Okay, I'm sorry to have to make a thread about this, usually I'm quite fine with finding the answers to issues with google. But with this I'm totally stumped.

Sometimes when I undo things when working with edit poly, something strange happens. A bunch of verts delete themselves, normals get broken, verts moved...

There is never a way to undo this. I have to reload my last save. Today I loaded the object I was working on to find it like this:



which was certainly not how I left it. If I delete the most recently edit poly, the state is fine again.

I have absolutely no idea what is causing this. I've been using 3ds max for maybe 9 months now, and this is only recently started happening.

I'm using 64-bit 3ds max 2012.

I would be really appreciative of help, it's getting really annoying having my work destroyed :/

It could be several things, but two stand out for me.

A) If you change anything in the lower stacks of modifiers, it will break the rest. So for example, changing your polygons in Edit Poly 2, and then changing some stuff in Edit Poly 4 will lead to such issues.

B) It's Max, I don't know how, but in 2012, they managed to create a bug where half of the time your scene gets corrupt, not even backups will save you, and this happens randomly too, no reason to it.

I suggest getting all the Service Packs and Updates you can before anything else, and if you have the options, go either to Max 2013 or 2011 if this issue continues.

Pretty damn sure I didn't change anything lower in the stack, and undoing my last thing in the top modifier isn't going to randomly change things lower in the stack. I just installed the latest update, and I will see how it goes. If the scene is corrupt, will exporting the object save me?

thanks for the help C:

still doing it. gonna try 2013. sigh.

Just collapse your stack now and then. There's no real point in stacking like 3 edit poly's on top of each other.

This has been around in various forms since 2008 although they've fixed a lot of the really nasty issues.

As aid, its having big stacks of modifiers working on subobject selections that makes it more likely to happen. collapse the stack a bit more often and you should be able to avoid it

Ah, good to know, thanks!

wow, I load it up in 2013 to find the above item has totally delete all of its verts, and now a bunch of other things are doing the same. This is a really harsh disheartening lesson to learn

Sometimes slapping an Edit Mesh ontop of your Editable Poly, collapsing, and collapsing again to an Edit Poly can also sort out wonky mesh errors in Max..

I honestly have no idea at this point, I suggest switching on Incremental Save, so when you save each time, max creates a new save (EI: File001, File002, etc) so it causes less headaches.

Also, I know the feeling, Max corrupted a file of mine several times, deleting the UV's and corruption sections of the mesh entirely. Talk about dirty code.

I've managed to recover most of the the meshes. Generally deleting the top edit poly fixed them, and luckily that was mostly an edit poly on top of a symmetry. I've collapsed them down, fingers crossed it doesn't continue. I will put incremental save on also, sounds like a good plan. Now to remodel the piece that disappeared :/

again, thanks for the help!

Best fix, export as fbx, then re import, problem solved

If it happens again I will try that, thanks for the tip. Although I hope I can avoid it now :P

So I went to swap back to 2012 from 2013 as it seems to have stopped occurring. Now I get a can't open file error in 2012 in 2013 :/ Damnit autodesk!

When you save your scene in 2013, save as a 2012 file

oh, is there a difference now, like how office went to docx? Anyway I ended up just exporting it as an fbx and importing it in 2012.

yeah.. every f'ng year..

Yea I've had this happen to me a few times, drives me nuts. I normally the verts where in the right places but the edges and faces where all mixed up. If it wasn't too bad I would export/import to obj and it would freeze the problem and I could remove the faces and reconnect new ones.

It seemed to happen when max would crash and I would start working from an autoback file. What really helped me get around it was saving incrementally outside of the autoback feature. I bound "save incremental" to ctrl-s.