How about adding "tree textures" to Orbiter?
Beacon lights are a light texture that always face perpendicular to user viewport.
How about making a generic and customizable surface base object that could do the same.
If you add a tree texture with alpha channel you could be able to make a tree.
It also could allow people to add ground crew and other objects that could be represented that way.
How about house texturing?
In Orbiter there are standard objects that look like a house or a hangar.
But the problem is that you have texture appearing in a very weird way.
So if you intend to texture a house, you just can't.
I think it would be a matter of adjusting UV ccordinates for surface base objects so it can be done.
Also, generic customizable vehicles (some sort of trains) that could have a predefined path with multiple nav points,
could ressemble traffic. You could have either loop path (it disappears at the end and reappears at the beginning) or
just the conventional train route where vehicle turns back (like a car) or not (like a train).
Also, I have noticed in Stellarium that sun looks big inside Earth atmosphere during daylight.
I was wondering if it could be done. It could be interesting to ressemble such an effect for other planets (Titan for
example).
Also, for planets, it could be interesting to have an atmospheric blue effect for distant objects like mountains.
It would add to the feeling of distance.
For terrain, I came to think that you might define points of a grid with a certain resolution.
As you fly, points are unloaded and the points in front of you are loaded, so you do not spend too much memory with
terrain points. Let's say that you draw big terrain for a 120 km square, with a 20 meter resolution, 1 byte to
represent altitude, you would have 35Mb of RAM used for such data.
I bet it probably was already in your mind, but I had to say it.