I've had a project going for a while, making CAS items for infants, but it bugs me that the thumbnails show up wrong (they're empty). I think it's because I have to use toddler files as a base, so the camera probably goes above the head of the infant. For clothes the camera is too far away to see the outfit properly.

Baby hairs do show in the "change appearance" menu, but since all the thumbs are empty, I have to rely on tooltips and/or clicking each hair to find the right color, and since my hair collection is only getting bigger, this is getting tedious.

I know how to make custom thumbnails for accessories (tutorial here), but from my experiments that's not possible for hairs or clothes, unless I've been doing something wrong, that is...

It's possible to fix the camera for objects (via the CRES, tutorial here), but is it possible to do so for CAS items? And if so, how do I do that?

There are resources in the Sim files named "casThumbnailCameras2_camera_thumbnail_toddler_face_fullFace_cropHShape_cres" and "casThumbnailCameras2_camera_thumbnail_toddler_face_hair_squareShape_cres" - maybe those can be used somehow?

I don't mind if it's something I have to do for all the files, as long as there's a solution I can work with.

From that second tutorial, I'd say that's how you do it. Clothing meshes and object meshes really aren't so different. If your mesh doesn't have the thumbnail_cres already in it (im guessing not), you'll have to find the default one that it is using, buried deep in the game files somewhere and then add it into your package, change it to custom, link up your clothes to the new camera_cres, and then make your edits to the camera.

I wouldn't suggest altering the previously listed cameras (but those are likely the ones you need to find), it's likely that if you change them, it will change those cameras for all items that use them - ie breaking the camera for actual toddler stuff.

I would suggest it's probably because there is no thumbnail camera for baby so the game defaults to adult camera. try changing (a copy of) one to toddler age without changing any group or instance values to see if the game creates a proper thumbnail.