Poll: is "Swap UVs" mesh import setting useful for anyone?

I'm probably not the best person to answer, as I'm not a 3d modeler, but I've never had to use it at all. All of my 3d models that I've imported have always come in with UVs. The greater problem was when there weren't any UV coordinates, and when I told Unity to create them, the output would not be accurate. But that doesn't really happen much now anyways, so I'm really not concerned one way or another.

 

I haven't ever used it and you can always write a postprocessor that swaps it like you are saying.We already use a postprocesor for many things anyway. To be honest I'm sure most people would rather prefer to have support for more UVs per mesh. I know I would !

My opinion is that as long as there is another way to achieve this then I don't see why it really needs to stay if its getting in the way of something that would be of great use to everyone.

 

Having multiple UV sets would be a godsend.

 

If you added support for multiple uv sets, this would cease to be a useful. Right now however, sometimes when you lightmap, unity will swap the uv's, and you need to check this to swap them back. Similarly this can happen on import if you have multiple sets of uv's, and unity doesn't pick the one I think it should by default

Having multiple uv sets as a default would be great, especially and perhaps purely for decaling! I know someone who is working on a fighting game, and using a uv layer for damage would be ideal as well.

 

Hey there Aras, always nice to see staff from the Unity development team around here

I personally have never used Swap UVs myself, so I really cannot comment about its utility.
As far as multiple UV channels go, I am all for it. That is something that would be very useful for me.

So, +1 for multiple UVs here

 

It can be super handy with one of the older... I want to say Blender exporters? I remember it had some pretty severe FBX problems.

 

I see. By older exporters, do you mean Blender 2.49 and previous?
I mostly use Blender 2.62 and higher these days

 

I honestly couldn't say since it's only affected me once before, using somebody else's model. I switched to Maya 2012 a while ago and it's been smooth sailing ever since.

 

If you add support for multiple UV sets, would it be a good idea to allow UV set selection whenever there is more than one present? Sounds ideal for lightmaps, etc. even in the current situation.

 

If I thought at the time this was a bug, I'd have kept some examples around, I guess next time this comes up I'll file a report. Its not exactly uncommon tho, last time I was working with my environment stuff in unity I had a few instances of this. I'll keep it in mind when I ramp up in that area again.

 

I have used this option on a small number of FBX models that have come out of 3DS Max 10. I don't recall the exact number, but somewhere around 4 or 5 models out of appx 250 models. I voted I "absolutely need it!!!", though I don't feel that strongly. It would be a pain in the backside to figure out which ones needed it, and then put in special cases, though.

 

I've definitely used it in the past with Softimage objects. I'd prefer you not remove this capability.

 

I frankly haven't checked in a while. Since Unity doesn't support Softimage directly, the problem would have been related to FBX. Supporting multiple UV sets would be great, just please don't ask us non-coders to have to come up with more scripts.

 

So, this is a crazy idea, but what about removing direct support, making a simple script for this and putting it as an optional thing on the Asset Store?

Or this, yeah.

 

I wonder if whatever the 'Swap UVs' option does can be extricated in the form of an independent script and put in the community wiki so that those people who still need it will always find it there

If Swap UVs is the only stumbling block to multiple UVs, then the above solution would be a win win for all of us.

Also, the other way around would be just fine for me. If there was any way to leave Swap UVs as it is and a way to import multiple UV channels in an independent script, that would be welcome as well.

I remember trying to find material about getting multiple UVs in unity, and during that trial I failed to find a script for that. There was some talk of using some kind of shader magic to get that but that is beyond my capacity

 

I've just voted to keep - but not sure if it's because of bad geometry or a bug in choosing UV layering.
But the only way I could get my blend to work was by swapping the UVs. I didn't purposefully add a light map. See zip file here, blend file and textures by nobiax. I let unity load the blend file and import materials, then hook up the textures in a textures folder.

Note - I've got two UV Maps in blender, one for the rock face and one for the snow top.

Notice that without UV swap ticked, the rock face is super shiny.

I also don't hook up specular because it adds lots of noise - not sure if they are incompatible specular/height maps, would be good to have a slider for correcting these.

(Fixed the following - this was smoothed edges with 90 degree adjacent face - making tiling of this asset look bad).There's another weird issue where the right edge is dark as if it's merging two textures together, yet the materials appear correctly configured in blender! Also I'm sure it's not respected the positioning of my UV maps.

 

I've just tested a basic cube that had two separate uv maps defined in blender, and this experiences the same problem.
The only way to import it is to tick the swap UV button, or just use one 'named UV map' area in blender.

So, I can re-use the same 'named UV map area' to define the points, and just swap different images in the node-editor. But it's not neat to do that in blender in a complex model.I like the separation of concerns of having separate named UV Maps, but is that bad practice? I'm a noob.

 

@Aras
Please Please Please Please do not remove this. It was the only way for me to fix some weird Blender UV bug, inside Unity!!!

Was banging my head against the wall because the UV was fine inside Blender, but screwed up In Unity. This was the fix for my FBX file.

 

Aras hasn't replied to this thread in five years.

 

Well hopefully he reads the mention.

 

I'm pretty sure that, considering nothing on this front has changed since 2013 at the latest that you have nothing to worry about.

 

@Aras
I say first and foremost we need a UV preview tab in the import preview.
There is no way to preview UVs in Unity except after light baking.

 

Yep that all goes in the feedback section of the site.