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Vent hole & Hollowing


I know this has been brought up many times, but I just want to say that having to download another software tool to hollow out and place vent holes is silly. This should totally be a native feature in Preform.


No, it shouldn’t :slight_smile: Preform isn’t an editor. Being able to edit geometry would significantly increase the complexity of the software. Preform is a slicer. If you need to make changes to your geometry, that should be done in a program designed for editing geometry.

Meshmixer does a great job of hollowing and adding vent holes and it only takes a couple of steps to do it. But usually, I do this as part of generating the source model. I use Meshmixer to identify errors in the geometry, but I go back to my CAD software to correct them, I don’t do it in Meshmixer.


This argument might have been appropriate 3~5 years ago, but not today.

It took Formlabs almost 5 years to add a simple object mirroring function, when every slicer available for both FDM and SLA offered that feature since pretty much their inception. The argument that it would add to much complexity was used then too, which gave Formlabs license to drag their feet.

Hollowing and venting is another function that should be added and should be “required” on every SLA printing software. AND. nearly every major software now has the function. ChituBox, Anycubic Photon Workshop, Prusa (Slic3r SLA edition) and others.

The beauty of it is that it’s fast, and you can instantly see the difference between the solid model and the hollowed out model in terms of resin consumption and in the case of laser SLA like FormLabs the time it takes to print the model. The old way, I would either have to exit the printing software, open up the model in Meshmixer, the export it back out, open it up in Preform, if not happy with it, go back to meshmixer, and so on. Plus I would end up with a bunch of STLs cluttering up my SSD,

With ChituBox I can simply load the solid model and hollow it out as needed. it literally take 3~4 sec. and I see what my hollowed out model looks like. If I don’t like it, I hit undo, and change the parameters.

Yes, a function like this adds a little complexity, but it shouldn’t slow down the application, nor should it interfere with it. It’s just another tool in the toolbox, and one worth having.

I bought my FormLabs printer back then because it had the most elegant and easy to use software, but everybody has caught up and surpassed them since, and now they are at the tail end, and frankly it doesn’t even look like they’re eager to catch up, primarily because they are being given free passes, when we’re making excuses for them.

Wake up Formlabs !!


I agree with Dudemeister. Workflow would be much more efficient if this was supported by Preform.


I respectfully disagree here…for two main reasons:

  1. Hobbyist programs like Chitubox support this. High end professional solutions also support this (Materialise)

  2. Vent holes and hollowing are pretty core features/requirements that are required specifically for SLA. The latter (hollowing) is less important for me, but probably very important for figurines and artists. However, from an engineering perspective, vent holes are pretty common requirements. This is a very, very SLA specific thing. Because of this, I think that whatever solution Formlabs offers (in this case Preform), it should have all the capabilities and features required to set up an SLA print properly.

I’ll agree that using MeshMixer isn’t that difficult - I do use it once in a while. However, I think of it as a work around and would like to see these features native in Preform.