The weather in XP12...

[jcomm 5,920]

Maybe some of you around here have privileged access to LR, and be able to remind them about some insight on their weather modelling for XP12, for the upcoming presentation at Sim Conference...

I would like to know about which sources will be used outside USA, and what will the granularity in terms of altitude be.

Sometime ago I suggested here the implementation of non ISA lapse rates for pressure levels. This may already be taken into consideration, but I would love to see it mentioned.

Evidence of Sun, Moon ephemeris, as well as proper daylight according to location/date and perpetual calendar would be great too !

Edited September 12, 2021 by jcomm

[Paraffin 2,197]

5 hours ago, jcomm said:

Evidence of Sun, Moon ephemeris, as well as proper daylight according to location/date and perpetual calendar would be great too !

This should be prioritized, not just for accuracy but also for marketing screen shots. 

One of the reasons some of the MSFS screen shots look so spectacular isn't just the world rendering, but the fact that you can pick the perfect sun angle for a shot by adjusting time of year when you're somewhere in the northern or southern latitudes.

I was so used to XP's fixed sun angle that I didn't even realize it worked that way, until I tried to make some screenshot comparisons in the early MSFS alpha test. And then I realized that XP doesn't change the sun path because there is no calendar. 

 

[Murmur 3,941]

2 hours ago, Paraffin said:

I was so used to XP's fixed sun angle that I didn't even realize it worked that way, until I tried to make some screenshot comparisons in the early MSFS alpha test. And then I realized that XP doesn't change the sun path because there is no calendar. 

But that's not correct. Both sun elevation and azimuth are depending on calendar in XP.

Sun azimuth at sunrise on 21/1 vs 21/6:

Max sun elevation on 21/1 vs 21/6:

 

Edited September 12, 2021 by Murmur

[jcomm 5,920]

Yes, as Murmur pointed out, but the big difference is that in other simulators the following works as it should, while in X-Plane it doesn't:

.) Given a date and place on Earth, the time and azimuth of the rising / setting Sun are correct;

In X-Plane there's no perpetual calendar, so, what we get just as with magnetic declination is a reference ephemeris for a given year...

.) The above should be coupled with proper lighting effects that, for instance, take the obliquity and it's effects on the atmosphere to create realistic lighting effects around the dusk and dawn hours. In some places and dates it's pitch dark in XP's Earth while in RL ( and the other sims ) you already have enough twilight to not even bother turning on your cockpit and panel lights 🙂

Then the fact that there is no perpetual calendar also impacts on the Moon and other Celestial bodies and star constellations ( afaik not even presently represented whatsoever in X-Plane ). In other sims they get pretty decently represented and, at least for me, make a whole lot of a difference...

Edited September 13, 2021 by jcomm

[Alec 370]

It seems to be X-Plane way of operation, they don't like things dynamically adapting  over the course of year. They would rather pick a time period, within the X-plane Version Lifespan, of say, 4/5 Years, and match everything realistically to that single point in time. Exactly what we discovered is done in their Magnetic Declination Tables. It used to be good enough, but nowadays I don't think this is enough, they need to step up their game and make a sim that feels alive, to better match the competition. And to do that. you can't rely on being accurate once in a year.