Thats a bit more than just viewport navigation ;) Selection is probably the hardest part, since you probably want "interactive" selection where you select whatever is centered in the current camera.
Normally when I select choose selection -> vertex I see vertexes in blue, when I select some of them, they are red. But sometimes I cannot see any vertexes (in blue and red). why? How could I fix it?
Set the selection mode in the 3D viewport to Face Select. In the UV editor use the UV > Show / Hide Faces > Hide Unselected command to transfer UV island selections to the mesh in the 3D viewport.
ctrl+h only works at the object level. Select the faces you want to SEE and isolate them. Viewport menu: Show -> Isolate Selected -> View Selected Click again to unhide everything.
I guess you have double checked the meshes in Maya before export by selecting one vert and activating select connected? Once the mesh is imported you can select one tool, activate auto groups, hide one group and then delete hidden. That should work.
VN feature in ADN Modeler Tools works better and I just use ADN Hard Edges selection tool, bevel it, select the flat surfaces with Angle Selection Constraint and use ADN Vertex Normal feature.
( if $selection!=undefined then ( Obj1=$selection[1] Obj2=$selection[2] Obj1.pivot = Obj1.center Obj2.pivot = Obj2.center Obj2.transform = Obj1.transform ) ) Should do what you want.
You'd use shortcuts but this way with global search input, it's more descriptive (add invert selection and convert edge selection to poly selection after dot loop + ring). Starting with evenly subdivided geometry:
You still have vertex selection model turned on in your edit poly base. Got here and turn that off and see if it helps. Some modifiers will only apply themselves to selected parts if the selection is left on.
Volume Select selects a subobject within its volume. It's there just to force that end of the model to stay selected, so the Twist above it will confine to that part, while you're adding & editing geometry in Editable Poly below it.