Hi, when in the lowest subdivision level of an object, the mask lasso tool masks hidden parts.
To reproduce:
- In the default scene scrub the multiresolution slider to the left.
- Assign a different Face Group to the half of the sphere.
- Hide one of the halfs.
- Choose SelMask and drag a lasso around the sphere.
- Clear Hide.
→ Now the whole sphere is masked.
When choosing any other subdivision level the masking only affects the non-hidden parts of the mesh.
The trim tool in boolean mode trims hidden parts of the object as well (on all subdivision levels)
In Legacy and None mode it works as I would expect though