PreForm repair with NetFabb not as good as NetFabb?

I created a model today that PreForm said had issues that needed repair. My understanding is that PreForm uses software licensed from NetFabb to do these repairs. On my model today, PreForm said that the repair had failed and the model would not import.

I took the model to the freeware version of NetFabb (I’ve been using the same version for probably the last 2 years now, so it’s a pretty old version). I figured it wouldn’t do any better at repairing the model, but at least I’d be able to see where the model was busted so I could go back to my CAD software to fix it manually. On import, NetFabb said the model needed repair, no surprise. I went in to the “First Aid” function on NetFabb to see what NetFabb didn’t like, and saw the problem was only a couple of “holes” caused by 2-vertex polys. I used the “close trivial holes” function and the part was repaired, 1 shell, no holes. After this it imported in to PreForm just fine (and printed just fine, too).

I could have just as easily used the NetFabb autorepair function without even bothering to look at what was wrong with the model, and I’d assumed the repair feature in PreForm did the equivalent of a NetFabb autorepair. But based on this experience, it doesn’t seem as if that’s so.

Is there any information available on the capabilities of PreForm’s NetFabb repair compared to the freeware version of NetFabb?


I have NetFabb Pro but not the slightest idea how to use it, especially to the level they demonstrated on their webinar, which I have watched 3 times now without sound. Netfabb’s on line how to videos are awful or non-existent.

I occasionally get a warning from PreForm and click OK repair. Most of my prints have been coming out well. It just really sucks to have a $1800.00 investment in a program and not use it.


NetFabb will tell you where a model is busted even if the freeware version won’t repair it. I found that for the most part, it’s simple non-manifold edges and 2 point polys that screw me up, artifacts of imperfect CSG, and the freeware NetFabb fixes them all just fine using “automatic” repair. I was never forced in to a situation where I needed to pay their outrageous software license fee, and have been getting on with the freeware version just fine. I have had the occasional too-screwed-up-for-manual-repair problem, and have fallen back on MeshMixer and MeshLab with some added success. All freeware tools. If you get a lot of geometry errors with your existing CAD software, the right answer might be to upgrade that to something better rather than focus on tools to repair your models coming from your current CAD software.

But. If PreForm implemented at least the equivalent of NetFabb’s freeware version of autorepair, in my case at least I wouldn’t need NetFabb anymore…freeware or not!

NetFabb able or correct or normalize faces? I noticed sometimes if a model has a flipped normal it will act like a hole and cause errors. Though I never had a model I couldn’t load into PreForm I am curious.

In a pinch I have been using Ultimate Unwrap 3d or Amapi Pro to correct any model artifacts in advance of importing into PreForm.

Yes, it understands the concept of “inside” and “outside” since it’s trying to make the model water-tight. So assuming NetFabb succeeds in closing holes, it can also correctly flip polys so their normals point outward. There is a repair option for flipped polys.

MeshMixer is another decent free-ware program that’s fairly good at fixing printable geometry…

I have NetFabb Pro and its great other than a few spelling problems in English by its German creators.

I do all my repairs in Netfabb Pro. I used to use the cloud version and personal version but since I am using for paying customers I bought the commercial license and it has been worth it.

On most projects, all I have to do is:
Click a part to highlight it in green.
Click the Red Cross to open the repair window.
Choose Automatic Repair.
I then usually choose Extended repair which shrink wraps the part to make it into as few shells as possible, normally one shell.

I also often use the extrusion tool and triangle reduction for files that have a finer mesh than they need

I use a lot of the other features beside the repair in my workflow such as manually adding supports, geometry, or text.


If you are in the US I would like to make contact with you. As you may have read I have NF Pro and need some help learning it.

Please contact me directly with your phone number and a good time to call. Weekends are probably best.