Lately I have been getting this STL Export Warning dialog box when I want to export models for 3D printing.
I always click Export Anyway, and the resulting STL is always accepted by Shapeways and prints fine.
The export settings I use are based on Kyle Houchens’ suggestions at http://vimeo.com/80478910 (Time mark in the video at 58:00)
Why is this happening?
Hi Zews - it is possible the objects are not fully closed but Shapeways is being tolerant and closing things up for you as part of their process. Can you post an example here or to tech@mcneel.com?
thanks,
-Pascal
Pascal,
You are right. Once again I seem to be having issues with fillets. I think I may have found a fix for this particular case, even though why this happens makes no sense to me.
The strange thing is, that the semi circular sections of the curve on the left are built from 90 degree arcs (I don’t remember why I did it this way, it was done a couple of weeks ago), while the same sections of the curve on the right are built from 180 degree arcs, as you can see in this image. In each case I made one side and then mirrored.
The curve on the right is the fix I just made.
I could not figure out how to close the naked edges with Analyze>Edge Tools>Join 2 Naked Edges. Instead I had to make the curve on the right. I don’t understand why that one worked and the one on the left did not.Naked Edges.3dm (468.1 KB)
He Zews - my guess is that on the one that did not work well the arcs at the tips are not quite 100% tangent to the larger arcs.
-Pascal
How would/could I check that?
Hi Zews - CurvatureGraph and/or the GCon command (Analyse menu > Curves >Geometric continuity. The arcs should be G1 with zero degrees difference.
-Pascal
Allow me to take issue with this dialog…
This is simply making a judgement without giving the user any factual reasons why. IMO, that is wrong and the message should be changed.
First, you actually have no idea what the STL being exported will be used for. It might not even be used for RP purposes. Second, even if it is for RP, the user might be using downstream stl repair software that has better tools than Rhino to fix model afterwards. Third, as I said, if you do not tell the user exactly what is “wrong” with the model, the dialog doesn’t serve much of a purpose.
–Mitch
Pascal,
When I do CurvatureGraph on both curves I get the following image. They are clearly different.
When I do “Analyse menu > Curves >Geometric continuity” I get the following two different results.
On the left one:
Command: _GCon
Curve end difference = 3.10862e-15 millimeters
Radius of curvature difference = 0.990 millimeters
Curvature direction difference in degrees = 1.083
Tangent difference in degrees = 1.083
Curves are G0.
On the right one:
Command: _GCon
Curve end difference = 8.88178e-16 millimeters
Radius of curvature difference = 1.000 millimeters
Curvature direction difference in degrees = 0.000
Tangent difference in degrees = 0.000
Curves are G1.
Now my question is: Why would those curves on the left have bad continuity? Why did this happen? As far as I know they were created using the same methods as the ones on the right. I made some straight curves and some arcs, and then connected them. What could I have done while creating the object that made this happen? What could I have done to avoid this in the first place?
connected them how?
the curvature graph is showing there’s a kink where the two arcs are connecting (or- the radial lines of the two ends aren’t on the same vector… the centerpoint of the larger radius is too low when looking at it from the viewpoint you’re showing.)… if you upload the .3dm, someone will be able to show you exactly where it’s gone bad.
edit- oh… you already uploaded it :oops:
the purple and blue arc should share the same centerpoint and it should be at the height of the green line (assuming your goal was to make a half circle there)… one single centerpoint right in the middle…
basically, your arcs are too big -or- you’re trying to squeeze them into too small of a space.
do you see what i’m saying?
Also, it doesn’t even have a Help button to click 
Logged in MR-1204.
I get this error and as has been stated it usually links to fillets that then don’t get printed correctly when out put in Cura for my 3D printer.