Hi Peter,

> I am thinking of reverse engeneering....... an Alias program
> .. Maya does poly to nurbs after all.....???
> It also imports Skp ? what for if you cant use them ?

I don't think this new one has that kind of conversion in it, it seems that you can load polygon objects, but they are a kind of separate object type that can't interact directly with NURBS objects.

So they're more for things like importing a visual reference or something like that and not for actually converting into NURBS geometry.

See this thread on their forum that talks about this:
http://forum.123dapp.com/123d/topics/cannot_extrude_or_fillet_parts_of_an_existing_model


I've heard that Maya does have some kind of function in it for converting sub-d surfaces to NURBS, but it seems that right now the main one that people use for that kind of a thing is the T-splines Rhino plug-in. Also if you use 3DS Max, check out the new nPower converter: http://www.npowersoftware.com/subdtonurbsoverview.htm


I still think it would be cool if the T-splines guys made a simple standalone converter program that could be used for this kind of a conversion without having to buy the entire Rhino + full plug-in combination. Try asking them about that, I've suggested it to them before and maybe if they get enough requests they will cook it up.

Also if you have SolidWorks the T-splines guys have a new plug-in for that as well.

- Michael

I don't test myself but someone say to me that format SAT from 123D to MOI is perfect!
So you can use Free Form or Push Pull / & OR Rotate faces then export to MOI ;)

Hi Petr,

It is here:

http://www.solveering.com/products/products_stl2step.html

The newest version actually works on OBJ instead of just STL.. It converts the poly's to NURBS planes..

It is hit and miss on high polycount models.. Low poly models have worked OK for me.. I had better results with the 1.4 version, but havnt loaded the 1.6 since I changed my OS.. It is a single clcik deploy WPF application, so you may need to be sure you are on windows with the proper .net stuff or something like that..

It's worth a try for what you describe.

Hi Burr,

That sounds fantastic to import some .obj into MoI for modeling reference ...

... but any .obj coming form modo crashs the application :(

Hi PaQ, possibly try triangulating faces first?

Also PaQ, weren't you recently talking about using Rhino some too? In Rhino there is a command called MeshToNurb that will do this (convert each poly face to a flat trimmed plane, not a sub-d conversion).

Just keep in mind that you can end up with an extremely heavy NURBS model with that method, because there is more overhead to how trimming boundaries work in NURBS models - there's stuff like a 3D edge curve, as well as a 2D edge curve, and the curves are actual splines that are created in addition to vertices.

In a poly mesh model, the edges are more lightweight and basically just implied as straight lines connecting each vertex, so it's more efficient with polys to have something like 300,000 edges in a mesh, whereas 300,000 edges in a NURBS b-rep is huge.

Of course since each edge in a NURBS brep is a general spline you can get a whole lot more out of a single edge in NURBS because it can be an actual curved piece of geometry and not just a line between 2 vertices. That's why you can get a complex model in a NURBS brep with something more like 5,000 edges or faces since each individual edge or face describes a bigger curved piece of the model. But by making each surface a little plane and each edge just a line you're basically negating that.

- Michael

Hi Michael,

I havn't decide yet to pushase rhino yet, I'm still using the pl version, and my export/save count is over since a while.
Seems like the 5.0 is coming this year too, so I'll maybe wait a little bit more (900$ is still a little amount of money especially
for an hobby kind of use).

Thanks for the little explanation about the conversion process, the kind of object I want to use is probably a little bit too heavy
to this process.

As for the convertion crash, I'm using a really low triangulate object for testing (2000 tris), without success.
Maybe it's a data precision problem, the log file report this : 'La conversion de la chaîne "0.0173325" en type 'Single' n'est pas valide' (sorry for the french).

Not sure I have to will to debug the problem with the Solveering LLC guys, I even have no idea how expensive is the pro version :S.

 

- Back to the topic :

123D didnt work for my son at all, the viewport manipulation is to weird for him. It was funny to see him bitching about all the popups too :)
MoI is definivelety much better for kids ;)

Hi Paq,
I havnt used the OBJ import yet, but will load it and look too, to see if I notice anything.. But for sure, the app is sensative....

Hi PaQ,

> Maybe it's a data precision problem, the log file report
> this : 'La conversion de la chaîne "0.0173325" en type
> 'Single' n'est pas valide' (sorry for the french).

Probably not precision, but more likely an internationalization bug - you must have a locale set in Windows that uses the comma character as the decimal point separator?

That program is probably expecting then that numeric data should use a comma as the decimal separator, but that's not the case in OBJ files - OBJ use the period as the decimal separator for numeric values.

Try switching your Windows locale setting to English, or possibly just set the decimal separator setting to a period (as shown in this post here: http://moi3d.com/forum/index.php?webtag=MOI&msg=4282.5) and then maybe that other program will work.

If that does work, then that's a bug in that program, it's using a locale-specific number parsing method instead of using a method that will always use the period as the decimal separator.


> 123D didnt work for my son at all, the viewport manipulation
> is to weird for him. It was funny to see him bitching about all
> the popups too :)

I'm not too surprised, it's hardly different from their regular version which is targeted towards mechanical engineers basically...

I bet your son could learn it if he was introduced to it as part of a class instead of just trying to figure it out directly.

- Michael

Hi PAQ,
I just did a test with Hexagon and an OBJ import/conversion with the newer stl2step converter..

I revieved the error also from a default export from Hexagon.. I then did an export and deselected "Export UV's and Export Normals" and the import into stl2step succeeded!



I havnt tested to see if it was one or the other yet, and I dont know what you have in Modo upon export, but you may look at eliminating some of this information from the export to get the model in... :o

Hi PAQ,
It was the "export normals" option.. Without that, the conversion succeeds. My simple test file has 5888 faces in the STEP file and comes in as a solid.

Hi guys,

I give Michael suggestion a try, I was able to go a step further, but now the error is : The index is outside the array bounds (personnal english translation).
I've removed the uv's (didnt help), but I cant discard normal info when doing the export in modo.

I'll give a try with 3dsmax Tuesday at the office.

Thanks for your help.

Hi PAQ,
Here's the OBJ I tested with that had the normals option unchecked in the export.

Also, Michael had mentioned the Integritywares application. You said you have Max and they have a plugin that I believe only costs roughly $200.00

I think it actually makes smooth NURBS surfaces as a result. I have been excited about seeing this crop out in something that we could utilize.. Just hoping at this point. I contacted them about a standalone option, but I dont think they were interested..

I spent several days to test 123D, and in my opinion, it can become a very good companion of MOI.

The good of 123D :
In fact, 123D uses the same engine as Inventor/Fusion, a robust CAD application with an history tree. This means that when you create a feature like a bevel, you can later edit this feature, and the object is remade to reflect the modifications. Moi, on the other hand, doesn't have this tree.
Another very interesting feature of 123D is the ability to push or pull faces of a finished model, a thing that you can't do easily in MOI, even with the "point edition". In the same way, you can at any time rotate faces in 123D.

The bad of 123D :
As a lot of CAD engines, to create a curve, you have first to create a plane, then create your 2D curve on this plane. And 123D doesn't allow you to modifiy these curves in 3D as MOI.
The process to create features as a loft in 123D become very difficult : you have to create numerous planes, then your curves, and so on.
In MOI, on the contrary, the process is efficient, simple, clear, and much more powerful than the one in 123D.

So ? You can obtain best of both worlds : first I create my object in MOI ( without features like bevels that can produce bad models at export ), and then, I can edit them further in 123D, by moving faces (even curved ones) and rotate them as well. In two words, 123D adds a bit of "interactivity" in the process of making an object.

I'm not a fan of Autodesk. In fact, I think it's one of the worst 3D company in the world. But with 123D, they released a powerful and free tool. Even bad companies can do good things sometimes. :)
On the other hand, to say the truth, I'm a big, big fan of MOI, I think this software is a kind of "miracle" in the jungle of heavy, expensive NURBS softwares.

It's clear that 123D isn't able at this time to replace MOI; it can't beat the power and efficiency of MOI, and it is very far from it. But 123D can add some useful functions MOI doesn't have... at this time.
Worth the try in my opinion. :)

Alexis - www.3dsaloon.fr

Hi Alexis, yup that is a good way to look at it.

In MoI the focus is on making it easy to draw something from scratch, and not so focused on adjusting an already created model.

123D is sort of the inverse - it's more clumsy to draw in it, but very convenient to make adjustments to existing models in it (or it would be if they can improve the performance).

So together they could be a good combination!


One thing also to keep in mind is that 123D is focused on generating output for 3D printing and not on making output for rendering programs (like writing OBJ or LWO files for example).

- Michael

i just tried 123d for 4 days, i don't like it.

there is nothing free from autodesk.
that is probably another bloated commercial bag.
just like many products on the market...very few technical innovations and loads of commercial ones
that you never use, but average customer gets the impression that they are getting loads for very little money.
be aware of free offers. we should make great effort in educating people about classical geometry so they can understand
that purchasing load of colourfull buttons is not necessarily what they need. autodesk is after different kind of education!
anyway...this forum is for hard core modellers.

The main problem with this new app, besides the usability issues Michael has mentioned, is the use of "sketches" instead of individual curves, which do not have grouping(and group operations) forced upon them; this and, as already mentioned, 3d curves.

"Spaceclaim", what I use as a companion to MOI(its possible to copy and paste surfaces and curves directly from MOI - SC has native 3DM export), is similar, but does it the right way:

Hi Ambimind, that was really cool when SpaceClaim added in copy/paste support for MoI.

I mentioned to them that it would not be difficult to add in since they already had 3DM support, and it was just a chunk of 3DM data on the clipboard, and they added support for it in the next version that was out just soon after that.

- Michael

And there are a couple of things that make that SpaceClaim edit boxes much less distracting - one big thing is having them positioned as more connected to some geometry in the model rather than trying to have stuff float around with the mouse.

Boxes that float around with every single twitch of the mouse just has such excessive motion.

- Michael