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Inaccuracy with BP_SunPosition in southern USA

Having lived at this lattitude most of my life I can say that there is never a month here that it does not get completely dark at night. Some months it is not until later, but never is the sky still lit at 23:00 In general there is too much variation in months in the BP_SunPosition for this lattitude - it looks like it was created for Europe or at least northern USA and does not properly take into account that at middle lattitudes there is less difference between months and no months where it is always light or dark.

using the 4.21.1 demo scene, setting for the Blueprint needed to reproduce are in the screenshot.

Correct. For this release, we focused on the calculation of the Sun azimuth and altitude and not the complete visual perception of the Sun and Sky system where correct illuminance is calculated. We will have to work on that part separately. Right now, its a position controller and not a full environmental simulator.

OK thanks, good to know. The issue is that the horizon is still “orange” at 23:00 but should be black, as it is when the month is January - I guess this is what you mean?

Also on the page https://docs.unrealengine.com/en-us/Engine/Rendering/LightingAndShadows/SunPositioner
the descriptions of latitude and longitude are reversed.

Yes, the calculation of an accurate sky model requires some work. There are models out there that usually do a pretty good job and we are looking at them. We don’t have formal delivery dates but we know we need to look at this problem for the architectural market.

Here is an example of work that was done elsewhere that can be fairly inspiring :slight_smile: https://media.contentapi.ea.com/content/dam/eacom/frostbite/files/s2016-pbs-frostbite-sky-clouds-new.pdf

Ok great! I’m glad to hear its a known issue and plans to be addressed. Its not an urgent feature for us, but one we will take advantage of as soon as it ready. For now are just setting our sun positioning to a single month rather than letting our users select the month, we may experiment with by season and see if we can pick days that are close enough at this location.

In the meantime, to control those hazy colors when the sun is under the horizon, you can select the BP_SkySphere in your level and play with its settings in the Details panel to alter the aesthetics. If you uncheck the Colors Determined by Sun Position, then you can freely set the Zenith Color, Horizon Color, etc to make the colors look the way you want.

here’s a quick night sky without the orange haze