A lot of people are finding themselves in the position of looking for a new CAD package these days. The market is stirring itself up, there are new offerings, and the old offerings are just that – old. Not that there’s anything wrong with old. I’m creeping up on it myself.
The first time I saw a demo like this, I flipped. This kind of history-independent power should really be turning some heads. Just to sum it up for you, what it happening in the video below is that you can make features dependent on existing geometry, and then use either the new or old geometry as driving features. No stupid tricks, this is just the way it works. To Solid Edge, it’s just geometry. There is no method to make it, no forced metaphors like baking a recipe, or writing a computer program. It’s just geometry. Think about changing sketches, and that’s the kind of flexibility you have with changing 3D parts in Solid Edge Synchronous Technology.
My last post here talked about Top-Down Design – a big selling point for some CAD software – actually turning out to be a best-practice nightmare. And it is. Besides that, it’s kind of a philosophical brain-bender, but we’ll get to that a little later.
During the years that I’ve worked with CAD, there was one thing that I found that just terrified a lot of users and even CAD managers: In-context design. It’s true that people fear what they don’t understand, and this falls into that category to some extent. The real root of the problem, though, is that people just don’t trust it. And this is one case in which understanding it may make you trust it even less. Like what’s really in a hot dog? It may or may not be appetizing as it is, but knowing what’s in it will certainly not make you feel better about it.
[editor]: This was a post written five years ago about the possibility of using familiar parametric design ideas with history-free models. Here I’m trying to get my head around the idea, and trying to introduce readers to the concept that maybe history-based modeling isn’t the only game in town.
Part 2 is all about the role that the technology played in my switch. Going from a skeptic to a supporter seems like a big jump, but if I explain this right, it will be obvious. The functional differences to me are compelling, especially for the kind of work that the largest group of mid-range CAD users do – machine design, which uses primarily prismatic shapes.
One of the biggest taxes on businesses who are still using history-only CAD is interoperability. If you save a model in version X, you can no longer open it in version X-1. This has correctly been described as a subscription ratchet, that keeps you buying new versions to keep up with your suppliers or customers. You may hear a lot of reasons given for why this is technically necessary, but it boils down to a problem of will – the company just doesn’t have the will to allow you to make your own decisions about when to update your software.
Sometimes I think the Synchronous message gets a little bit garbled. We get so caught up in stressing the strengths of Synchronous Technology and dinging history-based modeling that we tend to forget what we are really promoting is not one method, but a combination of the two. It’s true. History-based modeling has strengths, although they might not be strengths you recognize. To me, the most important strength of history-based modeling is the ability to remember topology that gets eliminated by subsequent features. The most limiting weaknesses of history-based modeling are that the design intent is hard to change and that parent/child relationships make feature failures common, and force the concept of “rebuild time” which users of direct editing methods haven’t even heard of. Read more on Mixing Synchronous and History…
Design intent can be a tricky topic. I’ve heard some people argue that there is no such thing. I myself have tried to rename it “Design For Change”, because I think that makes more sense. In any case, it’s pretty clear that with history-based modeling systems, the best you can say for design intent is that you need to see into the future to establish it, and into the past to use it.
It turns out that Design Intent could be the most powerful aspect of Synchronous Technology. With your typical history-based model, you have to understand how the model was built to understand how it’s gonna react to changes. With Synchronous Technology, you determine the design intent at the time you make the change. Read more on Do You Use a Crystal Ball for Design Intent?…
I think when you understand this kind of flexibility, you will not look back to a history based system, particularly for prismatic parts. It’s not just direct edit, it’s the combination of all the tools including Live Rules, the dimension capabilities, and other things we haven’t looked at yet such as persistent face relations, procedural features, and more.
Take a look at this video for more on the flexibility of Live Rules.
Read more on More Design Intent Flexibility…