Night lighting - Terrain emits light?

There is no tweak, but you can disable sepia mask see here DEV Night Light

My example was with and without sepia mask from my link.

how did you select 25% mask then? photoshop?

yes photoshop, just to show with the team some result, because they have access to the globe world night texture (sepia), but not photoshop used on the first initial test link.

1 Like

Night sky seems more blue than black, it’s not terrible, but could be improved to make it more realistic. Agree also, the moon light could do with a tone down. Personally i think it currently emits too much light.


Yeah, and don’t forget the police cars overtaking on highways, I love those kinds of details in X-Plane.


Vote this thread, near the title at left, press vote, will affect night light as well on LOD ground texture + building “Ground texture - Low resolution - Internet incorrect Bandwidth


How does night terrain with the tweak look like at FL350+??
As I knew, with only 3D point lights without LIT textures (aka sepia filter), draw distance must be severely restricted like in early version of XP11 (before 11.20), where only a very small square of some point lights was following you directly under your plane, anything other than that square the whole terrain was completely dark. Experience of being early XP11 user taught me that we definitely need LIT textures as a “cheap solution” because the coverage should reach million square km at higher altitude.

I think the best solution for MSFS should be using higher-res satellite photos for night terrain, which is not easy to apply in global scale.

The second best might be pre-generating LIT textures from in game 3d point light sources, using top-down drone cam or similar method in automated batch, and use it as replacement of current sepia textures so that my poor cpu don’t have to render too many expansive 3d point lights in real time.

Hi guys, the first half of this post is not really related to the Sepia Mask (ground emitting light), but an equally important part to why current night lighting doesn’t really make it to the finish line.

Good posts, but what you say in the above quotes is NOT the way to go, as I think you misunderstand the way the current lamp tech works.

First, you can’t “exclude” lamps from render scale, that’s not how render scale works.
Render scale is pretty much rendering the whole scene at a different resolution, and then resampling the whole scene back to your selected resolution.

For example, native res 1080p, render scale 200:
This would mean 200% render resolution. in other words, render scene in 4k, and then resample back to 1080p. This will give you sharper/betterlooking edges, less noice and pixelation. But also trick the render-engine to pick a higher mip-map in the texture, usually having less transparency, making it more visible.
Taking a 4k scene and resampling it down to 1080p is the same as running a 1080p scene with 200 render scale in this aspect.

"excluding" lights from render scale, if it was possible, would leave you with exactly the same lights you had from the beginning.

Lamp sizes should NOT be bigger, that’s the wrong way.
Doing so, you adress the symptom, not the problem.

What we see is what I believe is at least a two-fold problem.
Renderscale is not the cause, just a way of exposing the problem.
First, you have the TAA anti-alias mode “eating” lamps, especially visible in lower resolutions.
Here’s a night scene without Sepia Mask: “Only Lighting” selected in Dev-Mode.

As you can see, lights look different depending on both resolution and AA-mode.

With brightness-increase, you can see TAA mode adds a “dark halo” around the lamps,
shrinking them a lot! Increasing lamp size would be the wrong way to go.

Here you can see the lamp bulbs is already huge, look how they look in distance,
enormous blurry orbs… Increasing the lamp sizes would make it look even more ridiculous in the distance, it’s better to attack the problem instead of just the symptom.




Now to the other issue, which I believe is a mip-map issue in the lamp/bulb-texture.
Here’s a typical lamp bulb texture, when you include the mip-maps.
The alpha channe (transparency) follows the same pattern

The “mip” selected depends on how many pixels the lamp-billboard/sprite occupies in the scene.
When lamp is close and occupies a big number of pixels, the bigger “mip” is selected from the texture.
and when the lamp is tiny in the scene, and occupies just, lets say, 5x5 pixels, a very small "mip"is selected, with less transparency. This helps to fade the lights into the distance.

But if you double your rendering resolution, let’s say from 1080p, either with higher render scale 200, or setting resolutionto 4k, the same lamp now occupies 10x10 pixels, and therefore a bigger “mip” is selected, with more brightness and less transparency, making the lamp brighter/less transparent , more visible

Look at this 4k vs 1080p comparison. I first thought low resolution didn’t render lamps at same distance as higher resolutions. But look what happens when I increase the brightness in the 1080p version:

The distant lamps almost disappear in the 1080p version! But increasing the brightness, you can see that pretty much all lamps are still rendered!!! but with much lower transparency!
(This is exactly what happens to the lamps when adjusting the render scale too)

Here’s a screenshot from early Alpha, before they reduced lamp visibility and introduced the Sepia Mask, compared to current release build. Note the visibility of road-lights, also bulb-style with glow.

As you can see, the distant streetlamps in the horizon are completely gone… Like the city suffered a power outage.


I’ve been trying to “bring back” the lamps using photoshop:
First, how MSFS looks close to LA downtown in 1080p Ultra.
Secondly, a modded screenshot where I pull the lamps from 4k resolution and resize back to 1080p, to circumvent the “bugs” causing lamps to disappear way to early in lower resolutions. Also, adjusting hue/saturation/lamp-size and finally reintroducing the “glow” around lamps. Nothing has been done to the Sepia Mask.


Here are closeups comparing the MSFS lights (getting eaten by TAA anti alias mode) and my modded lights trying to make them more “lamp-y” bringing back the glow and color. Not that I haven’t increased the size, I’ve just disabled TAA and downsampled 4k lamps to the same resolution.
In other words, no size increase, just “removed” what’s “eating” the lamps in the first place.



Now, addressing the problem in this bug report, the terrain emitting light:

Here’s some of what I think looks highly unrealistic with the current night lighting.
The infamous “Sepia mask” being implemented sometime during the later alphas simply looks like you’re taking the daytime satellite photo and just applies a low-res lightmasked sepia-filter to it…
Watch this video…

This effect is applied is using the very low-res night image you can see in the world map when planning a flight, often illuminating lots of terrain and features that IRL would be pitch black:

Here’s a photo of Dubai at night, compared to MSFS, same location 30,000 ft at night.
As you can see, the MSFS desert is glowing in the dark! And the bright highways from the photo, is pitch black in MSFS.
It is pretty much the opposite / inversion of what it looks like in reality.
This is a big problem as it is implemented worldwide, but some places looks worse than others. But if you understand how current night tech works, and how it really should look like, it’s easy to spot.

Here is another comparison, sepia mask over Berlin, plus snow comparison, to show that lights should come from lamps and roads only, and not illuminating terrain for miles around it.

I personally believe the now infamous “Sepia Mask” should either be reduced to below 30% when not viewed at a very shallow angle (far distant in the horizon), or more preferably, replaced with a night texture layer consisting of baked light splashes based on existing MSFS lamp bulb positions. This would save a lot of FPS compared to letting each lamp in the distance illuminate the ground. This would only need to be done at very close proximity where trees and buildings are present.

Here’s an example, Stockholm at 30,000 ft in MSFS. Compared to a “light splash” texture generated with QGIS software and OSM road vector data, placing illuminated colored “splashes” along the road vector data. This texture can be lower resolution, since the splashes are blurry by nature, and applied on top of the satellite photo texture. And with MSFS having coordinates for all those lamps present, this can be used for procedural generation of global textures. It has been done even for FSX addons, “Night Envirenment” series and “Black Marble”…

This is definitely closer to the Berlin photo earlier in this thread, where it’s the actual street lights illuminating the scene, and not some low resolution mask illuminating miles of uninhabited adjacent terrain, like we have now in MSFS.



Hope this clears some things up!


There is several way to do it, “complex or easier”, but before there was no sepia mask used and light size was larger on earlier build. I don’t know which route the team want to go and what is possible.


Absolutely, just pointing out why lamps in some cases look smaller, and why increasing size won’t fix the problem as the scaling seems different, as well as changed texture style. Medium and long distance lamps would become even bigger and look worse than the enlarged orbs I showed you earlier.

Let’s fix the problems, not the symptoms as that might create as many problems as it fixes.


Wow! I’ve noticed this effect at night, and you provided an excellent explanation of whats going on! So if I read you correctly, that last photo of Stockholm with the vector light data, could be what night lighting may potentially look like had the team followed the guidance you suggested in your post?

Just starting to do some high altitude night flying in the sim, and what you are showing would be a MASSIVE improvement! For a sim that looks so stunning in the day, it should be equally as good at night!

What I find the strangest, is how the night lighting actually looks better in the earlier builds. Makes me wonder why they even bothered changing it?


The screenshots of the distant lights is one of the biggest selling points for me. Looked incredible. I sure hope they fix it because right now, it doesn’t look good at all compared to early access.


@Grinde81 - this is awesome explanation and truly appreciated. I really hope the devs read this and contact you to get this resolved! :slight_smile:

@Jummivana @Skeedorr @OlieTsubasa443 - Just want to highlight this amazing explanation from Grinde81 and bump it to your attention to bring it up with Asobo / Dev team … This will truly enhance the night experience in the Sim…


Thanks for this very detailed report !


I agree and in all case, improvement can’t be step back then currently, not even :pinching_hand:, it’s probably the worst we can have with the sepia currently.

Thank you for all your effort!
did you generate the data and texture for that last Stockholm photo? and if you did then can you generate same for Dubai and share it?

1 Like

This bug is now in the top 3 :

    1. live weather (aggregate of 3 threads)
    1. G1000
    1. Night lighting : terrain emits light

Can’t wait to see what the devs will answer about it, but as a beginning please make it possible to tweak night lighting parameters via .xml (or similar).


That’s a brilliant, fascinating and insightful analysis of the night lighting issue - thank-you!

Clearly shows that the software has gone backwards since early development versions.


I don’t have that data currently, but here’s a high-altitude screenshot of Dubai from ancient FSX with “Night Environment Dubai” addon, afaik the exact same method of procedural generation of “light splash” textures using OSM road vector data, different lights colors and sizes for different road-types.

In terms of realism, this comes much closer to the photo and reality compared to current MSFS sepia mask. The light comes from streetlights only, illuminating busy highways & smaller streets as well as smaller residential roads, instead of hanging a big brown lamp over the whole area illuminating the entire satellite photo evenly.

And this is most probably how MSFS placed all its current light bulbs, so half the job is already done if they would pursue this method.

If I’m not completely wrong, Night Environment addons was made for most european countries, few asian ones and a couple of US states, by a enthusiast one-person “team” , so I have no doubt the team of skilled artists & developers at Asobo could create an even more realistic version of this.


Thanks for your reply. The problem with MSFS is that they use warm lights everywhere which is wrong as most of the suburbs are warm lights and then major roads, high ways and roundabout are warm color and those red splash everywhere looks so ugly

I hope they fix this issue or at least make it easy for us to edit lights

1 Like