First, have a small room built, lit, with player start.

Make a subtracted cube.

Don’t put it around the terrain, etc. Place it off to the side.

2048

4096

4096

Put cloud textures on all sides, or, a black texture top sides and bottom. You can make a black texture in Photoshop, 100% black at the size of 16x16.

To the top face, [or, all sides] apply sky image 256 square.

Align the sky to face, U and V Tile to 2.

Here comes SkyZone Man

Actor Class Browser:

Actor/

Info/

ZoneInfo/

SkyZoneInfo/

Top viewport, right click center of skybox and add.

In other viewports, move or make sure your actor is centered inside the skybox.

Lighting

Create about 8 lights to evenly illuminate your sky.

Work in Perspective

Select whatever plane you want to open to the sky.

Right click properties and make these settings:

Hit Build.

Right click the perspective viewport/view/show backdrop

Set to view realtime

Play level ... you will see the sky slowly crawl across the surfaces ... we need to fix the corners ... let’s use fog ...

Right click properties and set distance fog to true.

Set up the fog color, and the fog start and end.

Play level.