKETCHING The backbone behind creating profiles in OneSpace Designer is a technology called 2D CoPilot. It's available for creating circles, rectangles, and polylines. The latter consist of lines and arcs, and the 2D CoPilot provides an easy way to switch back and forth between the two. The 2D CoPilot also lets you automatically snap to key points, infer alignments, and key in precise values simply by typing that number on the keyboard.

In short, the 2D CoPilot makes it easy to input these entities. I'd like to see it also work with the other 2D tools, which include stand-alone arcs and two different types of splines. Though these latter elements are not hard to create, they'd benefit from the 2D CoPilot. What is difficult is editing 2D elements. Whether it's moving a circle or editing a spline, Designer's user interface is both difficult to use and out of date, showing its UNIX-based origins. In fairness, CoCreate is in the process of changing the user interface throughout the program, a project it expects to complete in the next two releases. In areas where changes have already been made, the user interface shines. For instance, when it's necessary to create new workplanes, Designer employs a modern, intuitive user interface.

Users of parametric CAD will notice that the biggest difference in the sketcher is that there are no constraints, which means you can't add any geometric, dimensional, or formula-based constraints (the software can add nonconstraint-based 2D dimensions to a sketch). As in other programs, the idea is to use these profiles as the foundation for 3D operations such as extrude and revolve (which OneSpace Designer calls Turn), however, there is also no relationship between 2D and 3D.

MODELING
Speaking of extruding and revolving, both of these commands feature intuitive dragging techniques to create 3D shapes, but the options are somewhat limited. For example, there's no draft option when extruding. In addition, at times the user interface is inconsistent. When adding features such as fillets (including variable radius fillets) you can dynamically drag to define the object, but other times, like when creating a chamfer, this technique is not available. Once again, this goes back to CoCreate being in the process of updating its user interface across the board. Once 3D parts are created, simply hold down the key and the appropriate mouse button to zoom, pan, and rotate the model.

Compared with other MCAD applications, editing features is done differently in OneSpace Designer, using a method the company calls Dynamic Modeling. There is no history tree; instead, a Structure Browser allows workplanes (along with their related sketches), parts, and other components to be turned on and off. You can also use the Structure Browser to build assemblies by dragging parts into the workspace. Designer gets high marks for not having separate part and assembly modes.

Editing or removing a feature like a fillet is not meant to be done via the Structure Browser, although I wish it were. To accomplish this, I first had to open a set of commands called the Main Task Bar, then select the Modify 3D button, which then opened up another task bar that housed 24 more commands. Once I picked the Modify command, another task bar popped up. Then I selected the fillet and keyed in a new radius, however, the fillet can't be dragged in the same way it was created. Right-clicking on the feature provides access to many of the same functions, which saves steps, but sometimes I found it difficult to select the feature I wanted.

OneSpace Designer provides the ability to directly move, offset, scale, and taper individual faces or entire parts, unlike most other MCAD applications. In addition, added features, such as a fillet on the top edge of a cylinder, update when the diameter of the cylinder is changed. This works because the program automatically considers the fillet a feature. Other geometry, such as the outside faces of a shelled part, must be defined as features if you want them to automatically update when edited. CoCreate believes that this type of editing prevents the "parametric paralysis" that sometimes occurs in traditional MCAD modelers - the infamous "I can't make this change, because a later feature, which is dependent on it, will fail" scenario.

When using the Dynamic Modeling in OneSpace Designer, I found both pluses and minuses. For instance, I created a 10mm diameter cylinder and then rounded its top edge with a 3mm fillet. I then used the Lift Faces command to extend the top planar face outward, thus creating another cylinder. This simple example in Designer took only four steps. In other MCAD programs, I'd first have to create a sketch on that planar face (at least six steps in most programs) and then build the extrusion (at least another three steps).

However, trouble started in Designer when I tried to increase the diameter of the original 10mm cylinder by using the Offset Faces command--the model wouldn't rebuild. I also encountered problems when I tried to delete the second cylinder I built with the Lift Faces command. CoCreate's solution to these problems was not the one I was hoping for, which called for the changing of the design intent. OneSpace Designer also has surfacing capabilities, including lofting, sweeping, filling, and more. Most of these follow antiquated construction conventions that require more steps. For example, when sweeping, the object being swept and the path must intersect, or else unpredictable results occur. In short, most surface construction techniques are available, if you can find them--naming conventions are a bit strange. For instance, to create a surface between a series of parallel curves, most experienced CAD users would look for a Loft or Skin command. Designer has these, but to build this surface, you use the Insert Faces command.

INTEGRATED COLLABORATION
From inside OneSpace Designer, a simple menu pick makes it possible to launch the Meeting Center, described in more detail in my previous review. This makes Designer, along with Alibre Design and ImpactXoft's IX SpeeD, one of the most collaboration-aware 3D design programs.

Working with both OneSpace Designer and OneSpace.net demonstrated how having access to other team members, simply by sending e-mails and instant messages from the OneSpace Meeting Center, made a test project flow more smoothly. Also handy is the ability to make screen shots that automatically pop into the Notes section of the Meeting Center, where they can be marked up. Marking up the model with 3D notes is also possible. This functionality is also present in Alibre Design, but when the model is rotated, the 3D notes disappear.

CONCLUSIONS
If you're looking for a history-based parametric modeling program for mechanical design, OneSpace Designer is not your program. However, if you want a system that gives you more flexibility when making modifications, you should consider OneSpace Designer. Its $6,395 price is in the range of its competitors, which CoCreate says are midrange players - SolidWorks, Solid Edge, Inventor, and so on.

If this type of dynamic modeling appeals to you, another option is the Innovation Suite from IronCAD (www.ironcad.com), which also includes parametric capabilities and a product data management system. Though OneSpace Designer is not your only choice, it's worth a look, especially if you find that parametric programs sometimes lead to editing problems and that you could benefit from integrated collaboration.

AutoCAD Tips!

Lynn Allen

Autodesk Technical Evangelist Lynn Allen guides you through a different AutoCAD feature in every edition of her popular "Circles and Lines" tutorial series. For even more AutoCAD how-to, check out Lynn's quick tips in the Cadalyst Video Gallery. Subscribe to Cadalyst's free Tips & Tools Weekly e-newsletter and we'll notify you every time a new video tip is published. All exclusively from Cadalyst!
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