Hi Gianmarco, welcome to MoI!

There is not currently any automatic way to select only all visible objects. But I think it will not be difficult to add in a script method to enable this for the next v2 beta version, I'll look into that just a bit later.

Currently I would recommend what you are already doing with clicking to select the outside part and hiding it.

One other thing that can come in handy for this is the window select with a left-to-right window.

When you do a window select starting on the left side and moving to the right, only objects that are completely contained inside of that window will be selected. If you start on the right side and drag the window to the left instead, any objects that intersect the window in any way will be captured (the window shows with a dashed outline for this second method).

You can often use strategic placement of the "only inside" left-to-right side to capture small objects on the inside of others.

One other thing that helps with this is you can hold down Shift+Ctrl to force triggering of a window select even when starting on top of an object - this is handy when clicking and dragging on a spot would otherwise normally drag an object instead of doing a window select.

Here's an illustration:



So to do that I held down Shift + Ctrl and started the window on the left side and dragged it to the right. Only the small cubes inside of the larger sphere were then selected, the large sphere is not selected because it was not completely inside the window.

- Michael