This is probably something, where one would say, that it would have been useful if it would have been released 10 years ago. 
3D Classic Clothing - Template
Once I wanted to ask the Avatar Team regarding this, and whether Roblox would have something like a 3D Classic Clothing Viewer. But I never really received a response, so I thought about digging into the Roblox files and creating one.
A major concern of mine is to release this, as it does aid with UV, but certain systems on Roblox do not, and I don’t know if they’d keep up with it, eventually if they don’t they can make use of this as well.
What is this?
This is a 3D Model Template, that you can use to do 3D Painting to create Old Legacy Classic Clothing!
Especially in Substance Painter. While it does have a few flaws, regarding Projecting images onto corners (probably because how the Roblox UV works?) it doesn’t act perfect. However, it is using accurate data from the original Roblox UVs.
What’s special about this?
Since this is a 3D Template, that you can use in 3D Software, like Substance Painter. You’re able to stretch things and create indiviual patterns for individual Character Body Meshes that otherwise would look “distorted”.
As example, notice how the Character on the right, has the same shirt, but the texture is stretched.
By using the 3D Model, you can counter-measure this by stretching your texture directly in 3D space. This could be also for Textures that you’re trying to project things onto.
Learn about Composition Meshes
Unlike how regular UV and Textures work. Shirt and Pants work different in Roblox. As you may know, there’s MORE than just one Character Mesh on Roblox. Infact in the future there is going to be infinite amount of Character Meshes.
All these have a unified UV, and Shirt and Pants work on most Models thanks to Composition Meshes.
I am unfamiliar what the math behind it is. But Composition Meshes are utilizied as references to compose your Character’s Texture out of the Classic Shirt and Classic Pants!
What’s important is that the Composition Meshes contain the Original UV Data.
How I created the UV
These Composition Meshes are found in our Roblox folder. They’re .mesh files and have their own format. This seemed a problem at the beginning, however I took them and put them in Roblox Studio and then exported them as an .obj with the Template Texture. And this revealed the UV.
With careful XYZ cleaning up and re-modelling a sketch of the R6 Model to place the UV onto, I managed to create the template!
Example way to use
You get the .obj file.
You create a texture with it.
And then you export the texture! For instance you can export the 2D View to have a baked down version of all layers. The downside is that you’ll eventually end with a black image if you baked textures, or that you have to tweak the areas on your texture that appear too bright, because of the way lighting in Substance works.
Import into Roblox
You can use Plugins to have temporary assets that you can use to preview how things look like. All you have to do is to create a Shirt or Pants Instance and insert the Temporary Asset ID.
See this Plugin for instance: https://create.roblox.com/store/asset/3469049880/Local-File-Importer-Plugin
And the result will become this:
Additional Images
Modifiable Model
There’s two versions of the .obj Model. One has normal arms the other one has the arms moved a little bit more up. This was because I wanted to experiment with Substance Painter for accuracy.
I made it so that individual parts can be toggled on and off. While there’s are way many more things I could try that’s what it is for now.
See this image for comparison. I made a cross, and the point is that the transition happens nicely. It was a bit difficult to see, hence why I created a version that has the arms more moved up, to see if it would make a difference in Substance Painter or the 3D Editor in Photoshop.
Resources
- classic_clothing_rig_template.obj (74.4 KB)
- classic_clothing_rig_template_shifted_up.obj (74.4 KB)
Texture Templates are found here: Classic Clothing | Documentation - Roblox Creator Hub