Diagnosing Morrowind light pop-in

General discussion regarding the OpenMW project.
For technical support, please use the Support subforum.
User avatar
psi29a
Posts: 5025
Joined: 29 Sep 2011, 10:13
Location: Belgium
Gitlab profile: https://gitlab.com/psi29a/
Contact:

Re: Diagnosing Morrowind light pop-in

Post by psi29a » 25 Jan 2021, 11:56

Amenophis wrote:
24 Jan 2021, 14:58
I'm just tested on latest nightly on Linux. The light pop in still there for years now.
Light 'popping' in this way has been there is only even more noticeable in 0.47 because of distant statics (object paging). We're not ignoring the problem though, just that other things have taken priority.

As pointed out by Nobby, there is a WIP branch that tries to resolve the problem but the author is sick and can't further the work for now. Hopefully someone with the time and ability can pick it up.

clort
Posts: 12
Joined: 25 May 2019, 06:18

Re: Diagnosing Morrowind light pop-in

Post by clort » 04 Feb 2021, 06:03

Probably worth noting that Aldruhn Mages' Guild is one of the worst-lit sites in the game. Experimenting with reduced light falloff starkly reveals that the lighting affects the surrounding room more than objects and NPCs placed in it:
Image

Here it is with default linear lighting settings, on my aarch64 computer, january's git master. Here's an animated png showing the extreme color curve needed to bring things into visible range:
Image

As the ever-helpful folks have commented already it's that per-object vertex lighting that can't be coaxed into a sensible result via openmw settings.

If one section of wall is a different object, it sees a different set of room lights:
Image

Trying constant lighting,

Code: Select all

fallback=LightAttenuation_UseConstant,1
fallback=LightAttenuation_ConstantValue,0.000001
fallback=LightAttenuation_UseLinear,0
NPCs still remain dark for some reason:
Image

I think we have seperate nasty issues playing together:
1) As per thread title, OpenGl + OpenMW doesn't fade object brightness, brightness 'pops' to black (this may be an OpenGL bug)
2) The surrounding room is counted as being 'close' to light sources placed in the room, while smaller objects (tables, benches, NPCs) are 'far' from those sources and hence very dark.
3) Objects in a room receive no [correction - just a tiny little bit of] ambient light, they seem just lit by whatever directional, placed light sources are hitting them. NPCs are often just unrecognizably dark. We could address this by adding a non-directional ambient brightening to these objects without bringing-in the heavy guns of a modern lighting engine. Alternatively we could add a dim, high-range light to the player (or camera) position as 'fill lighting'.

[EDIT]
what the smart folks are saying: https://gitlab.com/OpenMW/openmw/-/merge_requests/232...

User avatar
psi29a
Posts: 5025
Joined: 29 Sep 2011, 10:13
Location: Belgium
Gitlab profile: https://gitlab.com/psi29a/
Contact:

Re: Diagnosing Morrowind light pop-in

Post by psi29a » 04 Feb 2021, 09:51

What the developers are saying:
https://gitlab.com/OpenMW/openmw/-/issues/5828

clort
Posts: 12
Joined: 25 May 2019, 06:18

Re: Diagnosing Morrowind light pop-in

Post by clort » 05 Feb 2021, 01:09

Just to make this findable to this thread as well: Morrowind interiors are usably bright. On my box OpenMW interiors are often not.
Image

I've been told that Morrowind also does not use more than 8 lights. I'm curious what can be done for brighter interiors short of a lighting engine re-write.

User avatar
AnyOldName3
Posts: 2095
Joined: 26 Nov 2015, 03:25

Re: Diagnosing Morrowind light pop-in

Post by AnyOldName3 » 05 Feb 2021, 02:50

This site says some Intel drivers for Windows set GL_MAX_LIGHTS to 16 instead of eight: https://feedback.wildfiregames.com/repo ... MAX_LIGHTS
AnyOldName3, Master of Shadows

User avatar
wazabear
Posts: 32
Joined: 13 May 2020, 19:31
Gitlab profile: https://gitlab.com/glassmancody.info

Re: Diagnosing Morrowind light pop-in

Post by wazabear » 28 Mar 2021, 22:07

clort wrote:
05 Feb 2021, 01:09
I've been told that Morrowind also does not use more than 8 lights. I'm curious what can be done for brighter interiors short of a lighting engine re-write.
Hi, so I've been working on some light fixes. It's currently a MR on Gitlab if you're interested in testing it out :)

https://gitlab.com/OpenMW/openmw/-/merge_requests/618
Fade away and radiate

Post Reply