Original file OBJ
A file Nurbs was needing for any reasons! Moi to the rescue! :)
And Thanks again Max Smirnov for _ImportObj & _SUbdiv_Beta9





Alas original file format OBJ has no edges welded!
So when SubDiv in MOi! Cool but not very practical for molding! :)


Moi to the rescue!
Export OBJ with Edges Welded!
Then _importOBJ again! ;)



So now SUbdiv can be normal! :)

Wow!

Very cool result! And thank you, that you show the mistrial - it is as well impressive - worth, to show it!

Have a nice evening
Karsten

Hi Pilou,

Very interesting experiment, but not so clear...

Could you please indicate the precise order of the steps you followed ?
If possible, could you post that obj file ?

Usually when i want to play with Max's subDiv, i import low-poly obj meshes,
in order to obtain a smoother nurbs solid or surfaces.

Another workflow that i use in order to get a smoother nurbs from obj is :

1) Import hi-poly obj in 3DCoat and perform and AUTOPO (auto retopology) in order to obatin a low-poly quad mesh
For this step, you can use any other retopology tool, like for example the very good "Instant Meshes"
(http://www.cgchannel.com/2015/11/download-free-auto-retopology-tool-instant-meshes/)

2) Export the low-poly quad obj
3) Import the low-poly into Moi
4) Run Max'subDiv

If i'm not satisfied with the resulting nurbs, then in Moi i follow a manual "reverse engineering" of the nurbs object,
that is I use the nurbs object just as a reference :

1) Slice the nurbs by Projecting straight lines or curves onto it, using the "Project" command with "Mode : Direction"
2) Tune-up the resulting curves by tweaking control points
3) Using the curves with Loft/Sweep/Network in order to recreate the various areas of the original object
4) Blending the different areas

Obviously using this workflow, the final nurbs object differs more or less from the original nurbs object obtained by first step (Max's subDiv),
but when the precision is not a crucial point, in this way i get a final nurbs object made by a much lower amount of control points,
and made by bigger surface patches.

Nice night!

- Marco (mkdm)

Hi Pilou, I am glad that this worked for you but just keep in mind that NURBS solids are not really designed to be made up of many thousands of little faceted pieces like that, so you may run into problems like extremely large file sizes and operations taking a long long time, things like that.

It's something that you could use for special circumstances but in general you would be better off keeping data like that as polygons rather than trying to turn it into NURBS.

- Michael

Frenchy, Can you give the reason that you need this as nurbs?

<< but just keep in mind that NURBS solids are not really designed to be made up of many thousands of little faceted
Sure but how make when you must have a nurbs file as result ?
Tsplines ? (I kow they are free in free Fusion 360 but fusion don't love a such file...or Max Smirnov ? ;)

<< the reason that you need this as nurbs?

The problem was that the molder company has only nurbs format for their material folding engine!
(and even they don't know what was an "OBJ" format! The real world is sometime very astonished)

the other is that the OBJ original was not verified as welded edges! But I discovered that during the process!

So my complete order was

Decimate the original OBJ something like (250 000 --> 50 000) Meshlab (free) or Decimate Master (Zbrush not free)
so it's the new original decimated for all workflows following!

for me that was evident that the edges were welded so i even not verify that! :)

- Import inside Moi (thx Max Smirnov)
- SudDivision inside Moi (thx Max Smirnov)
- Unsuccess of the result - not of the subdivision - due the edges not welded (facettes separared and rounding very cool effect but...)
so...new workflow
- Inside Moi Import Original / Export original as OBJ with welded Edges (Thx Max & Michael)
- New session of Moi
- Inside Moi import this new OBJ "welded"
- SudDivision inside Moi (thx Max Smirnov)
- Success (Head takes less 5 minutes! 5 000 surfaces)
I suppose that for the entiere figurine you must decimate more ! Seems maxi for _subdiv_beta9 is 8 000 faces !
- Export as Step or IEGS (Thx Michael) (formats wanted by the Molder company)

Sorry I can't give the original OBJ but it was a very common file as you can find on the web!
(but verify the weld states of edges! :)

@Marco
I will study your workflow : quadface can of course an advantage! Seems a very cool prog for make quads! :)
(i have also in Zbrush but want not use it for have the same that the third person who will use the max of free program)

About your "reverse engineering" that is very cool but don't forget that I must also make the more simple
for somebody who know nothing about 3D! It's for that i took a relatively big file! 50 000 faces ;)

PS i precise that I made that for a third person who don't know anything about 3D world!
and I had not real contacts: only advises, and teach workflow possible! :)
So he discovers with great pleasure Moi! ;)
I have not yet final real result in metal or other material! :)

Hi Pilou, I would have probably recommended asking some additional questions instead of just only asking about OBJ format alone for sending the polygon data.

Probably STL format would have been good to ask about, for example. It's possible they might have been familiar with that instead.

If not then it might be a good idea to use a different service that is able to use the data in its original triangulated form.

But if it worked for you in this particular case then that's great, however it's sort of trying to nail a square peg into a round hole.

- Michael

No, from that i understand from the third person the molding company don't know really nothing about the OBJ, STL format!
So they want another format! Only nurbs!
That was a new work for them! The first time that they make this sort of thing! (figurines) : it's not 3D Printing just molding!
I don't know what is their normal industrial production!

Hi Pilou, so possibly using a different vendor that has prior experience with doing figurines would be a better approach.

It's possible they will still have problems because what they are receiving is structured very differently from what they are used to receiving even if it is in NURBS form now.

- Michael

Limitation that i have seen in Moi is the number of surfaces with the Max SUbdiv plugin!
(8 000 seems the maximum) Very Speed! less than 3 minutes!

Maybe they have more strong one by their side!
Objective was to send them a nurbs file with edges welded! (not subdivided) :)

File Step was something like 420 megas, a file 3dm 290 megas : with 50 000 faces welded! :)

Frenchy,

The nurbs file created from the obj may still present a problem for a few reasons. Its possible there are now intersecting surfaces, even if there were none in the original polygon model. Also, the number of surfaces as well as very sharp, thin areas can present a problem as well.

Typically, when a nurbs model is required it is due to the type of CAM system used to create the mold. Mold makers will typically refuse a polygonal file, but a straight conversion to nurbs may not be acceptable either.

So situation is blocked! ... ;)

See what they say, maybe they will accept it. :)

But if they do have an issue with it, I hope they will explain specifically what the issue is. Some of these guys don't want to give away any secrets, you know.

Wait & see! :)

Hi everyone,

I'm testing a new particular workflow, to use when I need to explicitly transform a Low-Poly/Low-SDS obj into a Nurbs object.

For this particular case i'm testing two alternatives, one requires Rhino V6 WIP while the other one requires Moi+Max's ImportObj and SubDiv scripts.

Obviously the two strategies produce different results.

Strategy 1.
------------
I will use it mainly when the Low-Poly/Low-SDS obj contains Ngons :

1.A) Import the obj into Rhino V6 WIP

1.B) Run the experimental SubDFromMesh command onto the imported obj.
I use in this case the lowest PatchDensity value, that is two, in order to minimize the number of resulting Nurbs patches.
I'm testing SubDFromMesh with these parameters :
Creases=NO Output=Nurbs PatchDensity=2 ClampKnots=Yes SetPatchName=NO

1.C) Joining the resulting Nurbs patches to obtain a joined surfaces

Strategy 2.
------------
I will use it mainly when the Low-Poly/Low-SDS obj contains only Quad+Tris :

1.A) Import the obj into Moi with Max's ImportObj script

1.B) Run the SubDiv script onto the imported obj


Here's two links of a simple test i made :

The zipped .3dm file : http://take.ms/7CIiP

The Moi's screen cap : http://take.ms/1lllH


Who knows if the experimental SubDFromMesh Rhino V6 command will have a future...


Good experimentation to all and have a nice day!

- Marco (mdkm)

Hi Marco,

thanks for posting your results. Out of curiosity i tested your model with ViaCAD Pro 10 beta and you can see the result in the attached image. It's the blue model in front from ViaCAD's subd to NURBS conversion.

Regards
Stefan

Hi PaQ,

And thank you very much for your suggestions!
I answer here to your post http://moi3d.com/forum/index.php?webtag=MOI&msg=8090.54

> You shouldn't care that much about ngones or tris, just add a subdivision level to your mesh before import/conversion.
>By doing that, you will always end up with a full quad mesh.

Yes, I agree with you but by doing so I certainly will increase the total polygons count, and in my experiments
I'm trying to work with less polygons as possible, in order to obtain the lightest Nurbs objects.
Clearly in relation with the level of details I need for the particular object.
Only if I need I will do a SubDiv step in most detailed area of the object.

> What's important, is to 'hide' as much as you can any vertex that is not connected with 4 edges.
> The surface quality in those 'poles' area will always be a problem (surface continuity problem, or pinch).
> By hiding, I mean avoid to place those vertex where there is a big curvature change.

Also in this case i agree with you. The poles area are always a problem...
In fact in my example this is clearly evident.
But, what do you mean with "hiding" vertexes ?
Could you please be more precise ?

> I have to say that MAX SubDiv script is doing an amazing job in that area, way better than anything I have seen so far.
>It's very obvious in your example, the middle area where 12 edges are connected to one vertex looks much better
> (I would even say perfect) with Max's script than Rhino result.

Yes, Max's SubDiv is amazing in treating this situation!
But I'm testing the SubDFromMesh Rhino V6 command, mainly for two reasons :

1) I have a commercial license of Rhino too and I'd like to make the most of it :)
And I'm also very curious about what McNeel will give us in the long-awaited official V6 version.

2) Max's SubDiv + ImportObj scripts are very slow compared to Rhino, especially with mid-poly obj (> 1000 faces).
(And I have i7 4790K 4.4 Ghz, not a monster but...)
After all Max's SubDiv is Javascript while SubDFromMesh is compiled into Rhino...
And furthermore, I want to test the possible results obtained converting mid/high-poly count Quad+Tris obj into Nurbs,
in order to find a decent workflow to manually produce a simplified Nurbs version of high-patches version.

Anyway, thanks a lot and have a nice day.

- Marco (mkdm)

Hi futagoza (STEFAN),

and thank you for your test.
Very interesting to see what ViaCAD Pro 10 beta ca do...

I will continue to experiment with a decent workflow for "Low-Mid-Poly-SDS to Nurbs" conversion.
Using both automatic and manual operations.

Nice day!

- Marco (mkdm)

You're welcome Marco.

One thing i should mention is that ViaCAD Pro requires their separate product PowerPack Pro, which offers this functionality and much much more. PowerPack Pro is however included in the beta for testing purposes.

Regards
Stefan

Thank you for the clarification, STEFAN.

Nice day,

- Marco (mkdm)