Michael,

I hope its clear from the picture. My model has these strange openings in some of the faces. The object properties displays it as a "solid" though. My question is; will this be a problem for 3dprinting? Is this just a display error?

Just artefacts I suppose ;)

Hi beanworks - those look like they may possibly be some damaged areas of the model, there might be some problems with the trimming boundaries of the surfaces in those particular areas. If a surface's trimming boundary loops around and intersects itself it can make stuff that looks like that - the "inside" and "outside" trimmed regions of the surface become ambiguous when the trim curves are self intersecting and if that's the problem you have then that can also affect 3D printing as well and those areas will need to be reconstructed.

Is it possible for you to post the 3DM model file, or send it to me through e-mail at moi@moi3d.com if you want to keep it private? If you can do that I can then inspect your model more closely to see what is going wrong there.

But those look like it might be something wrong in the geometry.


> The object properties displays it as a "solid" though.

That means that all edges are joined to other edges. But it is still possible for there to be other kinds of problems in a model like surfaces with self-intersecting trimming boundaries, that can make things invalid for 3D printing even though all edges are still joined to one another.

- Michael

Unfortunately, I'm not allowed to send the file. I ended up deleting those faces and replacing them with identical faces using "join". It looks right but the properties indicate that it is now a "joined srf" rather than a solid. How do I turn it back to a solid?

Hi beanworks - that means that some edges in there did not get joined together.

You can see which particular ones are still open by setting up a shortcut key with this script on it:

script: /*Select naked edges*/ var gd = moi.geometryDatabase; gd.deselectAll(); var breps = gd.getObjects().getBreps(); for ( var i = 0; i < breps.length; ++i ) breps.item(i).getNakedEdges().setProperty( 'selected', true );

That's convenient to put on the N key so that when you push N the "naked edges" in the model will highlight - those are the edges that are not joined between 2 different surfaces, and those are the openings that you need to resolve in order to make the object a full solid.

To set up the shortcut key, go to Options> Shortcut keys and push the Add button to add in a new one at the top. For the key part (the left-hand column) put in N and then for the right side command column copy the above script and paste it in.

Then you can push N to see the unjoined edges in your model.

There's maybe some little gap in there or possibly one of the edges that was messed up and causing the problem there before was still in the model since when you deleted one face, the trimming boundary edge that the face shared with the adjacent ones is still there.

It's going to be pretty difficult to help you as well as I could if you could send me the model - is it possible for you to send it to me privately at moi@moi3d.com through e-mail instead of posting it here?

Otherwise, you may need to do some kind of object repair work which is somewhat advanced stuff. There is a tutorial available here that goes over the techniques involved of untrimming and retrimming surfaces though:
http://moi3d.com/forum/index.php?webtag=MOI&msg=446.17

- Michael

Love the script. Thank you for the tips. Worked perfectly