Again, many thanks for the replies!

@ Pilou: Thanks! I already tried importing the mesh as an obj file and it works perfectly. I was even able to decimate the mesh to about 5-7k polys without losing any details. The model should print out to about 8mm as a physical object, so the final result should still have some pretty fine detailing.

Although, I'm curious about why the stl binary format didn't work.

@ Jim: I emailed my client, but he hasn't replied yet. If he's okay with it, I'll attach the file here asap.

Thanks for the quick replies guys!

@jim said:

NaN in Ruby and some other languages means "Not a Number"

http://stackoverflow.com/questions/19154461/ruby-on-rails-how-to-deal-with-nan

@Frank - Are you really using SketchUp 8, have you tried the latest version of the SketchUp STL Extension, and can you share the .stl file that is causing the problem?

Yeah, I'm still using Sketchup 8. I heard that Make has a different UI, and as I've just gotten the hang of ZBrush (the king of quirky UI's), I think I might lose my sanity if I had relearn Sketchup's navigations again.

BTW, I changed the STL format from binary to ASCII, and was able to import it again. Does that help with narrowing down the problem?

I could share the file, but as the model is something I'm working on for a client, I'm not sure if I'm allowed to do so. At the very least, I'll have to ask for his permission.

I tried exporting a model/mesh I sculpted from ZBrush to Sketchup in stl format, but encountered an error called "exception: NaN." I've never seen this before, and I've been able to import some stl models from ZBrush before this.

I haven't done anything differently that the last few times.

Also, I was able to import the mesh as an obj file, but not stl.

Thanks for any advice.

@d12dozr said:

@skyways128 said:

So, I work in meters and export in mm? Got it.

Nope

Import as meters, work in meters, export in meters...do everything with Sketchup using meters. When you open the model in another app for 3D printing, THEN you import as mm and the scale will be correct.

Whoops! Thanks for the clarification!

So, I work in meters and export in mm? Got it.

Thanks again for all the great help, guys!

@d12dozr said:

If you want the imported model to be watertight, you can set the STL plugin import units to Meters before importing, and then it should work.

And yes, if Netfabb says the model is watertight, you can be assured that it is!

Thanks for the pointers, d12dozr!

There's a dialog box that appears when I import an STL file, which asks if I want to set the units in inches, millimeters, etc, but how to I convert back to millimeters once I'm done checking with solid inspector? I'll need to convert the model back to it's intended measurements for 3d printing.

@box said:

It sounds like you've worked out the answer.
If you are importing small models into SU then it's most likely not forming the little faces.
If you import at a larger scale it will probably remain a solid.
So I wouldn't say Solid Inspector is failing, you are running up against the tiny face problem inherent in Sketchup.
If the vertices that make the faces are around 1mm apart SU can see them as the same point and fail to form the faces.

Hi, Box!

Yeah, that does seem like the case. I remember running into a similar problem with soap skin bubble, before I realized I had to magnify the size of the model up to 100 times for Sketchup to form skins properly. That would explain why Sketchup refused to repair a good number of the small triangles.

The space between some of those triangle holes are as small as 0.1mm! And that's AFTER I resized the model to almost 1000mm!

Well, I'm just glad the model's probably watertight after all.

I've been importing and exporting stl files between Sketchup and ZBrush for a few days now, and I noticed that whenever I export the file back to Sketchup, Solid Inspector (a plugin that checks to see if a model is solid or "water tight") always discovers triangles without faces.

The only things I've done to the model after importing to ZB was simply to make it into a polymesh, Dynamesh to 256 resolution, and then decimate it back to around 20k poly's. I was just testing how many polys Sketchup can handle before it noticeably slows down.

After hopelessly trying to solidify the file with Sketchup plugins, I repaired the stl file in Netfabb Basic (free version), and the status box says there are no holes. But when I import it back to Sketchup, Solid Inspector still finds numerous triangular holes.

I'm beginning to suspect that Sketchup actually failed to generate those faces on the triangles, since the holes didn't appear in Netfabb or ZBrush.

I guess what I'm trying to say is, if Netfabb says there are no holes in the model, should I take it's word for it over Solid Inspector's?

Thanks for any advice.

Got a bit of a problem using Sculpt Tools here, as I'm using Sketchup 8, which I've heard is supposedly incompatible with the plugin. After reading some earlier posts, it seems that I have to uninstall all my plugins and then reinstall them for Sculpt Tools to work.

Thing is, it loads just fine, but it does nothing when I select bulge/smooth/drag whatever. I tried left/right clicking and pressing the arrow keys. It does absolutely nothing.

Am I using it right, or do I have to uninstall and then reinstall my other plugins?

BTW, if I simply cut and pasted all my plugins from the Sketchup folder to a backup folder, installed Sculpt tools and then re-pasted the plugins back into Sketchup plugin folder, would that work?

Thanks in advance for any advice.

Chris and TIG, many thanks for the replies!

As per your advice, I tried up-scaling the model to 1000 times it's actual size, and the empty triangles stopped appearing.

The only leak solid inspector shows now is the open side of the head, which will go away once I mirror the other half of the head and merge them.

Thanks again!