Diagnosing Morrowind light pop-in

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psi29a
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Re: Diagnosing Morrowind light pop-in

Post by psi29a »

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
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Re: Diagnosing Morrowind light pop-in

Post by clort »

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...
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psi29a
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Re: Diagnosing Morrowind light pop-in

Post by psi29a »

What the developers are saying:
https://gitlab.com/OpenMW/openmw/-/issues/5828
clort
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Re: Diagnosing Morrowind light pop-in

Post by clort »

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.
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AnyOldName3
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Re: Diagnosing Morrowind light pop-in

Post by AnyOldName3 »

This site says some Intel drivers for Windows set GL_MAX_LIGHTS to 16 instead of eight: https://feedback.wildfiregames.com/repo ... MAX_LIGHTS
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Re: Diagnosing Morrowind light pop-in

Post by wazabear »

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
clort
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Re: Diagnosing Morrowind light pop-in

Post by clort »

wazabear wrote: 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
Thank you. I will put it in my TODO queue.
[EDIT]
Reviewed the whole discussion. Those opposing this MR are wrong. The original Morrowind lighting was a horrid hack and your work improves OpenMW substantially.

Getting things to 'look nice' is now the job of OpenMW modders. Particularly on the subject of that cursed mages guild. ;)
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Re: Diagnosing Morrowind light pop-in

Post by wazabear »

clort wrote: 11 Jul 2021, 23:22 Reviewed the whole discussion. Those opposing this MR are wrong. The original Morrowind lighting was a horrid hack and your work improves OpenMW substantially.
Thanks. There was no opposition to the MR, just some concerns about how this changes visuals. There is still a big leap we need to take with lighting, and that's introducing clustered forward rendering. It will pretty much eliminate our lighting concerns, but nobody has seem interested in adding it and I am working on other things which I believe to be more important.
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