Export STL without Square Holes

[Wes_Tomer]

Hello,

To prevent display lag in AR on the HoloLens, I often need reduce the number of polygons (facets) of a particular model. When I load the final PVZ into Vuforia Studio I always run the CAD optimizer, but sometimes this still results in too many polygons. So before exporting as a PVZ from Creo Parametric, I replace especially complex parts (lots of curves) with STL copies. When I export a part as an STL I can adjust the parameters to create a very fine detailed mesh of polygons, or a very low quality where all of the round geometry is represented by squares. I would like to preserve the geometry of round items so that they have at least 6 or more sides (not 4) -- however I want to simplify the rest of the part much more dramatically. Is there a trick to get the best of both worlds?

One time consuming method to do this is to extrude a polygon (6 or more sides) in the place of every circle (whether adding or subtracting material) -- this prevents exporting to STL from over-simplifying a circle into a square -- but it allows me to highly optimize all of the other geometry. Is there a better way to do this? I can't afford to use my time consuming method on parts that have lots of holes with countersinks and circular features. Please see attached - polygon-reduction.jpg

[Wes_Tomer · Accepted solution]

I solved my problem:

Here's the hack:

1. Open the Gear_Case.prt in Creo Parametric & export as a PVZ
2. Import the PVZ into Vuforia Studio and run CAD optimizer
3. Navigate to the Gear_Case_High.pvz in your folder browser
   1. C:\Users\****\Documents\VuforiaStudio\Projects\****\src\phone\resources\Uploaded
4. Copy this file, and open it in Creo Parametric as a new part. Save the part.
5. Insert the part into your Creo Parametric assembly (to replace the more complex one).
6. You won't have much to constrain to -- so just use simplified reps to exclude the complex gear-case.
7. Export the assembly as a PVZ
8. Import into Vuforia Studio and run CAD optimizer
9. You will be able to use the ****_Low.pvz file to reduce polygon count WHILE still retaining a nice level of detail for all round parts for the gear_case

How's that? 🙂

Did anyone understand all that? I hope it's helpful to someone. What I'm doing is making selective use of the Vuforia Studio CAD optimizer. It would be nice if this sort of thing were built-in, but it's a good hack.

p.s.

For everyone who came to this topic so they could export a STL without square holes, (and doesn't care about all the rest) just open the part in Creo, then Save As -> Save a Copy -> Stereolithography (STL) file type + check the box to customize export. Click Apply to see what it will look like. You can change the parameters, and hit Apply again until you like what you see.