Notifications
Clear all

Inverse Negative Volume  

  RSS
Jeremy Grieshop
(@jeremy-grieshop)
New Member
Inverse Negative Volume

I'm very, very new to all of this, so fair warning!

I feel like this should be a simple thing to do, but perhaps I'm thinking of it all wrong.

I messed up a print earlier and would like to finish a small section of it and attempt to glue the pieces together. The section I'd like to reprint is a small area that can easily be described by taking a cylindrical cross-section and effectively "cutting" the rest, keeping what's inside the cylinder.  

In PrusaSlicer, I can easily create holes by adding Negative Volume Shapes, but ideally, I'd like to "invert the mask" so to speak and keep the "hole" while cutting the rest of the object.

A good example of this would be if I had a cylinder and instead of making a "donut", I'd like to make a "donut hole", discarding the "donut".

Posted : 28/09/2022 9:57 pm
fuchsr
(@fuchsr)
Famed Member
RE: Inverse Negative Volume

Possible but not totally trivial. You can use your model itself as a negative space and cut out from a larger object. So in your example of a donut hole, you have to use a part that is slightly larger than the donut hole, then load a donut as a negative volume and overlay it, which will leave the donut hole. 

Posted : 28/09/2022 11:36 pm
Jeremy Grieshop
(@jeremy-grieshop)
New Member
Topic starter answered:
RE: Inverse Negative Volume

Aha, thank you!  I was actually on the path to doing just that, but I couldn't figure out how to save my modified model out to an STL, so I could select it as a negative volume in the menu.  Whenever I save out my model to be re-used later, it doesn't save the sliced version, "merged" - instead it saves out the two separate objects I used to create the slice. 

I know, I have much to learn, lol!

Posted : 29/09/2022 12:44 am
Share: