SSAO bug: blue glow especially on pine trees in Kaer Morhen

[fitzroy_doll]

There is an awful blue glow around some objects, especially vegetation such as trees in Kaer Morhen. This occurs when any of the following are true:

-Ray Tracing is enabled (sub-settings make no difference, though Ray Traced Reflections look bad and add some bright blue shadows)
-SSAO is enabled and set to high or low
-HBAO+ is enabled and set to high

The only solution is to set SSAO to HBAO+ and screen space reflections to low. Then it all looks great.

I can't believe the game could have shipped this way, as it looks terrible. The only thing I can think is that there is some problem with the game's implementation of SSAO and newer graphics cards. I am using a 5060 Ti with 581.15 drivers.

I have attached a report from another user on Reddit, along with his screenshot. This is the same issue I am experiencing. No mod or config tweak I have found fixes it.

 

[SigilFey]

Are you using DLSS, FSR, XeSS, etc?

That sort of thing can happen due to the built in anti-aliasing of the various supersampling techs. It's can sometimes be mitigated by adjusting the sharpening. Ambient occlusion will create more color gradation in the darker corners and seams, and higher reflections mean more detailed specular maps, simultaneously creating more color gradation on "shiny" surfaces. Crush all those values for extra darkness and extra light reflections together with something like DLSS, and the results might get a little wild.

If that's occurring while using a true resolution...yikes. Does it happen a lot, or is it only certain spots under specific lighting?

Separate question:
Are you toggling between SSAO and HBAO+...or are you saying they're both on? They are exclusive: a game will use one or the other. If you have an Nvidia card, HBAO is their in-house ambient occlusion tech, so that will usually give better image quality. SSAO is a different option, more widely available to more GPUs. (Which one looks better depends on the game, the GPU, and preference.)

If both are showing as active at the same time, that would be quite a strange situation.

 

[fitzroy_doll]

Thanks very much for your reply.

To clarify, yes, this occurs when toggling between SSAO and HBAO+ (but oddly not with HBAO+ and the screen space reflections set to low). As you say, it's not possible to have SSAO and HBAO at the same time, but that whole section of the menu is called Screen Space Ambient Occlusion, hence the confusion: you can set SSAO to SSAO or HBAO+ for example.

Turning off DLSS makes sense but did not fix the issue.

From further testing the blue branches bug seems to appear when in a shaded environment such as the canyon behind the forktail cave in KM. Whatever the game is trying to do with light in such a setting is coming out as a pure white or blue fringe. When the sun goes around and direct light falls on these areas then the effect disappears and the scene looks normal.

The workaround then is to simply turn off ray tracing in Kaer Morhen, and anywhere else the bug occurs.

Here are some examples:

Image below: RT on, DLSS off (DLSS on looks the same but less jagged), note white trees and grass:

Image below: RT off, HBAO+ high screen space reflections. SSAO also looks about like this.

Image below: RT off, HBAO+ low screen space reflections:

Image below: Here is an additional view of the insane blue shadows that occur a bit later in the day in this spot (RT on, DLSS on):

 

[SigilFey]

Thanks very much for your reply.

To clarify, yes, this occurs when toggling between SSAO and HBAO+ (but oddly not with HBAO+ and the screen space reflections set to low). As you say, it's not possible to have SSAO and HBAO at the same time, but that whole section of the menu is called Screen Space Ambient Occlusion, hence the confusion: you can set SSAO to SSAO or HBAO+ for example.

Turning off DLSS makes sense but did not fix the issue.

From further testing the blue branches bug seems to appear when in a shaded environment such as the canyon behind the forktail cave in KM. Whatever the game is trying to do with light in such a setting is coming out as a pure white or blue fringe. When the sun goes around and direct light falls on these areas then the effect disappears and the scene looks normal.

The workaround then is to simply turn off ray tracing in Kaer Morhen, and anywhere else the bug occurs.

Here are some examples:

Image below: RT on, DLSS off (DLSS on looks the same but less jagged), note white trees and grass:

View attachment 11425253

Image below: RT off, HBAO+ high screen space reflections. SSAO also looks about like this.

View attachment 11425244

Image below: RT off, HBAO+ low screen space reflections:

View attachment 11425238

Image below: Here is an additional view of the insane blue shadows that occur a bit later in the day in this spot (RT on, DLSS on):

View attachment 11425271

Ah -- the lower detail pics definitely look more "photo realistic" in that lighting because the additional reflective detail is not there. I think this is actually just the engine being the engine. TW3 loves its specular maps.

The first image in that post is exactly what the game has always looked like. That's just the way that REDengine handles reflections on "twigs, nooks, and grains of sand" at the highest detail settings. Sharpening set at just the right level will make it less apparent, but it will never go away completely. (The image in your OP is a bit crazy, but that's likely just a very specific lighting situation in that spot.) Probably the only way to get rid of it completely will be to scale down the graphics to the use lower settings, which will not attempt to draw all that extra lighting and shader detail. This will cost a good amount of depth and richness of color in other scenes, however.

But all of the images in your second set look exactly like what I see on my end, and always have. TW3 is not a modern game using the latest graphical tech. When it came out, ray-tracing was not available on gaming GPUs. Ambient occlusion was a fairly new addition to rendering engines. DLSS and supersampling didn't exist yet. The engine was built to do some impressive things with what was available at the time, but it's a proprietary engine originally created in the early 2000s. What you're seeing...even with all the Next-Gen stuff they managed to work into it...is its age.

 

[fitzroy_doll]

>But all of the images in your second set look exactly like what I see on my end, and always have.

This is good to know! I suppose I was unlucky to upgrade my gpu hardware just as I arrived at KM, but at least now I can stop looking for a solution. Agreed about the age of the engine, and no wonder the next game will be in UE.

Thanks again!

 

[SigilFey]

>But all of the images in your second set look exactly like what I see on my end, and always have.

This is good to know! I suppose I was unlucky to upgrade my gpu hardware just as I arrived at KM, but at least now I can stop looking for a solution. Agreed about the age of the engine, and no wonder the next game will be in UE.

Thanks again!

Absolutely!

Also, if the specular highlights bug you, you should still be able to use HBAO+ for the ambient occlusion. All that will do is darken recesses to make things pop more. The reflections quality is the part that's making the tree branches "glow" like that.

You should have seen it at release. Geralt's default armor, in the right lighting, could look like a disco ball because of every link of the mail wanting to reflect light.