Maya Duplicate Special/uv reversed

KWAN

Hey Polycounters,

I have a model that I'm trying to duplicate in Maya. I use the duplicate "special" option

The problem is that the UV's get reversed.

I tried to flip them but they don't line up then. Any suggestions?

Thanks

KWAN

gray

it does not do that under normal circumstances. you can try 2 things.

1) open the options for duplicate special and reset settings. then try to duplicate.

2) clear the history on your object as much as you can then try to duplicate.

KWAN

To clarify I'm doing a x: -1 under the duplicate special option box. It flips the geo along with a -1 on the uvmap.

I usually reversed the normals to make them blue but the texture still shows it being reversed.

KWAN

here are the settings:

gray

use the transfer attributes tool.

*uv's only *component mode *mirror off *flip uv's off *closest point.

have no idea what your up to but that will copy the same uv set from on obj to another. even if its flipped with reverse normals.

KWAN

Those default settings don't work I tried it a hundred times. The green lines are the normals.

gray

what is is this screen shot showing?

can you give some more detail about what your doing and precisely what the problem is with the uvs.

i know you want to duplicate an object. and you flipped in -x. and the duplicate uvs are shaded red no blue like the original. you want to match the uvs on both sides? not sure i get it.

KWAN

Just to show the texture being reversed even though the normals are sticking in the right direction.

I always thought red uv's cause issues and to always have blue. I always did a reverse/flip technique for uv maps.

Shanthosa

KWAN, when you scale something by -1 along an axis you are turning it inside-out. The texture applied to it will be mirrored according to what was there when you duplicated it. This is fine in a lot of cases, especially if it is a symmetrical object. Obviously if you are putting letters or something angle-specific on the texture, then they will get flipped along with it.

Having mirrored UV's like this can allow you to save 1/2 your texture space too. The normal's direction has no bearing on what the UV's are doing. When they show up red like that when you are shading them in the UV texture editor, it just means that that shell is reversed. Ideally the original and the duplicate's UV's will line up perfectly so that the texture mirrors seamlessly over the border.

kaicho

I wish this post had solved my problem, but it aint :S, when i use duplicate special i get my normals flipped, also haven't found solution to this, because people seems to not have this problem around.

Harbinger

What exactly is the problem? You're inverting it's scale, the normals will be flipped. Just reverse them manually after the duplicate. If you see your shaded UV's turn red in the UV editor, it's not necessarily a problem. It just means that those UV's are projected from the opposite side of the normal direction.

kaicho

being an instance, i cant select those faces, both sides are selected as one, so both flip and always one of them gets on the wrong way, anyway, most tutorials i've seen around do this without normals problem at all :S.

Such an easy task on 3dMax got me stuck in maya :poly142:

Harbinger

The Duplicate Special instance with negative scale trick is usually used because Maya's old tools for mirror modeling were crappy or non-existent. If you are finished modeling and want to simply mirror the other half of your model, use the Mirror Geometry tool, then you should have no issues with your normals.

kaicho

thanks, that's a good way around, but i was looking for something similar to the symmetry tool, just to model in one side and at have instantly the whole volume of the model, quite useful when i'm modeling chars without a reference, is there another tool i can use for this?

Harbinger

Maya 2015 added some much improved symmetry tools with Modeling Toolkit. If you don't have 2015, the only thing I can suggest is to model with the inverted instance approach and then once your done, mirror the mesh with Mirror Geometry or simply delete history on the instance, flip the normals, and then merge with the other half.

kaicho

Thanks for all the advice, i'll try 2015 and dig a bit deeper to see what i find

Klaudio2U

You can try instead of negative scaling, rotate 180 on Y. Just be sure to center pivot first then then move pivot on one axis to where middle of the mesh is.

[Gordon] Game Designer

Did you do a negative scale?
It should be ok after freezing your transforms
Then the black backside in general, happens because of a new default setting in the viewports:

Viewportmenu -> Lighting -> Two Sided Lighting is unchecked!

Solution:
Enable it and it will look the same from both sides again.