Limit the input on underground belts and splitters.

[Player 1]

The entrance and exit nodes of underground belts, are drawn as shielded from things going inside them from the sides and from above.
Splitters are also drawn as shielded from things going into them from the sides and above as well.
...but from the screenshots I'm seeing, you can rig them into accepting items from these directions.
This should be prohibited because it looks like it's breaking some sort of dimensional laws.

[ske]

Your reasoning resonates with me. It does look weird when inserters grab items out of nowhere. On the other hand changing this behavior would break backwards compatibility and many factories wouldn't work anymore and need to be redesigned. Maybe such a change would need a lot of advance notice in order to avoid a shrtstiom.

[Player 1]

On the other hand changing this behavior would break backwards compatibility and many factories wouldn't work anymore and need to be redesigned. Maybe such a change would need a lot of advance notice in order to avoid a shrtstiom.

While I don't particularly care for players who play Alpha versions of games (short of their entire saves becoming corrupted forever) since they should know what they signed up for, you could implement these rules only when players start up new games.

[Koub]

The devs have already stated it's not a bug. Thus I assume it's intended behaviour.
viewtopic.php?f=23&t=16377&view=unread#p108639

[Player 1]

The devs have already stated it's not a bug. Thus I assume it's intended behaviour.
viewtopic.php?f=23&t=16377&view=unread#p108639

Just because something is bugfree, that doesn't mean that it can't be improved. Alpha builds are generally filled with things that work in a certain primitive way until further notice.

[pib]

There are couple things like this related to belts I also feel is "cheaty". For instance, you can use inserters + underground belts to fully compress in a way that doesn't work if you use above ground belts, because the inserters can avoid collision issues that way. I don't think it's ideal at all that chaining together underground belts offers an advantage to using above ground belts outside of their ability to go underground and extend multiple tiles.

Simply making it so inserters can not place into underground belts will fix that problem, and I think that might be better than trying to remove the collision advantage some other way because the graphic for these tunnels clearly has a roof and walls on both sides. How is the inserter even working with those things in the way?

I also do not like interleaving different color belts even though it is possible. I think a yellow underground tunnel should connect to a red underground tunnel if it is oriented to do so, which would be similar to connecting a yellow belt to a red belt

[ssilk]

In my opinion this is - as already right remarked - just a graphical problem.
- Graphics of UG-belts and splitters need some kind of tuning
- Inserter movements can change a bit.

In the end this is consolidated and quite useful game-play. Just look into the wiki to get an idea about how many uses it has.