often you have to hide parts of a mesh in edit mode, so you can more easily make selection or limit an operation to only part of the mesh.
This is great, but the problem is you generally need to be able to see the hidden portion so that relative proportions can be met.
In this instance you need to unhide the hidden verts/faces/edges whilst keeping the sub object selection you’ve made.
Unfortunately, unhiding parts of the model also results in those unhidden elements being selected, which puts you right back at square one.
SOLUTION
- don’t select elements after unhiding them.
- have an option to ghost hidden elements so that you don’t even need to unhide. This would be ideal because it would mean you could see what you were doing without operatins affecting the hidden/ghosted parts of the mesh.