The Challenges of Model Editing in the Multi-CAD World


In today’s world, most engineers and designers are now accustomed to dealing with CAD data created in other CAD systems. With design collaboration with suppliers, partners, and customers being a key component of today’s product design, the use of multiple CAD systems has become the norm.

As a result, companies must become proficient at working with CAD data in multiple formats in order to succeed. Not only must they be able to send and receive data in multiple CAD formats, but also they must be able to quickly get to work on that CAD data without having to rebuild models from scratch or waste too much time fixing data to get clean geometry.

On average, companies use 2.7 different CAD systems internally. Here’s another daunting statistic: nearly half (49%) of companies struggle with importing models created in other CAD tools into their 3D CAD system, and another 59% say modifying imported models from other CAD tools is difficult using their CAD software.

Vital design cycle time is wasted when models must be recreated; yet making changes to those models is also problematic as intelligent features and patterns built in by feature-based CAD authoring systems are often lost once imported into another CAD system. So what is a company to do when navigating through multi-CAD environments?

Nearly half of all product development companies continue to struggle with how best deal with CAD data originating in other CAD systems. Image courtesy of Siemens PLM.

Nearly half of all product development companies continue to struggle with how best deal with CAD data originating in other CAD systems. Image courtesy of Siemens PLM.

During the Q&A portion of a recent webinar, “The Pros and Cons of 3D Modeling Paradigms,” a question was posed to the speakers as to how best to approach making changes to CAD models that were created in a different CAD system. I think the responses are worth sharing as it’s something with which half of all companies continue to struggle.

Brian Thompson, vice president of Creo Product Management at PTC
“It’s pretty obvious that data inoperability between CAD systems has been tried at the feature level, and it’s generally not all that successful, at least not in a robust way. In general, when you take data in from another CAD system, you’re going to get information like assembly structure but for the geometry, you’re going to get just a closed volume, assuming that the data translation for the solid or the geometry came across well. Unless you want to just use your own history-based features to cut geometry out and recreate it from scratch, direct modeling tools are an ideal set of tools to manipulate geometry that’s come in from a CAD system in which you don’t have the features any longer.

It’s a pretty nice approach to be able to move faces, to align faces, to resize analytic geometry, to symmetrically change a model if it looks like it might be symmetric. There’s lots of tools built into most direct modeling environments that will give you great control over geometry regardless of the fact that that geometry had no features when it came over. You can actually use direct modeling tools to really control that geometry in pretty sophisticated ways despite the fact that when you got it, you didn’t get any features at all.”

Dan Staples, vice president of Solid Edge Product Development, Siemens PLM.

“I would just add that I don’t think it is, to be honest, any contest. If you were to be reading data from another system and you could choose to read it into the history-based environment and non-history-based environment, definitely read it into the non-history-based environment. You have much more flexibility and ability to make the changes you want to make.

I would suggest that in fact if you’re a diehard history-based user, but your system supports a non-history sort of mode, that this is where you want to try it. Certainly we’ve seen our users who when they want to get started with, in our case, synchronous technology and they are asking themselves ‘do I want to use it or do I not want to use it?’ Well, by gosh, the first place to use it (direct modeling) is with that imported data, it’s definitely a homerun there.”

Chad Jackson, principal analyst at Lifecycle Insights and a speaker at the webinar, authored a whitepaper that addresses the challenges of working in multi-CAD environments. You can read “Multi-CAD Data, Unified Design” here. To listen to the entire “The Pros and Cons of 3D Modeling Paradigms” webinar, click on this link.

Barb Schmitz

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