You may want to send an image of your UV. But it’s good to have your coplanar faces, vertex attached or not, be aligned in your UV. This ensures that regardless of the light resolution, they’re going to receive light in the same way. Just better.
I’ve included an image that shows a quick example (only focusing on the UVs for the particular side). It’s less about the Vertex welding, and more about using the Quick UV tool inside of Unwrap UVW.
the numbers are:
- Select all coplanar faces (regardless of attached or not)
- Check the way it should face. By default (shown) it will average out the normals, on a flat face, it’s fine, but I still prefer to specify X, Y, or Z.
- Click the Quick UV layout.
- This is the result, flattening out the selection relative to the direction made in 2
I use this feature ALL OF THE TIME. Helps to create an even light distribution. I also use this when doing tiles. and other things that have small creases.
It’s still good to ensure proper welding, and won’t fix every potential issue. But in the case you don’t have things welded, this is still a VERY good way to help improve the way the light functions over an object while giving a LOT more flexibility to create an even look, regardless of Lightmap resolution.
Hope this helps!