Zesterer's Volumetric Cloud & Mist Mod for OpenMW

A mod that adds raycasted volumetric clouds to Morrowind.

The goal of this mod, aside from looking pretty, is to enhance the perception of the world's scale. High view distances are great, but they ruin the sense of immersion and mystery. Equally, a low, static view distance has the opposite problem: you never get the opportunity to see the sights. With this mod, you'll experience the best of both worlds: mystery and intrigue, with occasional moments of wonder when the mist clears and you can see for miles.

Screenshots

Note that these screenshots were taken with additional mods installed, such as Morrowind Rebirth.

More screenshots

Features

• Clouds: Realistic, volumetric, raycasted clouds that move, swirl, and change in real time as you play
• Mist: Low-lying mist that comes and goes throughout the day, altering the effective view distance dynamically
• Rayleigh scattering: Light realistically attenuates as it moves through the atmosphere, improving the sense of depth and scale
• Weather: Both clouds and mist properly react to in-game weather conditions in a realistic way
• Point glow: An effect that adds diffuse glowing aura around light sources, dynamically changing according to mist cover
• Interior mist: An effect that emulates dust and water vapour in interiors
• Improved skybox and sun rendering: Adds a little flair to Morrowind sunsets
• Many configurable settings: Pick and choose what features you enable or exactly how your game looks

Recommendations

• This mod works well with my shader set.
• Enable distant terrain
• Whack the viewing distance up as high as it can go. I use a view distance of 300,000.
• Ensure that distant fog is disabled (this mod supersedes it)
• Enable the FXAA post-processing shader (make sure that it comes after clouds in the render order)
• Disable or reduce MSAA (post-processing effects do not play well with it, so you're usually better off just using FXAA)
• The point glow effect works best with Hemaris' 'Improved Lights' mod

Installing

Ensure that you have the latest development build of OpenMW. If you find that the mod does not work with the latest development build, please open an issue!

1. Download the shaders.

2. Extract the shaders somewhere. I'd strongly suggest extracting next to your openmw.cfg file.

3. Add a data entry to your openmw.cfg, as with most asset mods:

data = "path/to/openmw-volumetric-clouds"

(Ensure that the openmw-volumetric-clouds directory contains the shaders and textures directories)

4. Enable post-processing shaders in your settings.cfg.

5. Start OpenMW and have fun!

Enabling the mod

1. Open the in-game 'Options' menu and enable 'Post Processing' in the 'Video' tab.

2. Press F2 to open the in-game post-processing menu

3. Click on 'clouds'

4. Press shift + right arrow key to add it to the active effects list

Configuration

The mod comes with a variety of configuration options. You can:

• Change render quality (lower quality means higher performance)

• Alter cloud density

• Alter mist density

• Toggle an additional 'swirling' effect that makes mist more realistic and interesting to watch

• Toggle clouds on and off

• Toggle whether the vanilla skybox is visible behind the clouds and mist

Performance

Performance may be an issue for some machines. The mod includes a variety of settings (available in the aforementioned F2 menu) that allow reducing the quality or disabling various features in order to improve performance. At minimum settings, even the lowest-powered machines should be able to run the mod.

Implementation

• Both clouds and mist are rendered using raycasting, meaning that they are 3D elements of the environment: you can walk through them and they swirl, shift, and move in real time.

• Although all code is new to the mod, many aspects of the implementation are borrowed from my work on Veloren's cloud shaders.

Known issues

• Rain is applied before post-processing shaders and don't write to the depth buffer, so clouds appear over rain drops

Inclusion in mod packs / mod lists

I'm happy to have this mod included in mod packs and mod lists! However, open-source is a two-way street and there are a few things I'd request you do if you decide to redistribute this mod:

Let me know about it

It's nice to know when my mod is included as part of other mods and it's often a useful way to discover possible improvements, incompatibilities, or bug reports from other users. I'd appreciate you opening an issue/discussion thread here, or dropping me an email. I'm regularly active (even if the mod hasn't been updated in a while) and usually respond to most things within a few hours. I'm also active on Mastodon and Discord.

Keep the mod up to date

Nobody likes dealing with bug reports, especially when those bug reports turn out to be for problems that have been fixed already. I'd appreciate it if you make sure that you do your best to regularly update this mod for the duration of the mod pack's life, ideally so that the version users end up installing is no more than a few months old.

Encourage users to report bugs here

Bug fixes are good! It's even better if everybody that uses the mod can benefit from those bug fixes. If you or your users find a problem, I'd appreciate it if you could try to report it here so that I can fix it. It's no good a bug report appearing on a mod page somewhere I'm not aware of, leading to it never being fixed.

Upstream patches and improvements

Have you found a fix for a bug, or a nice improvement you think might be worth adding to the mod? Open a pull request or let me know about it! Even if you don't know how to use git/GitHub, you can still describe the fix in text and/or send me an email about it. When patches make their way upstream, everybody benefits: not just the select group of users using your specific mod pack.