1 hour ago, blingthinger said:

he improvement to FPS a

But I didn t see that at all.

And neither did I. In fact, a small degradation in frame rates, but a smoother overall experience. Apart, that is, from a very significant drop in performance on approach to an uncomplicated airport (NZWN), where fps fell from 35/40 to 13. Never seen before, and indicative of a bug.

I will wait for v12.07

11 hours ago, Gulfstream said:

Maybe it's just the software engineer in me but looking a patch notes compared to what people are discussing makes no sense.

Either the patch notes aren't inclusive of what went out in the patch, or what everyone is reporting is just the placebo effect.

For clouds, the only two things I see that should be affected are the pyramid clouds and clouds during the replay.

• XPD-13975 – Pyramid clouds appearing randomly
• XPD-14034 – Changing weather/Cloud conditions not displayed correctly in replay mode

As to shimmering, FPS, etc.  I don't see anything in the patch notes that has anything to do with this.

I'm used to this though.  30+ years of flight simulation leaves you jaded ... I'm probably just getting cranky in my old age.  I've just seen too many "seems like I'm getting 1-5 more FPS / FPS is worse" or "things are blurry / things are much sharper!" posts after every update.

This isn't a jab at Laminar, those patch notes are solid and it looks like it addressed numerous customer-facing problems.

Just not the ones people are discussing in this thread.

It is rather confusing but the release notes only include the features marked as finished and not the ones are under continuous work. Therefore a lot of the improvements in the beta are not mentioned.

On the performance side, while it won't necessarily translate into FPS improvements, VRAM management should be significantly better.

On the visuals side, there are several improvements. In terms of the atmosphere, the default atmospheric scattering and absorption coefficients (which were from Sebastien Hillaire's paper) are replaced with much more accurate ones which take the entire visual spectrum into account. As a result of that, the sunsets & sunrises will have a blue look rather than a purple look, like in real life. Other than that, the aerial perspective / haze is now visible in close distance and low altitude. Lastly, you will no longer see aerial perspective artifacts at the DSF border, which is towards the horizon. In terms of clouds, cirrus clouds are now accurately depicted and the default cloud noise is much better. Additionally, the temporal reprojection should work significantly better now.

I also see some drops in FPS, but I can't reproduce them or link them to some specific plugin or aircraft. At one point rain alone would cause a 10 FPS drop.

3 hours ago, Biology said:

In terms of the atmosphere, the default atmospheric scattering and absorption coefficients (which were from Sebastien Hillaire's paper) are replaced with much more accurate ones which take the entire visual spectrum into account. As a result of that, the sunsets & sunrises will have a blue look rather than a purple look, like in real life.

YES! I initially missed that, but now the blue hour is there, in all of its beauty! That should make dusk/twilight flight much more realistic. One of the aspects that I always found immersion breaking in sims, were the unrealistically reddish twilights.

I could be wrong, so maybe I will stand corrected, but I think other sims (those that model atmospheric scattering, not the old ones that use skycolor textures) are not modeling that.

 

Edited July 25, 20232 yr by Murmur

1 hour ago, Murmur said:

YES! I initially missed that, but now the blue hour is there, in all of its beauty! That should make dusk/twilight flight much more realistic. One of the aspects that I always found immersion breaking in sims, were the unrealistically reddish twilights.

I could be wrong, so maybe I will stand corrected, but I think other sims (those that model atmospheric scattering, not the old ones that use skycolor textures) are not modeling that.

 

TL;DR: You are mostly correct, but the issue is a bit more complicated than other simulators not modelling it. Basically almost all of atmospheric scattering implementations in any flight simulator (both first-party and third-party), even my own Enhanced Skyscapes, with the exception of xEnviro and FlightGear are based on either Sebastien Hillaire's or Eric Bruneton's papers which have a mistake on their coefficients, resulting in wrong colors during sunset and sunrise.

For those who are interested, here is the long story:

In order to model atmospheric scattering, scattering and absorption coefficients are used to describe the medium in which the light scatters and gets absorbed. As both scattering and absorption is wavelength dependent, both scattering and absorption coefficients are defined for all wavelengths in the visual spectrum. However, in most games, including X-Plane 12, rendering is done in RGB (more specifically sRGB color space), which poses an issue - somehow the coefficients for all wavelengths need to be converted into coefficients for just red, green and blue components. As a solution, a paper way back in early 2000s decided to simply arbitrarily pick 3 wavelengths for the red, green and blue components - 680 nm, 550 nm and 440 nm respectively. Both Hillaire's and Bruneton's papers used the same wavelengths without any modification, and this is where the issue starts. The early 2000s paper I mentioned only modelled Rayleigh and Mie scattering caused by the major constituents of the air (oxygen, nitrogen and aerosols), and their arbitrary wavelength choice was likely tuned for their model. However, there is one more constituent of the atmosphere which has a significant effect in the sky colors during sunset and sunrise - it's ozone. Ozone absorbs a lot of red and green light, and it is what causes the blue hour. In order to simulate blue hour, both Hillaire's and Bruneton's papers introduced ozone absorption into their models. However as they didn't change the wavelengths from the early 2000s paper, which wasn't tuned for ozone, the results were inaccurate, more specifically, the sunsets and sunrises looked too purple. And this brings us to the main issue - there isn't a single wavelength for red, green and blue - 680 nm is red, but so is 650 nm, 550 nm is green, but so is 580 nm, 440 nm is blue, but so is 460 nm. So a lot of tuning is required to pick the "right" wavelengths for a given atmosphere model. However, there is an alternative solution, which is what was used in X-Plane 12:

What if instead of picking a single wavelength for red, green and blue, we managed to find a way to calculate the contribution of all wavelengths? Turns out this is possible, by using CIE 1931 XYZ color matching functions. By converting the CIE 1931 XYZ color matching functions to sRGB "color matching functions" using the transformation matrix from the official sRGB specification, what you get is sRGB color space representations of all wavelenghts, in a way showing the contribution of all wavelengths into red, green and blue. By taking a weighted average of the scattering and absorption coefficients where the weights are set to the sRGB "color matching functions", it is possible to consider the contribution of all wavelengths for red, green and blue, resulting in much more accurate coefficients. You can try my open source Python implementation here if you want to learn more about how it works, it includes visualizations and helpful comments as well: https://github.com/FarukEroglu2048/ARPC

Edited July 25, 20232 yr by Biology

6 minutes ago, Biology said:

For those who are interested, here is the long story:

Congratulations! That was an incredible work. I've been missing my beloved blue hour for years, can't say how happy I am to finally have it. Looking forward to even more future improvements in X-Plane lighting. 😁

17 hours ago, mjrhealth said:

But I didn t see that at all.

Maybe it's a VR thing then, because that bit is significantly different on my end. I gotta do some proper FPS tests too, which sadly isn't a thing in VR yet.

23 hours ago, mjrhealth said:

But I didn t see that at all.

A quick and dirty 'grain of salt' test. Sliders maxed except AA (4x), 1080p. Clean demo installs. No AI. i7 12700, 7900xt.

Pointed default 738 towards the KPDX terminal, at night, with some clouds and let FPS settle a bit. In my experience, that's where I'd often see some FPS jitter. Is there a way to get these values to print during one of the FPS tests? I'll try again later, but haven't ever been able to get Data.txt to show up when the CLI flag is set to fps test.

Likely some placebo going on in win10 which is where I was 'seeing' improvement, but ....dunno. The drops in win10/12.05 are notable and there's certainly some variation in the airport vehicle traffic. Might need to let it settle longer too.

VR improvement is not placebo though and the openxr stuff isn't even in yet. VR/linux/monado can't come soon enough.

Yaxis is FPS (for those who don't recognize that gibberish label).

Edited July 26, 20232 yr by blingthinger

On 7/25/2023 at 12:02 AM, Sethos said:

Under certain conditions, the new clouds really look nice,

I'll make sure to only fly under those "certain conditions" then. where do I set that "certain conditions" option?

14 hours ago, Biology said:

TL;DR: You are mostly correct, but the issue is a bit more complicated than other simulators not modelling it. Basically almost all of atmospheric scattering implementations in any flight simulator (both first-party and third-party), even my own Enhanced Skyscapes, with the exception of xEnviro and FlightGear are based on either Sebastien Hillaire's or Eric Bruneton's papers which have a mistake on their coefficients, resulting in wrong colors during sunset and sunrise.

For those who are interested, here is the long story:

In order to model atmospheric scattering, scattering and absorption coefficients are used to describe the medium in which the light scatters and gets absorbed. As both scattering and absorption is wavelength dependent, both scattering and absorption coefficients are defined for all wavelengths in the visual spectrum. However, in most games, including X-Plane 12, rendering is done in RGB (more specifically sRGB color space), which poses an issue - somehow the coefficients for all wavelengths need to be converted into coefficients for just red, green and blue components. As a solution, a paper way back in early 2000s decided to simply arbitrarily pick 3 wavelengths for the red, green and blue components - 680 nm, 550 nm and 440 nm respectively. Both Hillaire's and Bruneton's papers used the same wavelengths without any modification, and this is where the issue starts. The early 2000s paper I mentioned only modelled Rayleigh and Mie scattering caused by the major constituents of the air (oxygen, nitrogen and aerosols), and their arbitrary wavelength choice was likely tuned for their model. However, there is one more constituent of the atmosphere which has a significant effect in the sky colors during sunset and sunrise - it's ozone. Ozone absorbs a lot of red and green light, and it is what causes the blue hour. In order to simulate blue hour, both Hillaire's and Bruneton's papers introduced ozone absorption into their models. However as they didn't change the wavelengths from the early 2000s paper, which wasn't tuned for ozone, the results were inaccurate, more specifically, the sunsets and sunrises looked too purple. And this brings us to the main issue - there isn't a single wavelength for red, green and blue - 680 nm is red, but so is 650 nm, 550 nm is green, but so is 580 nm, 440 nm is blue, but so is 460 nm. So a lot of tuning is required to pick the "right" wavelengths for a given atmosphere model. However, there is an alternative solution, which is what was used in X-Plane 12:

What if instead of picking a single wavelength for red, green and blue, we managed to find a way to calculate the contribution of all wavelengths? Turns out this is possible, by using CIE 1931 XYZ color matching functions. By converting the CIE 1931 XYZ color matching functions to sRGB "color matching functions" using the transformation matrix from the official sRGB specification, what you get is sRGB color space representations of all wavelenghts, in a way showing the contribution of all wavelengths into red, green and blue. By taking a weighted average of the scattering and absorption coefficients where the weights are set to the sRGB "color matching functions", it is possible to consider the contribution of all wavelengths for red, green and blue, resulting in much more accurate coefficients. You can try my open source Python implementation here if you want to learn more about how it works, it includes visualizations and helpful comments as well: https://github.com/FarukEroglu2048/ARPC

I'm amazed by your work and your knowledge ! Thanks a lot for your contribution !

I dabbled a bit with the scattering shader some years ago, and I always thought that only taking the rgb components into account was a very limiting simplification. I'm amazed that you could take the whole spectrum into account.

From your description, I'm not sure I understand if you calculate the contributions of the whole spectrum in real time, or if it's just used to find a more correct set of 3 coefficients for rgb. Could you please enlighten me on this point?

Edited July 26, 20232 yr by Pascal_LSGC

1 hour ago, turbomax said:

I'll make sure to only fly under those "certain conditions" then. where do I set that "certain conditions" option?

flight-> show IOS (shortcut key "i") click + then the pencil next to weather, set it, then click change weather.

e.g. VFR Broken

You or a loved one can also do it from the free instructor iPad app from the apple store

Edited July 26, 20232 yr by mSparks

1 hour ago, mSparks said:

from the free instructor iPad app from the apple store

sorry, no apples in this household.

anyway, I can't believe it: just had the best xplane flight in centuries, St.Elmos fire around my airplane contours gone, frankenclouds at 6:00 p.m. gone, anti aliasing issues? gone. is this still x-plane or did I run another simulator inadvertently? had a fantastic flight in the default C172 at 7:30 p.m. with default real world weather from Marthas Vineyard in light rain to Nantucket at 13.500 ft in VR. second to none! I can't believe this is x-plane, I am not yoking. honestly. and this from someone who is spoilt by the best scenery VFR simulator with the best avionics package. 😊

1 hour ago, turbomax said:

sorry, no apples in this household.

anyway, I can't believe it: just had the best xplane flight in centuries, St.Elmos fire around my airplane contours gone, frankenclouds at 6:00 p.m. gone, anti aliasing issues? gone. is this still x-plane or did I run another simulator inadvertently? had a fantastic flight in the default C172 at 7:30 p.m. with default real world weather from Marthas Vineyard in light rain to Nantucket at 13.500 ft in VR. second to none! I can't believe this is x-plane, I am not yoking. honestly. and this from someone who is spoilt by the best scenery VFR simulator with the best avionics package. 😊

Is this still turbomax or did I read somebody elses post inadvertently?  This post is second to none! I can't believe this is turbomax, I'm not joking! Honestly, this from someone who is spoilt by the best XP posters!

😁

Edited July 26, 20232 yr by MrBitstFlyer