offing

offing draws the land beyond your render distance. every chunk the game has ever shown you leaves a column behind: its height, the colour of its top block and the block under it, whether it is water. from those columns the mod builds a low terrain, a rolling heightfield with grass on the slopes and dirt where it is steep, lit by the real sun, dark under the real night, and hangs it out to a thousand blocks where the game's own fog would otherwise end the world.

it remembers. columns go to disk per world, so a coastline you walked last week is still on the horizon when you come back, before a single chunk has loaded. it costs a few milliseconds a frame on the mac it was built on, runs on both of minecraft's render backends, and needs nothing from the server. what you have not seen stays sky.