Direct vs History based modelling

[Anonymous]

There is another thread going with this sort of conversation but that thread is more to do with history based modelling than direct modelling.

I find this topic very interesting and have had this conversation a number of times with no real conclusion.

I would be forever grateful if somebody could give an example of how history based modelling is needed from a mechanical engineering point of view.

Ideally what I would like is a solid example, such as if a person was designing a mechanical device how changing something downstream would not be possible with direct modelling, or some other example please?

[cekuhnen]

@O.Tan

I don't think that DM and Timeline will change much. Sofar to be honest I never worked with one system that was perfect.

I used Cobalt as well as Alias and their unique workflows.

The DM in SE looks interesting and I am sure it is good but I am sure also that system has its problems.

If the DM in Fusion could get the ability to add dimensions to a model like a filet size or length of an edge I think that would

be to be honest amazing. But for every other type of work I do DM would be a drastic more time then the TL.

I would be back in Rhino land. "Claas please change this - OK I will have to unstitch all those surfaces, untrim the surfaces .... and stitch stuff back."

In Fusion that would be "Click adjust done"!

I know that Phil does not use the TL and is a DM fan and Jeff is a TL fan. At the end it really comes down to what type of object you are working on.

I know that the feature stack in SW works different and how sketches and such are ordered while the timeline is a strict linear recording of parts.

I can see the appeal of being able to see how features are added to a part something many SW users state.

Yet in the timeline you can show the features in colors as part of their components so for me similar visual thing.

Fusion isn't even a finished product. SE ProE SW have a lot more time under their belt. So one has to keep that in mind.

To my understand this year the sketch engine gets some more attention and after that surface/solid modeling tools will make sense together enhanced.

Colin just mentioned that UV controls are coming to Fusion soon allowing users to map the UV directions better.

This for sure will for example help in furniture design doing proper veneer texturing.

So lets see what will come to DM and TL and modeling tools in the next 1 to 2 years.

[O.Tan]

Yeah, no system is perfect but a good workflow does aid in areas where there's shortcomings, that's the whole purpose of what SolidEdge calls Synchronous Technology (a mixture of DM, TL, 3D PMI and 3D Constraints)

Yup, I realised now that for Industrial Designers like you, the way how Fusion made TL works really well since every command is recorded whereas even traditional history based modeller doesn't do that, however for people like me who does Machine Design, Fusion TL is more messy and error prone then traditional history based modeller.

Have you checked SolidSmack latest article on OnShape? http://www.solidsmack.com/cad/onshape-context-assembly-design-unlike-anything-youve-ever-seen/

It seems the folks at OnShape has figured out a real neat solution to the problem of referenced sketches.

[PhilProcarioJr]

@cekuhnen

"I know that Phil does not use the TL"

I use the timeline everyday at the Forge I work for, but that is all less then 20 part assemblies for which the timeline is fine.

My personal work involves thousands of parts assemblies and a massive amount of changes, design iterations and tons of T-Spline work.  The timeline makes no sense what-so-ever for that kind of work. T-Splines are not parametric so any major changes to a T-Spline model in timeline "WILL" break features in the timeline that are linked to the T-Spline work and I don't care how good or knowledgeable you are. There is no way the work I am doing could be done in the current Fusion with the timeline active (Fusion can't handle it) and I challenge anyone to try and see what happens.

Like I said before depends on your use case which is better. As to which is faster...that also depends on what your modeling. 

I think your missing the point that people are trying to make here...the point isn't that Fusion should be as feature rich as SolidEdge is right now, it's that the Fusion team should have some sort of plans to further expand Fusion's DM capabilities and some tools and features we would like to see if that happens.

[cekuhnen]

@PhilProcarioJr LOL sorry I did mean AD Phil Eichmiller.

I understand the idea about DM Phil. I get it and I agree. Thing is that they AD explained they tried it did not like the overall outcome

and then went with what we have today - a plain DM and a TM mode. 

That's what I said lets see how they will further improve them. I don't really think that the DM system is finished. But before adv surface

tools will make sense other areas need some enhancements like the sketch engine which is scheduled for this year to see some work.

@O.Tan

Isn't in-context the same in Fusion when using 3D include or project between components?

https://drive.google.com/file/d/0Byzv_NlyKp_2eThrYTduRjlHaFU/view

[PhilProcarioJr]

@cekuhnen

Sadly I think DM and T-Splines are not going to change over the next few years....there just isn't enough people voicing that train of thought.

The worst part is all the old school train of thought fighting change. The best solution is a hybrid DM and timeline...one where both exist without a user even knowing it's there that adds to creative design and exploration, and not the current hybrid we have now in Fusion. When hybrid modeling (Solid and Surface to get the end model) first came out everyone fought it, now it's very common and well received because it is better and faster and produces nicer more accurate results. People need to look to the future and leave the old school crap behind.....

This is one of the reasons I am seriously considering buying Evolve...it lets me be creative and productive at the same time without tying my hands together. I can get designs with tons of iterations done very quickly. I also don't have to worry about what type of model I am using...again allowing me to be free of the constraints of current CAD systems. A good CAD system allows you to do design and engineering in the same app. The second one favors the other something is going to suffer.

[cekuhnen]

@PhilProcarioJr

"there just isn't enough people voicing that train of thought."

I am not sure about that actually. I think they know where it currently squeaks.

But I have to agree with @promm that the sketch engine needs to get attention first

since surface or solids are based on them.

[O.Tan]

@cekuhnen 

Isn't in-context the same in Fusion when using 3D include or project between components?

Yes, this feature is nothing new as any mechanical CAD software will have it, the only difference is that how it handles when an object that's referenced to another object is moved. Traditionally the software will just throw an error and the designer will have to fix it but it seems Onshape has a solution for this. 

Thankfully SolidSmack explained it better then I could

But there are valid reasons why people don’t want to use in-context design in traditional CAD software. Some companies actually ban it or require all reference be destroyed. Why? Simply put, errors, and the potential cost of those errors. The worst case scenario of in-context assembly design is when a part changes and that change trickles down through designs, drawings and manufactured parts. We may not even see an error in the assembly. But then there’s when we do get those errors; when the assembly just blows up with rebuild errors, missing references or corrupt design files. In traditional CAD, you’ll see this effect immediately when you move an in-context part in an assembly. We should flippin’ be able to move parts in an assembly without affecting their features!

[PhilProcarioJr]

@cekuhnen

"But I have to agree with @promm that the sketch engine needs to get attention first

since surface or solids are based on them."

I don't mean to sound harsh, but that should have been their first priority 3 years ago since everything in this app is built on it. The reality is, here we are 3 years later with a sketch engine that has a lot of problems.....This falls back to what I have been saying for over a year...stop adding new stuff that's built on a shaky foundation...fix the foundation first.

I love Fusion and the team has pulled off some fantastic things and I don't want to take away from that, but there are some major areas of the core that need some serious work and I hope for all of our sake they focus on the right areas to make Fusion a top notch app that it easily could be. Right now I wish I could say I felt they are going to but sadly I don't think they will anytime soon.

[cekuhnen]

@O.Tan

The thing is the most important tool and feature in a CAD system is still and will remain the human brain and operator 😉

No matter how crazy cool tools you have there are always ways to break em.

My students that went to GM got first everything I taught untaught.

And then GM taught them how they want them to do things workflow wise just to make sure that they create designs in a way

that everybody else will be able to read instantly and work with.