OK here it is. I think that:
1) The sky brightness fluctuations are reduced a bit before entering the tunnel.
2) Slightly earlier exposure reduction at end of tunnel.
I'm not sure what you mean. Are you referring to a difference between the two versions?
They both have the same rate of adjustment.
The new one uses centre-weighted metering, which has two advantages:
1) Exposure based more on what you are actually looking at, instead of peripheral vision.
2) More stable because peripheral parts often have large bright or dark areas that have a bad effect on exposure.
I wonder how it would look with a slower rate of adjustment. Now it seems a bit too quick especially around 0:03-0:04 during the transition into the shadow before the tunnel where it changes in just like 10 frames or so. I know it's never going to be a perfect representation of human vision in SDR mode anyway, but I feel like the changes in exposure could be a bit smoother/longer.
It looks better already with the center weighting, but I'm also curious about slightly slower transitions as Flame mentioned.
Also, I'm now wondering about triple screen (or other multiple screen setups): is the center weighting stretched over all screens, or just the center screen?
Looks cool, I wonder if there will be an auto-exposure level adjustment in the settings, for example with a slider from 0 to 100? Or will it be an unchangeable value?
Transition looks nice.
My only thought is that brightness in the tunnel is little bit too high.
I'm worried how it behave while driving in the night if if doesn't feel like driving during the day because of exposition change. Night is night and there should be black around.
It is the same problem like with photo camera where center weight average metering fails sometimes (black cat over white wall will be underexposed for example) and you need to apply EV correction manually.
I think the tunnel lighting is quite well balanced, compared with the street lighting. Eric has set the lighting values by observation, we haven't gone so detailed as to set watts or lumens per light. But you can judge for yourself in this similar video done in the night.
EDIT: This video time is 03:14 on 4 May so the sky is not pitch dark.
Exposure changes look quite fantastic now, so as illuminated displays.
I notice that color tone is slightly towards netral (cool) while previous it was more towards warmer tint. I know that this is during night time, but it's the same tunnel with the same light sources. Has anything else been changed with lighting?
Thanks for the night version, really nice too!
You mentioned the sky not being pitch black because of the date, and while I'm not sure of the difference between France and the UK, I was still expecting something darker, but more to the point - I think there's a bit too much ambient light outside, I believe the buildings and even the road should look much darker even with the sky's current brightness and street lights.
In the tunnel itself, this may be more subjective of an opinion, but in my experience, French tunnels at least are much darker than this (if you look at the following picture, you should adjust exposure to at least -3 to get something that's more true to life (except the image itself has no usable dynamic range at that exposure value)):
With that said, it will probably turn out to be necessary to expose user settings for auto-exposure.
Our system is really not set up for shadow maps from street lights, the street lights are really just a source for ambient lighting.
Maybe interesting to know that there are two exposures going on.
Other than the image-based exposure that I have been talking about, there is also a calculation based on sun height and sky brightness, which can be used to produce a roughly suitable exposure level in an SDR mode that I am currently still supporting, that doesn't have bloom or analyse the image for exposure. That gives quite reasonable results in the day and might be a helpful option for people with a low powered GPU. That calculation is very simple and done every frame even in the HDR mode (HDR is not for HDR monitors, it's just that internally we process the image using a high dynamic range).
Anyway why I am talking about that, currently that is the value that is used to set the dashboard brightness. Without that, the dashboards were EXTREMELY bright in the night, so it was a quick fix at some point in the past. Anyway as discussed earlier, it's not working well and I might do something based on getting a lighting value from your car's environment map, to simulate a light sensor, or I may take a simpler approach (for now) and just set a direct value, so the dash appears just as it does in current public LFS. I am making decisions to get to release without getting hung up on details. That would be awaiting the better dashboard support where we could allow parts of the dashboard to be illuminated by the environment.
White balance is also based on the time of day rather than the current image. Instead of trying to analyse the image for white balance, it's simpler just to take some good values for day and night. If I used the day white balance in the night, everything would look too yellow, as we are using realistic values for the street lights.
Well here in England, we are quite far North so in May we have short nights and there is a bit of twilight at 3am. I could do a pitch black one but don't think it's really worth it at the moment, though I can make these videos quite quickly.
By the way, I have noticed your other posts. I have tried an ACES filmic shader, might show some comparison screenshots at some point, though personally I don't like it as reality doesn't look like a film, if you see what mean.
I haven't researched enough about AgX, the ones I found did look complicated and all the example shots I saw on the internet just looked like a purple version of the image, so I wasn't sold on the idea. But I'll probably follow your link to see if the simpler version you linked to is of reasonable complexity. At the moment I am using a simple Reinhard shader to reduce the sky whiting out.
I haven't looked into tonemappers in-depth, just enough to know the differences as a user, but I don't remember AgX being purple (it tends to look like uncorrected log film out of the box, so really desaturated images, and you should then color correct and adjust contrast and such) - I can say however that a good, properly adjusted, AgX tonemapped image can look much better than other tonemappers as it basically removes hue-shift for high-saturation, high-illumination scenarios and is smoother overall in its color range.
But I will happily take the current implementation for a first release, like you're planning to do for the dashboard illumination, as it already looks much nicer than the current public version
Here is Godot's implementation for reference (Vulkan/OpenGL based): https://github.com/godotengine/godot/pull/87260
There are also a few more pull requests related to AgX adjustments made later.
You can also find some nice comparisons made in Blender, typically between sRGB, Filmic and AgX.
Oh, yeah, those example images do look like the AgX colors are off, it kind of looks like a white balance issue, as even pure white appears pink-orange in the red/green/blue/yellow lights example. Certainly not the usual kind of results other comparisons show, from what I've seen.