Opening up Enhanced Atmospherics to third-party developers

[BiologicalNanobot]

Hi,

Do you have plans to give third-party developers more control on Enhanced Atmospherics? Especially those two features would be really helpful:

Ability to "author" clouds with an API for custom weather maps, which would support regional / local cloud type, coverage, height and precipitation. It can be injected to the simulator using an RGBA texture. Especially for practicing predictive/reactive windshear, an accurate weather radar is extremely important and such an API would allow third-party weather engines like Active Sky to match cloud depiction with what weather radar displays, which was possible with legacy 2D clouds. Also, currently clouds look extremely repetitive at high coverages as there is little to no local height variation, resulting noise to be sampled the same way again and again. An API for authoring would fix this issue too, as third-party weather engines can inject a lot more local height variation. I know that trueSKY allows weather maps, so it should be possible.

Ability to control scattering and absorbtion parameters, which would allow slightly different sky in different parts of the world. Especially ozone content have a really significant effect on sky colors, and it is the reason why sunsets/sunrises look rather purple in some parts of the world and yellow in other parts of the world. In Prepar3D everywhere looks yellow, which is unrealistic for some parts of the world. A third-party add-on would be able to dynamically control sky colors based on location.

I believe these two features would make Prepar3D a much more realistic simulation environment and would love to see them implemented in next Prepar3D versions.

Have a nice day!

[shermank]

I agree, excellent suggestion.

Sherm

[sincedric]

Agreed, it would make customization much easier and could cater for simmers of different taste

[Sky_King]

Great suggestion. I wonder if there are some licensing issues related to that?

[sincedric]

I have been using EA for a week or two, and it could look quite nice. However, there are just strange things here and there.

1. Dark cockpits (especially for cockpits with PBR textures)
2. Weird cloud texture color with volumetric clouds turned off, especially during sunset/sunrise
3. Sun being cut-off by a fake horizon higher than the actual horizon during sunrise (and possibly sunset)
4. Overly strong ground haze and there are no options to change it
5. Bright nights and the moon is quite bright, almost like a sun at night

I'm sure there are a lot more issues. I find EA acceptable only during daylight hours. Any time other than that it would look a bit strange. I hope someone come up with ways to change how EA look. It'd be a game changer.

[BiologicalNanobot]

Great suggestion. I wonder if there are some licensing issues related to that?

I have used trueSKY SDK and I don't think there are any licensing issues with that. All of those options are exposed in trueSKY SDK, so Lockheed Martin freely can expose them to us developers. Variables at https://docs.simul.co/tutorials/sky/variables.html alone are more than enough to have full control over sky. Rayleigh scattering, Mie scattering & extinction along with Ozone extinction coefficients are main things that determine sky colors.

[BiologicalNanobot]

I have been using EA for a week or two, and it could look quite nice. However, there are just strange things here and there.

1. Dark cockpits (especially for cockpits with PBR textures)
2. Weird cloud texture color with volumetric clouds turned off, especially during sunset/sunrise
3. Sun being cut-off by a fake horizon higher than the actual horizon during sunrise (and possibly sunset)
4. Overly strong ground haze and there are no options to change it
5. Bright nights and the moon is quite bright, almost like a sun at night

I'm sure there are a lot more issues. I find EA acceptable only during daylight hours. Any time other than that it would look a bit strange. I hope someone come up with ways to change how EA look. It'd be a game changer.

A few clarifications on the subject:

1. Dark cockpits issue is not caused by Enhanced Atmospherics, it is caused by HDR. As sky and cloud lighting calculations involve brightness values outside SDR, HDR is forced on with Enhanced Atmospherics. It should be technically possible to use Enhanced Atmospherics without rendering entire scene with HDR, though - trueSKY sky and clouds are nothing more than a post-processing effect, so they could be separately tonemapped into SDR and then blended with rest of the SDR scene, but I don't know if this could work in Prepar3D.

2. Agree, "legacy" clouds have too much blue during sunset/sunrise, they should reduce ambient color contribution.

3. This is also an issue with using Enhanced Atmospherics without volumetric clouds, I believe this is caused by the way Prepar3D blends "legacy" volumetric fog with sky.

4. I would say this is accurate, Rayleigh scattering is quite strong at times in real life. But indeed it depends on weather conditions and giving third-party developers control over scattering and extinction coefficients would fix that issue too.