Format conversion with MESHLABS

Dear All,

I only recently heared about Shapeways, and joined yesterday. As an 3D enthusiast (hobby, not profession) I really would like some real 3d versions of my virtual models.

Since I usually generate OBJ or STL files, I was looking for an open source convertor (into COLLADA). I found MESHLABS (meshlabs.sourceforge.net), which can do the job. With MESLABS, besides conversion and scaling, even various modifactions can be done.

So maybe MESHLABS can be an opensource alternative to ACCUTRANS 3D. Myself, I will try and upload an model converted by MESHLABS soon.

Best Regards Hans

Hi Hans,

I've tried MeshLAB, but found that the scaling transformations aren't applied to the Collada exports :-/ (even when you 'freeze' the object). With some luck, we'll have proper STL support later this week though - MeshLAB will definitely be useful for that!

Bart

Hello Bart,

Thanks for your quick response.
(indeed it's MeshLab and not Meshlabs, sorry)

STL support would be great.
OBJ converting in STL is also possible, and it would avoid the "COLLADA hassle".

Looking forward to hear from you, if you got STL support up and running. Thank you.

Hans

We'll let you know, don't worry!

Bart

PS: Oh, and I certainly didn't write 'Meshlab' that way to point out a spelling mistake, but now that I see it back it does look that way. Silly me!

Hello Bart,

Sorry to bother you once more regarding Meshlab.
I did a quick test with Meshlab version 1.1.1 (March 2008).

I started with a simple cube of size 1 (Test_cube.obj)
Next, opened it in Meshlab and converted it into Collada (Test_cube.dae) and closed Meshlab.

Next I opened this dae file in Meshlab and scaled it with factor 8 (freeze/close), and saved it as (Test_cube_size_8.dae) and closed Meshlab again.

Next I opened the scaled dae file in Meshlab and looked at the bounding box, it showed indeed a 8x8x8 size.

Finally I converted Test_cube_size_8.dae into Test_cube_size_8.obj. If I open this obj file in a 3D application, it indeed has size 8x8x8. So for sure this dae file contained some scaling information which was correctly applied to the obj file. But the question remains if the dae file also has size 8x8x8.

Since I can not open a Collada file in my 3D-Applications, can you please check the attached file (Test_cube_size_8.dae) for it's size in your "printing software"?

Thanks in advance. Hans

Hi Hans,

hmmm, odd. I managed to get some fairly decent results by converting from STL to Collada with Meshlab today as well, maybe I did something wrong last time. The easiest way to test is to just upload the model to Shapeways and set it to 'Private' (unless you want your public profile to be filled with cubes). Anyway, that's what I did and I got the following result in the mail:

"The size is 1600 x 1600 x 1600 ( h x b x d)."

It looks like you're almost there, but one Blender unit translates to 1 meter. (A default Blender cube is not 1x1x1, but 2x2x2). So resizing in Meshlab to 0.01 will probably to the trick?

Bart

Ok. Tried scaling my .dae file in MeshLabs. I see the 'Close' .. but for the life of me .. where the heck is the 'Freeze' button? Either I'm crazy (could be) or I got shortchanged a button.

The command you are looking for is in the filters menu: Normals, Curvatures And Orientation->Freeze Current Matrix. There really should be a freeze button since it is used constantly.