UV mapping a character model to SLUV

[Ren Ichibara]

Greetings,

I made a character model and I'm wondering how to uv map it to match SLUV.

I'm currently using blender for my uv mapping but although the seams are as close as possible to the second life system avatar model, the uv islands coming from blender unwrapper are nowhere close to SLUV.

Should I switch to another software for the uvmapping? Is there a better process that I do not know of people employ to get SLUV on their models?

[Ren Ichibara]

Hello,

After many failed attempts I finally discovered a way to make the SLUV happen on my model in blender.

You need a quad version of the default system avatar rigged with a skeleton.  (Avastar come with one by default but you can also get one from the SL wiki)

Your model don't have to be rigged but it will make the rest easier.

1. Scale your character model to match as closely as possible the system avatar.

2. Pose if your rigged character or the system avatar so that both models match each other as closely as possible.

3. Separate your character model in pieces that match the system avatar (once again to make your life easier further down the line) Ie: hands, feet, torso, legs, head (if present)

try to make the cuts near where the system avatar seams are.

4. Pick a body part on your character model that you want to SLUV map and grab the corresponding part on the system avatar.

Use a shrinkwrap modifier on the system avatar body part so that it overlaps your character model body part as closely as possible.

Caveats: Using a surbsurf modifier on the system body part first will make it easier for blender to wrap it on your character if it's topology differ a lot from the system avatar. If you use the subsurf, make sure you don't enable modify UVs.

5. Select the system avatar body part and then shift select your character body part. (The system avatar body part should be highlighted in orange) Press CTRL+SHIFT+T and then select under: face corner data -> UVs.

Your avatar body part should now have SLUVs applied to it. Repeat for all the other body parts. The better of a job you do with the shrinkwrap modifier or any other method to match both objects topology the better the unwrap will be.

 

Sarah Beil.

Edited January 10, 2019 by SarahBeil

[Kyrah Abattoir]

The subsurf will smooth/deform the original tho so you won't be as accurate.

[Ren Ichibara]

2 hours ago, Kyrah Abattoir said:

The subsurf will smooth/deform the original tho so you won't be as accurate.

Yes that's why I said you got to toggle off the option to subdivide the UVs in the modifier's option.

In my experience I find the results to be much better with subsurf as it gives the default system avatar enough polygons to stick to my model much more accurately.

 

[Kyrah Abattoir]

I wasn't talking about the UVs.

[Sean Heavy]

On 1/9/2019 at 6:20 PM, Kyrah Abattoir said:

The subsurf will smooth/deform the original tho so you won't be as accurate.

 

On 1/9/2019 at 11:24 PM, Kyrah Abattoir said:

I wasn't talking about the UVs.

What won't be as accurate if you don't mean the UV? Isn't the original post only about copying the SL UVs?
 

[Kyrah Abattoir]

The LL avatar being the reference geometry whose UVs you are trying to match, smoothing it will essentially make your reference 'drift' from its original configuration. Yes it's smoother but its geometry is now an incorrect reference point.

[Sean Heavy]

3 minutes ago, Kyrah Abattoir said:

The LL avatar being the reference geometry whose UVs you are trying to match, smoothing it will essentially make your reference 'drift' from its original configuration. Yes it's smoother but its geometry is now an incorrect reference point.

So, are saying that the UVs that are being copied from the 'subsurf'ed LL avatar will not be accurate as the UVs on the original LL avatar?

[Kyrah Abattoir]

When you texture match two objects the UVs are only one half of the equation.

You want the UVs to match but you also want the geometry itself to be reasonably close so texture details will end up roughly in the same area, with the same distorsions. Smoothing your reference will have a "relaxing" effect on the mesh and move your reference points.

Edited January 15, 2019 by Kyrah Abattoir

[Sean Heavy]

Thanks @Kyrah Abattoir, That makes sense.

So, while this procedure, suggested by @SarahBeil, won't create a perfect duplicate of UV mapping compared to an original LL avatar UV map, it would at least be a good start, (compared to blenders almost random UV assignment), to be tested and adjusted until one is happy with the way a texture shows up on the new mesh.

[Kyrah Abattoir]

Yeah I didn't precise it, this is WITHOUT "subdivide UVs" ticked.

But yeah my point was: Do whatever you want with your custom body, but keep your reference untouched while you try to do your UV and geometry matching.