I have been on the hunt for what is causing this issue and have emptied my mods folder trying to find out what is causing it with no success. I've also emptied every other folder possible (dcbackup, dccache, library, savedsims, overrides, etc.) Using CC clothes in my filming game folder causes neck distortion and/or waist distortion (females too). This is a separate game folder that I use to film in to keep it light. (Update: To clarify, putting anything EA on the sim fixes the distortion.)

In my main game folder that is stuffed full of cc, everything looks normal. So I'm thinking that instead of being something wrong in the filming folder, something I have in the main game folder is fixing this issue. Does anyone have any idea what that might be? I'm attaching pictures of the issue. And also pictures showing how it should look and does look in the main folder.

Filming:


Main:


I've tried everything imaginable to test this and it always messes up necks in the film folder, and does not mess up necks in the main folder. I've used base game sims, slider sims, no cc sims, the minute I put a cc shirt on any sim in the film folder it distorts. I could just stop using CC in my filming folder but geez, that's drastic!

A little more info: I go into my main folder, make a sim, export, rip the S3P into a package, put the package in the mods file of the film folder and get the sim with all cc from the sim bin. Doing this exact same process using the same sim file in the main folder doesn't have this effect.

I would guess it's likely a slider issue of some sort, maybe even mismatched MC CAS settings between the folders.
If the main example is from an existing save and the filming example is from entering CAS immediately in a new save it's likely the latter, from not being in MC CAS with a sim that was made with it.

The easiest solution would probably be to ditch the current filming folder and make a new copy of your main folder and narrow down its contents from there.
Then when you open a save in the filming folder, select a household and let the game run long enough for NRaas to initialize. Make sure the MasterController > CAS settings are correct, then enter MC CAS to make your changes to the sim(s).

CardinalSims, I’m getting them from the sim bin in CAS, not from a save. Using the same package file in both folders creates the differing results. I think my MC CAS settings are the same but that’s a good thing to check. If they are the same I’m going to try your other idea of a whole new game folder for filming. Thanks for the suggestions.

Well I finally figured it out. I started over with a fresh folder and started transferring. It’s something to do with the shirts not working when included in the sims3pack. When I put the actual cc shirt package files into the mods folder it fixes the problem!

Thanks, CardinalSims, for the new folder suggestion cause I was fixing to go on a massive hunt through 50 gb of mods!

I'm going to leave this question here in case someone else at some point tries to find out why the neck seam is borked in their sims 3 cc shirt.