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Some interesting ALS artifacts at high altitude

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Some interesting ALS artifacts at high altitude

Postby islandmonkey » Sun Jan 25, 2015 2:16 pm

Image

Take a look at this. It's almost like ALS's skydome has got itself a little confused about the time, causing it to paint this out of position colour range on the skydome. If we switch the time to 17:00 local, this artefact blends in:
Image

This also occurs at night time in the opposite way:
Image

I was travelling:
At 1151kts GS
On 54700ft
200-400nm south-east of St. Petersburg, heading in a south-west direction.

Interestingly, the artefact disapeared after switching back to an outside view after being in the cockpit view for ~5 minutes.

See my PC information by clicking on my username.
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Re: Some interesting ALS artifacts at high altitude

Postby Thorsten » Sun Jan 25, 2015 3:58 pm

What weather system are you using?

(Some of them look like having a very low aloft visibility at 54.000 ft (which is unrealistic, as the air at that altitude is very clean) which Basic Weather tends to do, but AW has an altitude dependence of aloft visibility which prevents that)

I've seen something like the first one once - I believe it's a rounding error - there's plenty of large numbers entering the skydome and we only have floating point accuracy. They're really architecture specific and I don't see this on my graphics card at all.
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Re: Some interesting ALS artifacts at high altitude

Postby islandmonkey » Sun Jan 25, 2015 4:13 pm

Well I did realise at the end of the flight that I was on basic weather and thought that might be the cause of my problem (I changed to 3.5 in the past few days, throwing out autosave of settings etc).

Although I didn't screenshot this, this may have also been a cause of a problem I had yesterday while flying at 8000ft with basic weather on. I noticed that the dark sky refused to fill the horizon (this was at 18:00 local time over Belgium) and simply skirted above it -- so the sky above was black and everything in front of me and below me was still light. I segfaulted a couple of minutes later, restarted over at Frankfurt (same local time) and it was dark everywhere.
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Re: Some interesting ALS artifacts at high altitude

Postby islandmonkey » Sat Feb 07, 2015 12:03 pm

Hmm, this happened again, this time with advanced weather on, at about the same alt as before, now in between Hawaii and Guam, somewhere around E180N014 -- see flight plan at viewtopic.php?f=15&t=25151&start=195#p231278 (disregard the given altitude and speed on that plan):

Image
Image
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Re: Some interesting ALS artifacts at high altitude

Postby Thorsten » Sat Feb 07, 2015 1:06 pm

Try to reproduce them with the ufo and control the conditions which cause them (varying time, weather, visibility,...) I won't do two hour Concorde flights in the vague hope to see anything :-), and I don't get any obvious issues myself. So to debug this, you need to come up with a test case you can produce reliably and quickly.
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