Design of the times

The first major release of Unigraphics NX software to come from the merger of UG and SDRC offers many intelligent features, plus new interface technology. Charles Clarke reports.

CAD users around the world will be relieved to hear that the latest release from the UG/SDRC merger will not leave them stranded in unfamiliar territory.

With the introduction of Unigraphics NX, considerable time and effort has gone into ensuring that the software is a viable new platform rather than just a combination of UG and Master Series. There is new functionality, new interface technology and with the Teamcenter (PDM) product line it provides a well-rounded springboard for EDS’s PLM solution.

The interface consists of a fully customisable web page that gives animated hints and tips to familiarise users with the features. To the right-hand side, for instance, rather than traditional pull-down menus there is a fly-out palette called the resource bar to control NX functions. The bar is consistent across all applications and provides quick access to commonly-used functions like parts templates, drawings, assemblies, even specific set-ups for use with the UG/Studio rendering modules. It contains a history palette, which shows recently accessed data like standard parts.

The templates in the bar are XML-based, which allows easy customisation and integration. They also conform to company standards and carry ‘knowledge’ of their purpose. For example, dragging a part template into a blank window will open a new part with your own or your firm’s preferences active.

Dragging that same part template on to an already open part creates anassembly. This ‘value add’ aspect, which was not in UG or Master Series, has been developed by looking at what the ‘best of the best’ were doing and evaluating what was needed by talking to their customers.

With NX there is a strong trend to make the software do the work. Master Series was renowned for reducing the level of user interaction with every release, and this development ethic has been inherited. Some functions have reduced 20 mouse clicks to two or three and it is easier to work with.

Drawing templates are similarly intelligent. They are set up as standard drawing types, with ’empty’ views in place. You generate the drawing by dragging the appropriate template into the part or assembly window. NX generates the ‘base’ drawing conforming to the template and includes all relevant data such as dimensions and any model-based annotation.

There are also standard component libraries (from UG and external partners) containing intelligent parts that can be used in the same way. These can contain knowledge of their function, which makes matings in assemblies painless. For example, if a drive belt is dragged from a catalogue it wraps itself around the appropriate pulleys it finds in the assembly.

With NX feature creation and modification is done within the context of the part, using much more intelligent selection tools – dynamic view transition is just one element inherited from Master Series. There are also new direct modelling tools, which allow dragging-and-dropping of features, such as extrusions and cuts, directly on to the part. When an existing feature is dragged from the resource bar the feature sizes and orients itself as the references are defined.

There is much more direct manipulation of the model through the graphics window rather than the menu structure. Model entities, like work-planes and co-ordinate systems, have handles allowing users to move, position, align and rotate them freely, or according to features already in the model, like edges and axes.

Sketching and drafting tools have been completely revised to provide a new environment in which there is constant visual feedback on the command being worked with, or the profile being sketched. This includes an array of dynamic display and modification facilities for positional and geometric constraints and relationships, dimensions and a dynamic grid snapping feature – as the window is zoomed into, the grid spacing gets finer. These facilities allow the user to create and manipulate constraints more intuitively without having to specifically manage them.

Unigraphics has always had good large/complex assembly navigation facilities dating back to the early involvement of EAI and ProductVision. Now there is a variety of part and assembly navigators available through the resource bar, which allows the user to place reference points, locate geometric and reference entities and applyparametric constraints.

There is also smart context setting, which provides control over how components, or component sets, are filtered within large assemblies. These can be loaded by attributes like supplier, size, material or spatial location so it is possible to locate all the parts relative to the current task, and it provides a much better understanding of the context of the task in hand.

Another aid to understanding is the ability to integrate JT files within UG assemblies. The JT format comes from the Teamcenter visualisation tools and provides a ‘lightweight’ tessellated file format for efficient communication, collaboration and digital mock-up.

It also allows the distribution of very detailed product geometry without the large file size overhead of native models or releasing sensitive confidential information. The ability to import JT data into Unigraphics avoids considerable data translation problems, always assuming suppliers can generate the files.

Knowledge-based engineering has been a feature of Unigraphics development since Version 17, when Knowledge Fusion was introduced. NX extends this capability into an area that EDS is calling design validation, which means designs can be checked against certain rules or criteria. This allows the user to carry out functional simulations and analyses which check for interference or clearance from motion simulation, as well as weight and centre of gravity and assembly or disassembly issues.

Part quality checks are provided by two modules, Check-Mate and Quick Check. Check Mate allows the running of checks on parts, assemblies and drawings. Checks are typically geometry-based and look for small faces or hidden features, which have been removed or masked. More significantly, these checks can be applied to imported data to find problems ‘up-front’; so instead of spending hours fixing imported geometry, identified problems can be sent back to the issuing authority to be fixed.

Quick Check allows users to build rules, parameters and design criteria into models as they are developed. Using a Knowledge Fusion wizard, ranges of criteria can be set up to ensure that other users can only modify the base geometry withincertain functional limits. For example, the wall thicknesses of plastic injection moulded parts can be kept within certain ranges.

Once Quick Check rules have been set up the utility runs every time there is a geometry update, so there is constant feedback on the current state of the part.

The final part of Design Validation is called Quick Stack, which provides a kind of tolerance sensitivity analysis. It allows the prediction of variation limits (maxima and minima), and identifies major factors contributing to that variation.

NX is the beginning of a merged product that will eventually replace both Unigraphics and Master Series. There is also an I-DEAS NX product, which is taking I-DEAS users along the same path, intended to converge to a single product in about two more releases. It is evident from NX that the merged development groups are taking the best of each product and wrapping it inside a system that is being developed in recognition of the best of what other developers are doing.

Because of the legacy involvement from UG and Master Series, developers have been at pains to preserve backwards compatibility. There is also interoperability throughout the range of UG, I-DEAS and Solid Edge that others would do well to emulate.

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