Symmetry without screwing up UV's

[Geta-Ve]

So, I had never realized that this was an issue until I ran in to it a couple of weeks ago.

Basically, you can not use any kind of symmetry if you have already created your UV maps. Unless I have missed some obvious, or not so obvious option somewhere?

The reason being is that once you have your UV maps set up and you delete half the model to mirror, you also delete half the UV's.

This has become a big issue for me lately. I would love if Wings had a more standard way of implementing its virtual mirror functionality. IE. some way where you didn't have to remove the half of the model you wanted mirrored. Simply selecting your middle loop would be a nice alternative. Or even maintaining the UV's behind the scenes whilst you go about your mirroring.

[Wegg]

I have ran into this a lot. It is usually at this point that I have to stay in Lightwave's modeler. I'd much prefer to stay in wings, obviously but symmetry and embedded morphs force me to step out of Winged Edge land. :-(

[ggaliens]

Post me a cool model with 1/2 UVs missing.

I might just try to whip up a plugin to mirror.

... if you want.

[Wegg]

The way it works in Lightwave is that you select an axis to mirror. . . and if the modeler finds a corresponding point/edge/face on the mirror side, then it will manipulate that side in the exact same way. The behavior is exactly the same as Wings' Virtual mirror but without having to slice the object in half (blowing away half the faces). Having intact UV's because of this behavior is really just a bi-product of that workflow. I can make a video for you if you'd like.

[Wegg]

Not to beat a head horse here but I would love to point you programmer types to an implementation of symmetry that looks really awesome. Far better than Lightwave's and, obviously a zillion time's better than Wings' UV destructive method.

http://www.twistednormal.com/

On their front page towards the bottom is a feature video. In that video at about the two minute mark you can see the symmetry mode being enabled. Pretty standard. But THEN. . . he enables "Topoligical Symetry" Mind blown. . .

[ggaliens]

I could program UV topological symmetry w/o too much trouble I think. I would not do it as interactive ... more like "Update UVs based on topological symmetry". Mirroring geometry gets a bit weirder because what happens when one "turtle flipper" is smaller than the other in some kind of non-linear way ... how does a programmer do topo symmetry for geometry in that case ?

[Wegg]

If one point on one side moves along it's normal by 1 world unit, move the other point along it's normal one world unit. If one flipper has been scaled differently then it will not work right and the artist will need to correct for that. Most of the time a-symmetrical features. . . like on a face or animal are minor tweaks. Where I think things would get hairy is when the artist decides to model in a mole on one side but not the other. At that point the point count and topology has changed. . .

[boredom]

So, I had never realized that this was an issue until I ran in to it a couple of weeks ago.

Basically, you can not use any kind of symmetry if you have already created your UV maps. Unless I have missed some obvious, or not so obvious option somewhere?

The reason being is that once you have your UV maps set up and you delete half the model to mirror, you also delete half the UV's.

This has become a big issue for me lately. I would love if Wings had a more standard way of implementing its virtual mirror functionality. IE. some way where you didn't have to remove the half of the model you wanted mirrored. Simply selecting your middle loop would be a nice alternative. Or even maintaining the UV's behind the scenes whilst you go about your mirroring.

Forgive me if I'm not understanding your problem correctly... Can't you UV map half the model (lose half the coordinates when you dissolve the mirror), duplicate it, flip and weld?

Sort of like manually mirroring the model, using duplication to generate the second half with UVs.

[Wegg]

Every time you want to make a change to your mesh that is symmetrical!?! Yikes.

[Geta-Ve]

Forgive me if I'm not understanding your problem correctly... Can't you UV map half the model (lose half the coordinates when you dissolve the mirror), duplicate it, flip and weld?

Sort of like manually mirroring the model, using duplication to generate the second half with UVs.

You definitely CAN do that, but lets say that you have to make slight revisions next week, and then a week later you notice a couple of polygons that could be reduced, and then a couple of days after that the animator comes back and tells you to add a couple of loops for better deformations.

etc. etc. etc.

I think that this Symmetry issue is less about the UV's and more about how symmetry is handled in Wings. Personally I'd prefer not to have to split my model in half every time I want to model symmetrically, this gets to be a pain when modelling with multi object structures, like ships, vehicles and buildings.

I would love an option that mirrors straight down origin. Any object, operation or function that takes place on one side is duplicated on the other.