Roblox Studio Unions Dark Surface Shade Bug?

[AgentNumbNuts]

Hello fellow roblox developers attention please, just today I was in studio trying to unions these parts
but after I unions them, some of the surfaces have a darker shade over the part, I’m currently searching to see what causes it, because it was not happening before in May.

I have also notice that the textures for plastic on the same spot that is slightly darker does not show up,
Could this be a bug in studio?
am I doing something wrong?

Here is what I’m talking about video below
robloxapp-20230704-2329550.wmv (6.2 MB)

• Are You Having The Same Problem?

[grimmerschool2 (PartyNoob)]

This is a glitch/bug with a recent update.
Try setting the SmoothingAngle to 1, that will fix errors on most unions.

[Scottifly]

Try the Search button up top. There are other posts about this as well.

Union shading reversing and glitching

[image] [image] [image]

This one is from 2021, but has been resurrected because of this same issue:

Unioning changes the part colours of some faces? MAJOR BUG WITH CSG

A few things have changed since this post was made: CSG V3 is now fully released, and is not a beta feature. Enabling legacy CSG does not enable CSG V2, it actually enables CSG V1. Separating old CSG V2 unions retroactively applies the negative part colours to the union even for steps before the current union separation, which makes improving old models extremely tedious. CSG V3 negative parts also darken the faces they have touched, for no reason at all Roblox staff have ignored…

[AgentNumbNuts]

thank God they are people like you around
it worked!

[DoubtfullySkeptical]

I was so worried that CSG broke down just when I needed it. Thank you!

[BritishTrainspotting (BritishTrainspotter)]

Originally CSG V3 didn’t have this problem at all. Its absurd that they broke it and managed to let that broken update get pushed out without even testing it.

While smoothing angle may fix the majority of a union, parts of it may be irreperable, even after re-rendering it multiple times:

[Frewsty]

Is there anything else I can do to remedy this issue? I raised the SmoothingAngle and small fragments of unwanted color still remain.