Sky Position Shifted

[Tarnsman]

After downloading the latest build I started noticing a lot of skybox oddities that were previously not there.

 

It looks like all the skies got shifted up 32 units, which causes some obvious skybox issues with many existing wads.

 

 

[printz]

That's because Eternity now lets you look up 45 degrees instead of just 32 degrees like in Heretic, so skies had to be extended and stretched to be able to fill that new gap. The rule is a bit more complex, in the code, but some notes I can write:

 

- Heretic skies wrap around at the horizon, not below it, like Doom.

- Previously the full height was 200 (after which it starts to grow downwards). Now it's 260. This means that any previous skies which were supposed to grow down from 200 to 260 now grow up to fill up that stretch space. Only after getting past 260 units tall they continue down. I suspect this is the problem: if you have some round value like 256, it will grow in the wrong direction since that update. 

 

I wonder how to solve it. 

 

EDIT: A possibility is to retain the old behavior. Skies taller than 200 to grow down instead of up (as expected by the wad), and remain permanently stretched to fill the 260 look-up space. It's not ideal, it's slightly degraded, but not as bad looking as stretching small Doom skies. 

Edited June 3, 2021 by printz

[Tarnsman]

Whatever behavior retains the old positioning of sub 260 skies would be ideal as many existing WADs have things within the maps based around the position of things in the sky (most commonly a source of light for shadowcasting).