I am updating my group’s headquarters, a ~2600 stud tall skyscraper located around Tokyo. I am currently using a normal Sky inside Lighting, but as you can see in the picture below, which was taken from the helipad at the top, it looks almost like the player is still on the ground.
I think your only options right now are to create a custom skybox (crop it so only the tops of buildings show or find a different picture) or have the normal sky but build very low-brickcount skyscrapers in the background far away from where the player is.
You can also have someone design a skybox for you, but it seems to me that you want a photorealistic skybox so not sure you’d want to do that option.
Skyboxes are meant to display the sky and objects such as clouds. These are usually distant enough to not need to move. However, skyscrapers and other objects are relatively very close to the player in a game where you are playing on a skyscraper, and their position relative to the player needs to change as the players climbs up.
Embedding a cityscape into the skybox isn’t going to provide you with the effect you are trying to achieve. Instead, you can build low-poly skyscrapers that you place around your main HQ building and add some skyline textures behind those buildings to transition to the flat skybox.
Alternatively, if you really want to use a skybox, you can choose one that has the buildings at a greater distance from the player. That way, the illusion of depth remains intact as the buildings are not expected to move around. Here’s a visual;
That sort of setup should provide you with accurate distance views when looking outside of windows inside of the building, and give you a cool view when looking down from the top.
Basically you can just drop a model / building within the ViewportFrame (It would require you to construct a basic city mesh / build), and it should appear in the ‘skybox’. However it’s more of a hack, so I would play around with it for a bit to see if it would work in your situation.