This is expected behavior. Previous versions of Unity would constantly re-bake environment lighting automatically, if no manual bake has been performed. That behavior was changed after Unity 2022. Now you have to bake manually. Just press Generate Lighting and the environment lighting will reappear.
How anyone sane could design this as expected behaviour? So⌠lets say i want to clear all lighting to its default state. How should i proceed? Because clearing baked data (which was intuitive enough in previous versions) is clearly not working
In case anyone else comes across this: this is almost certainly a bug. It appears that after clearing baked data, the Lighting>Environment>Environment Lighting>Intensity Multiplier is set to â0â, even if its slider is showing a non-zero value. Dragging the slider to a different value, and then back to the intended value corrects the issue.
Before baking, Unity uses real-time lighting, where the intensity multiplier directly affects the light sourceâs color, usually defaulting to white for standard, direct illumination
I donât think people understand the issue. Its got nothing to do with what âshader modeâ your in.
This is a real-time baking issue regarding the lighting URP and Lighting rendering real-time pipeline.
If you bake a light the entire scene goes from real-time to baked. you cannot access and or modify in real-time the intensity modifiers for both reflection and lighting. This then negates the real-time lighting illumination and you are then forced to rely on baked texture maps from the skybox and other lights in the scene.
There seems to be no way to revert the back and go back to real time lighting. Even if you âmimicâ and re-bake to identical settings, it still doesnât work.
You are then stuck from then on to bake every new light you add to the scene.
This is not ideal, and many are asking why is this an issue ?
Is there a way to revert back to real time lighting in the scene - using the intensity modifiers in âreal-timeâ ?
Unity 6.3 LTS - 6000.3.1f1. This is so broken its not even funny.
Same issue as everyone else - clearing baked data makes everything black, even when Iâm only using a single realtime directional light. If I press âGenerate Lightingâ as Pema-Malling suggests, it tries to bake lights as if theyâre not realtime lights (but they are in fact realtime lights) - extremely long process - âBaking global illumination 20 minutes leftâŚâ.
None of the âfixesâ have worked for me.
Iâm using URP.
Edit:
I just let âGenerate Lightingâ fully run with the realtime directional light. I now have a gigabyte of baked lightmaps and the textures in my scene are fully shaded.
This is nuts. Please fix this.
It sounds to me like your scene is misconfigured. From what you wrote, I assume your intention is to not use lightmaps (or any other kind of baked GI).
The âGenerate Lightingâ button will only produce lightmaps if you have objects in the scene that are requesting lightmaps. Such scene objects meet 2 criteria:
- They have the âContribute Global Illuminationâ flag enabled
- They have their âReceive Global Illuminationâ mode set to âLightmapsâ
If you didnât intend for these objects to receive GI from lightmaps, you can change the âReceive Global Illuminationâ mode to âLight Probesâ, then they will no longer request lightmaps.
If you didnât intend for these objects to affect baked GI at all (or didnât intend to use baked GI in your scene), you should disable the âContribute Global Illuminationâ toggle. Scenes that contain no MeshRenderers with this toggle enabled will generate 0 lightmaps.
Iâll try to demonstrate the expected behavior if you just want lighting from the sky. I used the exact Unity version you mentioned. Letâs start with the default URP scene. It contains nothing but a realtime directional light and a camera:
I will change the lightâs color to red, and add a plane to the scene so we can see the lightâs contribution:
If I now open the Lighting Window and press the âClear Baked Dataâ button (under the dropdown on the âGenerate Lightingâ button), the appearance changes:
Why does it change? Because the default URP scene ships with some pre-baked environment lighting data that matches the default skybox. Clearing the baked lighting will remove this.
At this point, I can still modify the light color, and the appearance updates in realtime:
If I now click the âGenerate Lightingâ button, the appearance changes again:
This is because the environment lighting data has been now been re-baked. At this point, I can still change the light color in real time, which makes sense since it is a realtime light - it will never be baked:
Now lets say I want to change the skybox. If I do this, the appearance now looks off, because the baked environment lighting data doesnât match the new skybox:
However, if I press the âGenerate Lightingâ button again, it will be re-calculated to match the new skybox:
At this point, I can still change the color of the directional light in realtime. The intensity multiplier works as well:
Because the plane doesnât have âContribute Global Illuminationâ enabled, I can also modify the Intensity multiplier for the lighting from the sky in realtime:
However, if I enable âContribute Global Illuminationâ, and then âGenerate Lightingâ, the plane will receive a lightmap. The contribution from the sky will be baked into that lightmap, which means that modifications to the environment intensity wonât do anything anymore. Any object that doesnât have âContribute Global Illuminationâ enable can still have its sky contribution modified in realtime, though. I added a cube with âContribute Global Illuminationâ OFF so you can see this:
If I modify the directional light color, both the cube and the plane will change appearance, even though one of them has a lightmap. This is because the directional light is set to âRealtimeâ:
If I set the light to âBakedâ, then âGenerate Lightingâ, I can no longer modify the color in realtime, and the light stops affecting the cube. Baked lights will only contribute to objects that receive baked GI either through lightmaps or light probes:
Finally, if I âClear Baked Dataâ at this point, I can modify the light color in realtime and see it affect both scene objects again:
This is because, until a scene has been baked, all lights are treated as realtime lights. When you âGenerate Lightingâ, lights that are set to âBakedâ stop acting as realtime lights. This is mainly to help when authoring, like f.x. placing a spot light, to prevent having to constantly re-bake to get an idea of what the light will affect.
So, in summary, if you donât intend to use baked GI, my advice is to disable âContribute Global Illuminationâ on every object, set every Light to âRealtimeâ mode, then press âGenerate Lightingâ to bake just the contribution from the skybox.
There may of course be bugs lingering in this area. If you are seeing behavior locally that doesnât match what Iâve shown, please let me know. I hope some of this helps 
Please let me know if my post just above clears up the issues you are seeing or not.
To help clear up confusion, I want to make it a bit more precise what we mean by âBaked GIâ and âBaked Environment Lightingâ.
In Unity there are, roughly speaking, 4 kinds of light sources:
- Lights with mode set to âRealtimeâ
- Lights with mode set to âBakedâ
- Lights with mode set to âMixedâ
- Light from the skybox, also known as environment lighting
When I say âBaked GIâ, I am talking about contribution from âMixedâ or âBakedâ lights, after pressing âGenerate Lightingâ. This contribution is stored in either lightmap textures, or in light probes. Until the âGenerate Lightingâ is pressed, all lights act as if they were âRealtimeâ, so there is no baked GI.
Light from the skybox is special - even if your scene doesnât use Baked GI at all, you still need to bake the contribution from the skybox, or it will have no effect on lighting. Pressing the âGenerate Lightingâ button bakes this skybox contribution into a fallback reflection probe and a fallback light probe, often called the âambient probeâ. This data is what I call âBaked Environment Lightingâ.
Scene objects that receive no baked GI from lightmaps or light probes will still sample this baked environment lighting. A scene with no baked baked environment lighting available, and no Realtime lights present, will appear fully black.
Pressing the âClear Baked Dataâ button in the Lighting Window deletes both Baked GI data and Baked Environment Lighting, resetting the scene to a state where only realtime lighting is present.
Workflows for environment lighting arenât great at the moment, itâs something we are looking to improve for URP. That said, Iâm unsure if I have seen anything in this thread which would be considered a bug. If you think I am wrong about that, please let me know, so we can get it fixed. Pictures help a lot!
Yep.
The first image in the picture is original lighting, before being destroyed by âGenerate Lightingâ. The other three images are my attempts to get back to normal, realtime lighting.
Iâm having the same issue as you, and I found this thread in my 18+ hours of attempting to fix this. pressing one button (generate lighting) destroyed the lighting for my entire scene and it has been impossible to go back, essentially bricking hundreds of hours of work. From pressing a button. On the UI. Of the program Iâm using. Frankly, Iâm amazed that a program is so easily able to undo this much progress at the simple click of a button. Itâs almost impressive.
Anyway, no fix has worked, including the one proposed by staff here. So I figured Iâd vindicate you a little, and show the staff here a picture of EXACTLY what is going on, because I was lucky enough to have a video to compare from the before.
As you can see from the picture - first image is realtime lighting working as intended. If you press Generate lighting, you will never ever ever go back to that. Its gone forever. Instead, if you use realtime lighting, you will have broken lighting and it is not possible to revert. The only way is to return to a previous version before you click the button.
HEED MY WARNING:
Never EVER click Generate Lighting.
Unity, this HAS to be fixed. Seriously.
Hey. Iâm sorry to hear youâve had such a poor experience with our tools 
Based on your screenshots, hereâs my guess as to what happened:
- On the first screenshot, it looks like you have some baked environment lighting bleeding into the interior through the walls. Even if you never Generated Lighting for the scene before, this would be the case, since the default scene template comes with some environment lighting data pre-generated.
- On the second screenshot, you Generated Lighting for the scene. Contribution from the skybox is now stored in lightmaps or light probes, and is occluded by the walls, so the color appears to change. âBakedâ and âMixedâ mode lights also stop acting as realtime lights, which might explain the shadows disappearing.
- On the third screenshot, you cleared the lighting, which also clears baked environment lighting. Thus there is no longer any contribution from the skybox whatsoever.
My guess may be wrong, but if I am correct, and you want to go back to the appearance of screenshot 1, the fix should looking something like this:
- Find every Light in your scene, ensure that each Light is set to âRealtimeâ Mode in the inspector.
- Open the Lighting Window, in the Scene tab, disable the âBaked Global Illuminationâ toggle.
- Press the Generate Lighting button.
Those steps should effectively re-generate only the environment lighting, and leave every light as realtime. Let me know if this helps.
It is what it is, I already went through my 5 stages of grief, Iâm rebuilding now. I can do it more efficiently from what I learned building it this time, and my scripts and objects are all fine of course.
I did test by starting a new project, setting up my sun, shaders, putting in the same objects and checking and it did have the desired results and the same lighting from the first screenshot.
Doing what you suggested, though it was mostly going through the motions because I had already done all that (lights are all set to realtime, baked global illumination was disabled, i had triple checked everything) yielded no results unfortunately. That just gets the results of the second screenshot.
So, Iâm not sure what goes on under the hood with lighting, but whatever it is BEFORE the Generate Lighting button is ever pressed is my desired lighting (which I got with a fresh project).
So, unless Iâm an extreme outlier (as well as the two other people in thread): if you use only realtime lighting, pressing Generate Lighting once will change your lighting permanently and its impossible to go back without reverting to an old backup. Whether this is intended or not I donât know, but I assure you itâs the case, at least for me. And like I said, I spent 18+ hours trying to fix it doing every possible fix under the sun and searching forums far and wide, so itâs not for lack of trying.
And itâs not really a problem with your tools - itâs my problem haphazardly clicking buttons that can have dire consequences without a recent backup. Lessons learned, now I go agane
I baked lighting as a test and wanted to revert to realtime lighting.
Switched my only scene light back to realtime, and in the baking window I turned off baked lighting and turned on realtime lighting.
It gets about halfway done and then just hangs. This is beyond infuriating. No errors or anything.
When I create a unity scene, realtime lighting just works. Why do I have to sit here baking realtime lights for 3 hours just to get it working again?
The worst part is that it pegs all 16 of my cores at 100% during this whole process. Iâm pretty sure its not even doing anything most of the time.
Edit: Another wonderful thing I just noticed. I cleared my GI cache before realtime baking, and now it hasnât even completed and its filled the cache with 7gb of data. Wtf is going on? Does this stuff even get tested before it enters production?
Looking at your screenshot, it looks like you have Enlighten Realtime GI enabled. Thatâs what the âRealtime Global Illuminationâ toggle in the Lighting Window does. Enlighten has a precompute step that can get very expensive for larger scenes. Your screenshot is showing that precompute step running.
Did you actually intend to use Enlighten Realtime GI? To be clear, this is not what we typically mean when we say ârealtime lightingâ. Enlighten produces indirect (bounced) light. If you only want traditional (direct) realtime lighting, you can disable the toggle.
If you did intend to use Enlighten, the next step to troubleshoot would be to check the editor log for anything suspicious. If you are using URP, you may also want to take a look at Surface Cache GI instead.