How would I create a transition from space to a planet's surface?

Hello, I am developing a game that will involve traveling between planets and exploring them on their surfaces. So far, the biggest problem I have encountered in my research on how to create the planets has been placing foliage on the planet’s surfaces. The planet meshes will be spheres split into chunks. I know that foliage could follow a perfect sphere using align to normals, but these spheres will have terrain on them and I want the foliage to appear straight while on the surface, not aligned to individual hills and valleys. How should I go about doing this? Is there a way to paint foliage so that it points straight out from a specific point or something like that?

I have actually encountered that method before and really liked it, but I want players to be able to enter the planet’s playable surface area from any point. This game is going to be multiplayer and if it weren’t for that, I could probably just stream in the playable area with a transform that places it where the player is going to enter, but if I implemented this in multiplayer, nobody’s position would be correct relative to other clients.

Another idea I had to possibly make it work would be to have some kind of transition effect happen between rendering levels. In a tutorial I found for accomplishing something very similar, they applied a circular mask to the more detailed surface area which blended ut the edges, making a smoother transition between that area and the larger model. That made me wonder if I could do some kind of crossfade effect starting from the center of the screen and moving out, or maybe even just a regular crossfade, as I open the ground level instead of having a stark level switch. But, I have no idea how to go about this either and my research has come up very short.

All of this is why I began considering spherical levels, but figuring out the crossfade effect, or some other way to get a system like the one they showed off with the sky and atmosphere to work from any approach and in multiplayer, would be ideal.

Actually, I just had another idea that I can try, which is a combination of a tutorial about crossfading cameras and everything I have seen on how the portals were made in the portal games. I could try streaming the surface level in a separate area. A second camera and a fake player model would be mimicking the rotation of the true camera and player above the area where the flat map will stream in. The second camera’s location over the flat-level would be determined by some math I will have to figure out that would convert the polar coordinates of where the player is in relation to the planet’s sphere to a spot over the flat map. As the player gets close enough, the flat level would stream in and a crossfade would start from the main camera to the second camera and, when the fade finishes, the main camera, and the player would be teleported to the exact locations of the fake player and second camera which would then be disabled until they are needed again.