Dear Michael,

I tried a simple shell, but got a problem below :

It happened to me too a couple times with the shell tool

Hi Lish, it's definitely a bug in Shell - it seems like it got confused on the fillet part and tried to extend the fillet past its regular ends when it shouldn't have. I think it has difficulty in this situation where the base object is made up of just one single smooth closed curve segment.

Shell is generally the most unreliable function in MoI, there are several bugs in it. Unfortunately it is quite difficult for me to fix the bugs, they are deep in the geometry library that I'm using.

I'll be collecting some problem examples over time and I'll send them to the people who make my geometry library, hopefully they should be able to fix them up in a future version but it may take a little while.

You will probably have a greater chance of success if you apply fillets after you do the shell instead of before.

Also in this particular case a workaround is to delete the top face and then shell. That seems to avoid the problem with that fillet.

- Michael

> You will probably have a greater chance of success if you apply fillets after you do the shell instead of before.
> Also in this particular case a workaround is to delete the top face and then shell. That seems to avoid the problem with that fillet.

Hi Michael,

Thanks for your tips.
But I hope you can fix this asap, because shell is one of primary feature for plastic designer and who work with "thin model"

Hi Lish - it's not really up to me, it's up to the people who make the geometry library that I'm using.

I expect that it will get better, but it will likely be a gradual process that will take a while.

If you need to do a lot of work with thin-wall-shell type models, then MoI is not the right tool for that kind of a job, you should be using something that has had more development time spent in that particular area, like SolidWorks, Pro/E, etc...

MoI is not suitable as a replacement for SolidWorks for that kind of industry work.

- Michael

Hi Michael...

OK, I see about the geometry library.
Why you said MoI is not for thin-wall-shell modeling if one day the geometry library will work fine ?
Have you another reason ?

I am still believe we can create a thin wall 3d model using MoI.
In my mind, thin wall model are likes : plastic cover of electronics part ( TV, Laptop, washing machine and many more plastic parts )
Can be also some sheet metal part.

Have you same opinion with me about thin wall model ?

Hi Lish,

> Why you said MoI is not for thin-wall-shell modeling if one day the geometry
> library will work fine ?

I was talking about the current version of MoI, and the versions for the next several years.

I do expect that there will be progress in improving the geometry library, but it will take time before that happens.

In the meantime there are other systems out there that have spent quite a bit more effort in making more complex thin-wall shelling work so if you need to do such modeling now, one of those other programs will work better for that.


> Have you another reason ?

Well, it is also not really one of my goals for MoI to become an exact replacement for already existing systems. I am more interested in developing MoI in new and different areas instead of trying to exactly copy other programs that are already good at what they do.

Sheet metal design, for example - I don't really expect for MoI to really ever be focused on that specific kind of manufacturing work. There are already programs out there that have focused a lot of effort on that area, it just doesn't make sense for me with my very limited amount of development resources to try and duplicate all the features that would be required for sheet metal design.

MoI is simply not going to be the right tool for every single kind of existing CAD / Manufacturing work.

That's why I generally say that if you need something that works exactly like Pro/E or SolidWorks, you should get Pro/E or SolidWorks for that, not MoI.

But that does not mean that MoI is not useful for manufacturing-related work - MoI can be useful in the earlier stages of manufacturing design work where you just want to quickly draw things instead of do a more rigorously planned final design for manufacture.

- Michael

Hi Michael...

>> I was talking about the current version of MoI, and the versions for the next several years.

I do expect that there will be progress in improving the geometry library, but it will take time before that happens.

In the meantime there are other systems out there that have spent quite a bit more effort in making more complex thin-wall shelling work so if you need to do such modeling now, one of those other programs will work better for that.

Great ! I will looking forward when the geometry library work fine. Please let us know...when its ready.


In my opinion, in many cases of create a 3D model MoI is easy of use rather than another CAD software. Yes of course MoI can`t replace all the features of another CAD software. I just hope MoI can be one of solution because easy to use and very affordable. The price of a complex 3D CAD software likes Pro....& SW....can be $5XXX up to $10XXX or more....

So we are hope for your breakthrue solution :-)

Thanks Michael...

Hi Lish,

> Great ! I will looking forward when the geometry library work fine.
> Please let us know...when its ready.

I will! But please realize that I am talking about a time period of years from now, not soon.


> In my opinion, in many cases of create a 3D model MoI is easy of use
> rather than another CAD software.

Yes - that's one of the major features of MoI!

But one of the things that makes this possible is not having a bunch of specialized features, like sheet metal design for example.


> I just hope MoI can be one of solution because easy to use and very affordable.
> The price of a complex 3D CAD software likes Pro....& SW....can be $5XXX up
> to $10XXX or more....

Of course I can understand that $5,000 - $10,000 is a lot of money to spend, so it is natural to want MoI to perform all the same functions for just $195.

But that is not what MoI is about - MoI is much more about doing simple models quickly and easily.

The type of modeling that you were mentioning - final models for plastic covers for TVs, Laptops, Washing machines, and sheet metal parts are just not in this area of "simple models".

You could do some simple concept designs of such things in MoI, but tools like SolidWorks, etc... will have a lot of specialized tools for manufacturing details like ribs, etc... MoI will not have that type of thing anytime soon, it is not really the direction that I think that MoI is heading towards.

MoI makes more sense to be used in the early stage concept designs for such complicated things, not for final manufacturing production.

If you go to the main MoI web page, you can see that I've tried to describe MoI as "3D Modeling for Designers and Artists", not "3D Modeling for Engineers and Manufacturing".

There is some cross-over since as a NURBS modeler MoI is able to create CAD data that can be sent to manufacturing systems, but it is not something that you would use as a full replacement for such systems except if you have pretty modest requirements.

You might want to look at Alibre - they are focused more on this kind of mission of a reduced-cost type SolidWorks.

- Michael

Does Moi have the same geometry library as Alias Studio Tools, Rhino....Does that mean that can be as accurate as Studio Tools...

THX

Hi yannada - MoI uses the Solids++ geometry library. This is not the same one used by Alias or Rhino.

All of these engines are based off of the same basic type of NURBS math though, so I wouldn't say any particular one is any more globally "accurate" than any other. They can all contain accurate shapes in them.

Each engine tends to have strengths in the calculation of different particular areas though - one of Solids++ strengths is in boolean operations.

- Michael

Micheal thanks for the link, I been doing some light reading and it all makes sense to me now.

My favorite bit > (in 1998 IntegrityWare, Inc. signed a joint marketing agreement with GeomWare, Inc and Solid Modeling Solutions. The result of this agreement was the beginnings of a new geometric modeling kernel that is a combination of technologies developed by IntegrityWare, Inc. and GeomWare, Inc. Under this agreement all three companies have the rights to market and sell this new kernel. Solid Modeling Solutions, Inc. took the lead in Marketing the kernel under the name "SMLib")

WOW some Very Bright Minds There.

The furure can only be Bright.