Digital Art Zone

I just purchased a 3d printer (Makerbot replicator2) and am trying to get models to print. I can print .obj files in my collection, but for models I’ve created in Carrara and export as obj the software (MakerWare) just gives an error about loading. Yes, STL is the normal format, but MakerWare supports obj and can load (and print) others—just not the ones I’ve created in Carrara.

I’ve sent an email to makerbot, but I thought I’d check here to see if anyone had any ideas. I’ve tried a few different options under export, but nothing has helped yet.

And maybe one of you has a working method for getting models created in Carrara into an obj file for use with MakerWare? Anyone else with money burning a hole in their pocket so badly they had to get a 3d printer?

Hya,

I don’t have a 3d printer (yet) but, if you take one of the obj files that works and bring it into carrara then export it again as an obj file does it still work?

other thing is meshlab will convert stl to obj so I’m guessing it might do it the other way round

or mesh lab will clear up your mesh with it’s clean up tools - eg merge duplicated verticie etc

I used to use anim8or a lot, when you took your mesh and turned it into a subdivision ob ject all the imperfections would show up that you never noticed, so maybe this is happening to you - ie the mesh looks clean but isn’t

Thanks for the response!

head wax - 23 March 2013 12:47 AM

Hya,

I don’t have a 3d printer (yet) but, if you take one of the obj files that works and bring it into carrara then export it again as an obj file does it still work?

That’s an excellent point. I need to try that.

head wax - 23 March 2013 12:47 AM

other thing is meshlab will convert stl to obj so I’m guessing it might do it the other way round

or mesh lab will clear up your mesh with it’s clean up tools - eg merge duplicated verticie etc

IIRC meshlab is windows only. I can run most things in Wine on linux and in a pinch I can setup Windows in a VM, but I really prefer OS X software for this. I’m a long time linux user (remember slack on a floppy?), but at home hardly use linux after getting an iMac.

head wax - 23 March 2013 12:47 AM

I used to use anim8or a lot, when you took your mesh and turned it into a subdivision ob ject all the imperfections would show up that you never noticed, so maybe this is happening to you - ie the mesh looks clean but isn’t

I’ve considered that. What I just tried was a very simple object, but in the extrusion and welding I may have missed something. That has happened to me before (IIRC it showed up when I was doing the UV mapping). I’m not familiar with anima8or, any suggestions on how to check the mesh? I supposed I could UV map it and see if there are artifacts, but any other ideas?

thoromyr - 22 March 2013 06:19 PM

I can print .obj files in my collection, but for models I’ve created in Carrara and export as obj the software (MakerWare) just gives an error about loading.

MakerWare is possibly expecting (in the .obj file) a defined object, or defined group of vertex for the object. Carrara outputs material groups.

Steve athome - 23 March 2013 07:26 AM

thoromyr - 22 March 2013 06:19 PM

I can print .obj files in my collection, but for models I’ve created in Carrara and export as obj the software (MakerWare) just gives an error about loading.

MakerWare is possibly expecting (in the .obj file) a defined object, or defined group of vertex for the object. Carrara outputs material groups.

Thanks for the information! I’m not that knowledgeable about obj format so that helps. I’ll run that by the vendor.

head wax - 23 March 2013 12:47 AM

Hya,

I don’t have a 3d printer (yet) but, if you take one of the obj files that works and bring it into carrara then export it again as an obj file does it still work?

No :(

Steve athome’s suggestion (defined object vs materials groups) may be it. Any ideas for how to get a carrara model into an obj file as a defined object? On OS X? I would try hexagon, but it doesn’t work (“can’t open file ‘/gui/tools/xml’ (error 2: No such file or directory)”).

Re-downloaded and reinstalled hexagon. Loaded object file that was saved by Carrara, re-exported as object file. I made sure a few options were checked (merge identical vertices for example) and it loads perfectly in MakerWare. I’m betting its the limitation steve suggested, but at least I now have a working method for getting my Carrara models printed.

Thanks!

thoromyr - 23 March 2013 08:36 AM

Re-downloaded and reinstalled hexagon. Loaded object file that was saved by Carrara, re-exported as object file. I made sure a few options were checked (merge identical vertices for example) and it loads perfectly in MakerWare. I’m betting its the limitation steve suggested, but at least I now have a working method for getting my Carrara models printed.

Thanks!

So hexagon is working now under current osX?
(sorry for picking the one off-topic thing in this thread to ask a question about)

holly wetcircuit - 23 March 2013 09:11 AM

thoromyr - 23 March 2013 08:36 AM

Re-downloaded and reinstalled hexagon. Loaded object file that was saved by Carrara, re-exported as object file. I made sure a few options were checked (merge identical vertices for example) and it loads perfectly in MakerWare. I’m betting its the limitation steve suggested, but at least I now have a working method for getting my Carrara models printed.

Thanks!

So hexagon is working now under current osX?
(sorry for picking the one off-topic thing in this thread to ask a question about)

Not a problem. I’d meant to be explicit about it. I thought I’d already tried reinstalling, but just to be sure what I did was reset the hexagon download and installed. Didn’t even remember to uninstall the old one first. It wanted the serial number and that was it—good to go. I’m running OS X 10.8.2 and Daz doesn’t sign their installers so I had to right click, select open and confirm that in the dialog. Other than that no issue.

Admittedly, all I did was load the obj file and re-export it, but it certainly cleared up the missing file error.

Hi,

you could export the mesh as “daz collada” and use MeshLab to convert it to STL. Advantage of this workflow is that MeshLab gives you a great impression over errors in the model that may lead to unexpected (but predictable) printing problems. The “side step” through MeshLab only takes a couple of seconds but creates a STL file that should run perfectly on just about any 3d-hardware (including CNC, resin based machines etc).

Gust

timlemi - 31 March 2013 03:34 AM

Hi,

you could export the mesh as “daz collada” and use MeshLab to convert it to STL. Advantage of this workflow is that MeshLab gives you a great impression over errors in the model that may lead to unexpected (but predictable) printing problems. The “side step” through MeshLab only takes a couple of seconds but creates a STL file that should run perfectly on just about any 3d-hardware (including CNC, resin based machines etc).

Gust

For some reason I’d gotten the impression that meshlab was Windows only. I’ve downloaded that now, thanks!

For what its worth the workflow I’d come up with was this:

1. export Carrara model as .obj, uncheck swap y/z
2. import obj into hexagon, with:
  - import scale factor of 1
  - unit of file is ‘in’
  - check ‘remove duplicate points’
3. export as stl with default options
4. open in netfabb
5. check for errors
6. use stl

netfabb was recommended by makerbot. The software is okay, but not particularly good and seems geared to pushing the user to pay for the pro version by having an only partially functional free version. By partially functional I mean it does not actually have all the functions claimed for the free version—I don’t expect the free version to have all the functionality of the pro version.

It does seem reliable in flagging files for having errors, however. I haven’t had any trouble with objects it indicates are error free.

Using netfabb’s web app to correct problematic stl files works very well, but requires sending them the file. They explicitly retain the file for a period of time after the conversion and reserve rights with respect to what you have uploaded so that might not be the best option.

To be honest, I’m not particularly confident of Carrara’s Collada export. Just to try meshlab real quick, I tried importing various obj files into it. It doesn’t like Carrara’s obj files—I guess I shouldn’t be surprised—and gives errors on those saved from Hexagon though the files load. For what its worth I took a problematic mesh through Meshlab and it warned about materials but nothing else. The exported STL still has issues (duplicate points, IIRC, netfabb doesn’t say what is wrong).

Granted, the above was done using obj files, not Collada exported from Carrara, but it looks like any repair would be a manual process and, unless you already knew what the problem was, would entail selecting every possible repair. Still, an alternative to netfabb. A shame it doesn’t provide a mechanism for automatically evaluating a mesh as having problems and fixing those problems (which is what netfabb is supposed to do).

Of course, that is an immediate impression of meshlab—I haven’t read any docs or thoroughly explored its capabilities. It looks like it will be a nice addition to the toolbox, thanks!

MeshLab does have quite some repair functions, although handling this tool requires a fifth degre both in rocket science AND cookie baking, but in my experience I always was faster off with fixing the object in the first place ... I haven’t come across a single problem in 3d-printing or in MeshLab that wasn’t caused by poorly constructed meshes.

timlemi - 31 March 2013 07:35 AM

MeshLab does have quite some repair functions, although handling this tool requires a fifth degre both in rocket science AND cookie baking, but in my experience I always was faster off with fixing the object in the first place ... I haven’t come across a single problem in 3d-printing or in MeshLab that wasn’t caused by poorly constructed meshes.

Certainly. I’m no expert at modeling and I don’t know how/why some issues occurred in meshes I’ve created, but it has always been faulty mesh (e.g., duplicate vertices, flipped normals). But just because I’m not a particularly good modeler doesn’t mean I’ll let that stop me from printing models.

To that end, having a workflow that allows detection of flaws is a good thing. I’d rather have identification than simple detection, but with what I outlined some of the issues I’ve found to be common (duplicate vertices) get eliminated in the process of creating the STL file. And running a check with netfabb reveals issues that don’t otherwise show up until printing, so it is a worthwhile step as well.

In the long term I certainly hope to learn more about modeling and how to avoid some of the issues.

2 ideas, if you have not already tried them ...

- in OBJ Export dialog box, choose “NONE” for materials. This will eliminate the material coords from the OBJ file which might confuse the Makerbot software?

- Export the object as an OBJ, and reimport it using “Facet Meshes” option (instead of default “Vertex Primitive”) Export again as an OBJ. Perhaps changing how the vertices are defined in Carrara might make the OBJ readable in Makerbot?

cdordoni - 02 April 2013 01:06 PM

2 ideas, if you have not already tried them ...

- in OBJ Export dialog box, choose “NONE” for materials. This will eliminate the material coords from the OBJ file which might confuse the Makerbot software?

I’m pretty sure I already tried that, but I get a chance I’ll make sure of it

cdordoni - 02 April 2013 01:06 PM

- Export the object as an OBJ, and reimport it using “Facet Meshes” option (instead of default “Vertex Primitive”) Export again as an OBJ. Perhaps changing how the vertices are defined in Carrara might make the OBJ readable in Makerbot?

Interesting idea. I may try that as well, but ultimately if it involves a 2-step I may as well go through Hexagon as that results in an STL file which can be analyzed.

HI Thoromyr

This is curious,. because,. I’ve been using Carrara to export OBJ files,. then upload them to Shapeways for printing,. and,.. while shapeways doesn’t have a specific application listing for Carrara, it does have a listing for Hexagon, So,.. by selecting Hex,.. it’ll load and check the Carrara exported OBJ,. (takes about ten minutes to check the mesh is OK), and then it’s ready to select materials and print.

if any mesh errors are detected,. you’ll get an email with an image which highlights the error.

so shapeways on-line model uploading and checking software, handles the Carrara exported OBJ in the same way as a Hexagon exported OBJ.

but the same scenario is causing an error with your printer’s software,..

it’s strange,.. when both applications were originally made by the same company ! you would expect the OBJ export function would create the same model.