So now what is the best way for simulate the best result in Moi ? 6 stars ?

Hi Burr,

> Thanks Danny. I couldnt provide the result because
> i use a version which requires me to pay to export
> out a model. I was going to ask you anyway :o

No Problem, I was familiar with Powershape, I used it at the previous job I had, but then Powershape was using the ACIS kernel, now they're using the Parasolid kernel which I believe they changed to in the past few years. Is that Powershape-e you're using? I read somewhere they brought out a 'pay as you export/translate' software model, pretty cool if you want to learn the software without the outlay and risking trying to download a pirate copy, I think the other vendors like Solidworks and Seimens NX should release something along that model.

Cheers

Hi Michael,

> The N-sided patch result looks really nice!
> No little wiggles or bumps in there.

Yeah, the thing I like about NX's n-sided surface it has a lot of control options to achieve the desired result, not that I use it much in my line of work but hey it's good to know it's there.

-

The Solidworks version is almost identical to the NX version except I noticed the SW version has a looser control point structure, It's possible to tweak the patch further in both software's.

-

Hey Danny,
"""""""""". Is that Powershape-e you're using? """"""""""
Yes... It's very cool to have access to the software. At least they lowered the price for exchange (The cost of using the translator per model). It's something like $79 now.

""""""""""but then Powershape was using the ACIS kernel, now they're using the Parasolid kernel """"""

I think they had a proprietary kindof version (Heavily modified) ACIS. They actually still have BOTH! You can convert between them. You can see me do it in the video. They call it "power surfaces" or something like that... Side note, they even use MESH.

""""""the thing I like about NX's n-sided surface it has a lot of control options to achieve the desired result""""""""

I think thats whats getting the result. But maybe alot of "how to use those" will go along way ;-)

Hi Pilou,

> So now what is the best way for simulate the best result in Moi ? 6 stars ?

The best way is to not do it in MoI - isntead do this particular shape in one of those other CAD programs and then bring the result into MoI.

That will probably be the best way to do it until MoI gets its own n-sided blend tool.

- Michael

Hi Danny,

So in both these cases for NX and SolidWorks, did you have to manually delete the "default fillet" star-structured corner and then construct the n-sided patch as a separate step? Is there no way for the initial filleting to make n-sided corner patches from the start?


Although the SolidWorks generated n-sided patch is not lumpy, it also looks to be significantly not G1 at its connection to the boundary surfaces, I think it's actually too light and maybe needs to have parameters fiddled with to give it more control points to work with in order to hug the boundary's normals better.



- Michael

>The best way is to not do it in MoI - isntead do this particular shape in one of those other CAD programs and then bring the result into MoI.

> That will probably be the best way to do it until MoI gets its own n-sided blend tool.

Cool! For the V3 ?
So wait and see and take some rucksacks against suitcases for travel around the world :)

Hi Pilou,

> Cool! For the V3 ?

I hope so!

- Michael

> Although the SolidWorks generated n-sided patch is not lumpy, it also looks to be significantly not G1 at its connection to the boundary surfaces,

So, if a fairer patch could be made by the library guys (like unto) SW's version, which seems to sacrifice edge accuracy for lumpiness, could there be a way to 'brute-force' G1 to the seams, or some kind of 'adequate' matching? Which will no doubt add new lumpiness...

Okay, I know that the N-sided patch is revealing itself to be a tall and perhaps implausible task, but does the 'star' or 'single skin' method look reasonably better at only three or four sides compared to six? I certainly run into three and four sided spaces more that I'd like, and even the 'star' solution would work better than some of the hackneyed 1-to-1 blend schemes I have to come up with. :-/

Yep, Pilou, these 'other' apps are wayyyy out of my price range, so it's not a solution I can use.

@Mike
Someone speak to me for another one! ;) Any idea of the price ! But surely not cheap :)
KeyCreator(old CADKEY)

http://www.kubotekusa.com/products/keycreator.html

Hi Mike,

> but does the 'star' or 'single skin' method look reasonably better at only three or four sides compared to six?

Well, it will tend to have only 3 or 4 lumps in it rather than 6 lumps in it... I'm not sure if that qualifies for "reasonably better" or not though.

It's fairly difficult to talk about such things in the abstract as the devil is in the details - certainly something that is almost planar already and very regularly shaped will be easier to fill in with any method. Do you have a particular three or four side hole that you would like to test with?

- Michael

Hi Michael,

> So in both these cases for NX and SolidWorks,
> did you have to manually delete the "default fillet"
> star-structured corner and then construct the
> n-sided patch as a separate step? Is there no
> way for the initial filleting to make n-sided corner
> patches from the start?

Yep, I had to delete the star-structure the default filleter doesn't handle n-sided patch that's a seperate feature, NX call it 'n-sided surface' and SW call it a 'boundry surface'

> I think it's actually too light and maybe needs
> to have parameters fiddled with to give it more
> control points to work with in order to hug the
> boundary's normals better.

I'm not a Solidworks expert, I did use a mates seat of the software so I'm not sure how much further it can go, if you like I could have another look.

-

Hi Danny,

> Yep, I had to delete the star-structure the default filleter doesn't handle n-sided patch
> that's a seperate feature, NX call it 'n-sided surface' and SW call it a 'boundry surface'

Hmmm, well that's an interesting difference from ACIS which does an n-sided blend as the default corner making method in the filleter...

Neither kernel really does quite exactly what I'd really like which is an n-sided blend in the filleter but with a good quality NURBS surface result.


> if you like I could have another look.

No, that's not necessary, thanks.

- Michael

ViaCad is switching to a "surface cover" they call it. I think the difference between the more expensive ones, is that ViaCad is not giving control over the degree of the generated cover. The control points get generated the UV, but are very sparse where they need to "Warp". It seems ViaCads follow an "IsoCurve"type of pattern where the others create a nice, full grid and drape as necessary. The ones that trim at the boundry need to extend and twist way out in space to generate the surface, but the sparse points become wrinkles on the nurbs surface.

Maybe Blowlamp can point this to Tim to look at. Control over the UV degree may get a better NURBS out of ViaCad.

Hello,

Interesting result from VSR MultiBlend, to the right. Middle is the NX example, SW the left.

Hi OSTexo,

VSR?? is that Rhino?

-

Hi OSTexo, can you please post the 3DM file of the VSR one? It would be interesting to see if it has any star-like wavy pattern on it or not.

- Michael

It's fascinating how the different software tries to tackle this problem.

In ViaCAD Pro there's a tool to Untrim a surface. So after converting a solid of this test part into surfaces (which remember destroys the original integrity of the nice ACIS produced patch), I Untrimmed this patch and like BurrMan did, switched on control points.

The result is in the picture which to my eyes looks a mess and surely not what I would expect ACIS to produce.
A 3dm file version is also attached.

I hope this discussion helps Michael to engineer a good solution from it all ;)

 

Martin (2).

Hello,

Yes, it's Rhino with the VSR Shape Modeling 2.0 plugin. The plugin is twice the cost of Rhino, but it's paid for itself a few times over with its version 1.1 capability alone. The Multiblend feature is new in 2.0, I thought I'd give it a try. I'm sure that surface can be tweaked to be even better with VSR by someone who actually understands surfacing concepts. Here is the 3dm.