Imported mesh inverting in zbrush

capone

Quite a noob user here so it may be something simple but I'm exporting a door from my 3D App to Zbrush and the geometry appears to be inverted. Nothing to do with normals, the actual geometry.

So instead of } am getting {

Any ideas what setting could fix this?

elte

Possibly normal issue, try to flip em and see if it works.

btw, what is your 3d App?

MoP

There are a lot of settings in ZBrush controlling import.
Look in the Preferences palette, for ImportExport, and you'll see a lot of options like "IFlipY" "ISwitchYZ" etc. See if changing them fixes it.

Also make sure you don't have negative transforms (eg scale of -1.0 in Maya or -100 in Max) on the object that you're exporting. Do Freeze Transforms or Reset XForm before exporting.

capone

Using 3dmax2009. Have imported other things fine. There are no normals on this at all it's nothing to do with that. Tried different settings with ImportExport prefs and reimported but no change. I had tried reseting xform upon exporting before so it's not that either.

Firebert

capone wrote: »

There are no normals on this at all it's nothing to do with that.

ummmmmmmmm........ :poly132:.... what?

switch culling on in max and see what happens, my guess is it will look just like the model you imported into zb.... in which case, you have reversed normals... so add a normal modifier, reverse(flip)(which happens when the modifier is added), collapse, reset xform, and export again....

do not try to fix this noise in zb... you can, but it's all up to you... if you do fix in zb, you HAVE to do it before you ever start doing any sculpting whatsoever.... make sure you have Tool>Display>double sided deselected, and select flip, then you can start sculpting.... if you have double sided on, it may look like you fixed it, but you really didn't... and if you start sculpting on the "assumed" fixed model, you will be seeing some bad stuff when you use the inflate brush for instance, and then, you'll be in such a high sub-d level that you're pretty well screwed... there's multiple ways to try to fix that scenario, but most of them end in explosions

capone

Thanks but it's not helping. Turned on backface cull and it just looks the same as it does in 3D max (correct). I added a normal mod and flipped, re exported but it appeared exactly the same.

These are my obj settings, tried changing one or two of the prefs but still no luck.

Firebert

then go back to the model before flipping, and set your export preset to zbrush in the dropdown box at the bottom, see what happens.

turn off optimization for the verts, normals, and uvs in that bottom row too.

now that i look at your image of your settings, that may have been the issue, you have normals turned off in your export...

praxedes

Happens to me all the time. Go in Zb to Tool--DisplyProperties--Flip and the geometry should right itself. It is caused by inverted normals, though, I can tell you that! I find it can get caused by extrudes and flips.

I'm guessing from your "it has no normals" that you are mixing up normals and UVs. The object might not have UVs but it has normals, because all 3d objects do- cos that's what tells the faces which way they are pointing

Try te above and see how you get on!

~P~

capone

Tried Firebert's suggestions with no luck. Praxedes suggestion worked, hopefully won't cause a problem when taking it back to max though I'm sure it's just a case of flipping again. It is indeed a flat plane with extrusions, must be problematic for zbrush.

Thanks for all the support, much appreciated.

vargatom

The flipping is somewhat random in our experience, hasn't really got anything to do with the actual normals of the object. It's as if Zbrush doesn't look at that data, but tries to guess it instead... The flip button inside the program seems to help though.

divi

it's not actually messing with your geometry, just the way zbrush displays it. so no problems when importing back into max. double will work aswell and is - at least to me - preferable on flat geometry.

MoP

capone wrote: »

Nothing to do with normals

If "Flip" in ZBrush fixes it, then it's everything to do with normals.

monkeyboy_garth

@ Mop: I think capone's confusing a normal map with normals...maybe.

MoP

It's quite funny, you'll also notice that elte's first answer is also the answer that turned out to be correct

praxedes

tis true- I just wanted to direct him to the button he needed

~P~