[Dev Builds] Eternity sky rendering improvements

[printz]

^{All topics tagged with [Dev Builds] are going to be about new stuff you will find in Eternity development builds. Since the official release cycle is quite slow, you're encouraged to try development builds such as from DRD Team's website. Usually they come one day after the post.}

 

After a bit of figuring out how to solve various conflicting issues with the sky rendering in Eternity, which is all software mode, we've managed to untangle it in the following ways:

1. Sky stretching is no more! Instead, when the player looks up, the sky gets faded to a single colour. All the landscape skies now fade nicely to a single sky colour without tiling or stretching. Certain skies such as starry space ones may look not so good, but hey, those wads were made without freelook in mind (and it would look wrong for stars to repeat anyway). This is of course inspired on how software-mode GZDoom solved it. NOTE: vertically scrolling skies (as in MBF sky transfers combined with scollers) will still tile all the way. All this means that the menu option, the console variable and the OPTIONS field of r_stretchsky/stretchsky have been deprecated/disabled.
2. Looking up and down in Doom is now ±45 degrees. It used to be already so in previous devbuilds, but it caused some unwanted problems. But now it's safe to be back to ±45 degrees. Keep in mind that Doom wasn't meant in the first place for freelook, this is an optional gameplay extension. In Heretic, since it was made for freelook in mind, it has been preserved at ±32 degrees. This way its skies still look properly and you don't gain an unswitchable gameplay advantage. You can now change the max view pitch in mods in EDF game properties.
3. Fixed the way PrBoom-compatible tall skies rendered differently in PrBoom+ versus Eternity. This affected wads based on popular texture sets like OTEX. Now Eternity autodetects how they should render (if the tall skies were merely part of TEXTUREx/PNAMES replacements versus if they were set in EMAPINFO), so if for example those skies covered the entire 0-pitch screen in PrBoom+, they'll do the same in Eternity.
4. Added options in EMAPINFO to adjust the sky drawing height for tall skies. You'll need 260 for ±45 view pitch skies, 200 for ±32 view pitch (Heretic-like) or 100 for vanilla-like (by default it will autodetect from 0 or 200, for compatibility's sake).

Here's a gallery:

 

Short sky fading to a median colour:

 

 

Tall sky (from OTEX), set merely via PNAMES/TEXTUREx, rendering the same as in PrBoom+ (only in Doom mode), instead of being shifted up like in Heretic:

 

 

Edited October 16, 2021 by printz
added detail about scrolling skies

[HavoX]

All right! Now that's what I call progress!

[kinker31]

This isn't related to skies, but definitely related to mouselook/freelook: If it's possible to do so, will perspective correction be available in the next Eternity release?

[printz]

On 10/17/2021 at 5:00 AM, kinker31 said:

This isn't related to skies, but definitely related to mouselook/freelook: If it's possible to do so, will perspective correction be available in the next Eternity release?

If you mean a rendering mode that avoids y-shearing, probably not. What we surely need (or what I would like) is hardware rendering to power the Strife: Veteran Edition maps, so that would also be the solution to this problem. 

 

As for software rendering with true 3D rendering: that's a complex subject. Maybe GZDoom has something, if it's free. Not sure.