3ds Max 2015 Normal move acting strange

Gungriffon Geona

I don't really know how to describe this so I just made a gif of the problem.

So, how do I fix this? it's only happening on the lower arm object, so maybe I accidentally flipped a setting?

E: I literally just had it stop doing it. I have no idea why.
I suppose now the question is really what CAUSES this to happen? is it a recreatable bug or just a misplaced finger on the keyboard?

Eric Chadwick

What does the modifier stack look like, and which subobject are you in? Check for constraints settings in the modifier. If you collapse the stack does it still occur?

Gungriffon Geona

Modifier stack was nothing but Opensubdiv, which I've had on everything the whole time I've been working. Removing it didn't change anything, but like I said earlier, it suddenly went away without me being sure what caused it or what stopped it in the first place.

Obscura

Seems like a constraint is enabled in edit poly - edit geometry. Set it to "none".

Gungriffon Geona

Well, that was the point. I had the normal constraint on and it was doing something really abnormal. normal isn't supposed to randomly and erratically change position at each movement like this, it's a uniform move operation.

Obscura

I'd say this is normal when you do it on a group of polygons. At least I'd expect this. I can't really tell you whats the reason behind the strong distortion, but if we imagine the normals of that mesh, and then try moving the verts along them, we would see it growing and warping similarly to what you see. Well, more like what the push modifier would do, so its still strange but not so much. 

What would you expect to happen?

Gungriffon Geona

I know it's normal behavior. I use it all the time.

The issue is entirely what would cause that type of erratic distortion from the first post.

Eric Chadwick

Reset Xform lately?