triangle mesh slice intersects itself: created in maya, scaled in repg

[Michael Shiloh]

I've seen this happen a couple of times but now I have one in my hand to
experiment with:

Item created by a student in Maya, and exported as STL. He's done other
objects that have not had this error so we believe the plugin is
installed correctly and the process works.

I load the object into RepG. If I print it as it is (too small), there
are no errors.

If I scale it (in RepG) up by a factor of 10, I get many errors of this
sort:

Feb 11, 2012 5:01:27 PM replicatorg.plugin.toolpath.ProgressDialog$3 run
INFO: Warning, the triangle mesh slice intersects itself in
getLoopsFromCorrectMesh in trianglemesh.
Feb 11, 2012 5:01:27 PM replicatorg.plugin.toolpath.ProgressDialog$3 run
INFO: Something will still be printed, but there is no guarantee that it
will be the correct shape.
Feb 11, 2012 5:01:27 PM replicatorg.plugin.toolpath.ProgressDialog$3 run
INFO: Once the gcode is saved, you should check over the layer with a z of:
Feb 11, 2012 5:01:27 PM replicatorg.plugin.toolpath.ProgressDialog$3 run
INFO: 3.78

Any ideas?

-

[Greg Thorstad]

The stl problem has issues but when it is small it does not affect the
slicing, once you scale it up it has to do a calculation where the problem
is and is not sure what to do. Try running the stl thru the Netfabb Cloud
website. It quite often can fix messed up stl files.

Sometimes changing the layer height will change whether there is an
error/warning as well. If the top of a slice ends up in a different height
then it changes the calculations that have to be done and may or may not
generate an error or warning.

Greg Thorstad, B. Comm.
Thorstad Computer/Thor3d.ca/Canadian Makerbot Distributor
Box 268
Outlook, SK
S0L 2N0
306 867-9596

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[Greg Thorstad]

I should have said the stl probably has issues.

[Gian Pablo]

Yes, I've seen this happen. Basically the STL might have small gaps or errors, but they are smaller than the layer height and are missed. When you scale in RepG, the errors are enlarged as well.

What worked well for me was doing an automatic repair in Netfabb *before* scaling up.

[Michael Shiloh]

Thanks Greg and Gian Pablo. Running through Netfabb Cloud website fixed
my problem on at least the one object I tried.

I'll have my students do this and verify in RepG before I even try to print.

Now to tackle the scaling issue!

Michael

--
Michael Shiloh
Artist, designer, tinkerer, teacher, geek
KA6RCQ
www.teachmetomake.com
teachmetomake.wordpress.com
http://groups.google.com/group/teach-me-to-make