Strange Smoothing/Normal Errors

Xelan101

I've been working in Max 2011 and for some reason at random when I remove a face or attach pieces of editable poly together (I think there may be other triggers but those ones stand out in my mind) I'll get really weird smoothing/normal errors sometimes entire faces black out or sometimes only portions of them do.

The only way my roommate and I can find that fixes the problem is to remove the face entirely and then cap it off, this is fine when it happens to one or two faces but when it happens to half the object it becomes quite a hassle as you can imagine.

Now I'm definitely not a novice when it come to 3DS Max but I'm by no means an expert yet. I'm wondering if other people have had this issue with 2011 and more importantly if they have any tips for preventing and or fixing this issue that I may have overlooked (which is very very possible) that could fix the issue.

Treacharous

If the face goes black than that could be a normals issue, you can try putting a normals modifier on it and flip faces.

Xelan101

Thanks for the tip. Unfortunately I tried it out and the black faces were unaffected by the flip >.<

Ghostscape

post screenshots.

Xelan101

Here's what the issue looks like. Sorry I didn't think to post it outright.

The entire model just has the basic grey material.

Ghostscape

flipping those polys with the editable poly's flip command does not change them at all?

In general your normals are pretty nasty on some of those super high-angle 'curved' pieces, but the pure black bits look completely fucked.

First, drop a reset x-form on it (utilities panel, looks like a hammer, reset x-form, apply reset x-form, then collapse your stack down). fyi this wipes your undo history.

If things change once you do that (not necessarily better) that's good, that means we're on the right track. Next, detach any individual black elements and try flipping their normals with a normals modifier or by using the flip command on selected elements in the editable poly modifier panel.

If that doesn't get you where you need to be, the next thing to do is select all of your verts, do a very small threshold weld-selected to get rid of any shitty broken verts, then apply auto-smoothing with a very low angle. This should make your mesh look all faceted but it should also fix any last errors you have.

Anything left that is still fucked you're going to need to nuke and rebuild those faces, when you went through and tried building faces while your x-forms and normals were all jacked you probably made it worse.

All of this is somewhat destructive and your mileage may vary, etc etc.

Xelan101

Thanks I'll try that out as soon as I get the chance. Hopefully it'll get everything fixed.

Also any clue what effect a normal map would have on this error? One of my friends thinks it should override these issues but I'd rather figure that out now rather than when I need it done.

Ghostscape

a tangent-space normal map will not work. An object space normal map might improve the areas that aren't completely flipped, but this isn't something you solve by slapping a normal map on it.

Xelan101

The reset x-form and detaching seems to have worked everything looks like it's settled back into place. thanks for the help, I knew about rest x-form, just not how important it was.... well that's a lesson learned I suppose.

Oh and the normal map in question is a high poly bake by the way.

Thanks for the help.

Will Faucher

Another method that works for me is applying 2 Normal modifiers and collapsing them afterwards. Glad you got your problem solved though!

Eric Chadwick

Just be sure to re-bake your normal maps after doing this, if you've already baked them... the vertex normals have a strong effect on the normal map.