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Extended Environment in Cool VL Viewer 
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Joined: 2010-04-07 08:23:18
Posts: 207
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Hello Henri et al.,

I've been running the viewer with EEP enabled for some time now and always was marginally irritated that the day/night cycle seemed significantly off from what it should be. I always chalked it up to EEP not being finalized and never looked into it deeper.

Now that it is slowly spreading to a wider audience, I have started to look at it closer. It seems that the day cycle in Cool VL viewer is indeed not matching what it should be when compared with the LL viewer.

This is most apparent when looking at the Day parameters' "Apparent time of day:" values. While the ones calculated in-world using LSL and shown in the LL viewer match, the ones displayed by Cool VL are quite different (in the same spot with the same Day length and Day offset, obviousy). And we're talking serious difference, e.g. 72% (17:17) in Cool VL and 12% (3:00) in LSL and the LL viewer.

Has anyone else played with this yet and can share some insights? I am more than willing to believe it's a PEBKAC, but it really does look like a bug to me the more I tinker with this.

Any input would be much appreciated.


Regards,
Lia


2020-12-12 12:36:31
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Joined: 2009-03-17 18:42:51
Posts: 4751
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And I'm "marginally" indifferent to Extended Evironment (EE: the P was for "project", which EE is not any more, since it was released)... :P

I don't use it personally and it should be considered a mere gadget feature, seeing how badly it impacts frame rates for quite minor an "improvement" in environment rendering, not to mention most people will "second-live" with their avatar indoors 90% of the time and won't care about how pretty the sky looks...

The EE time of day was coded back when the viewer was still not able to render EE and was instead translating the EE settings into Windlight ones (which it is still doing, when the EE shaders are off), so I coded it in a way that allowed to translate EE time into Windlight time (especially for parcel environment, which had to stay compatible with other viewers, which were all Windlight ones back then)... Yes, there is a time difference between EE and Windlight, but frankly, is it that important ?
I added a feature (that other EE viewers do not even have), which allows to set your local EE (fixed) time, via the "Local environment editor" (check the "Fixed time" box and use the slider to set your custom time).

I might have a look at this "issue", (real !) time and motivation permitting, but don't hold your breath on it, for it's very low on my "to do" list !

But of course, if some other coder feels motivated enough, they could come up with their own patch (and post it in the Contributions forum)... :idea:


2020-12-12 20:24:53
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Joined: 2012-01-19 03:18:40
Posts: 148
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I don't use EE, but I've been puzzling over an issue with the "day-night cycle" ever since Cool VL Viewer became "Windlight aware", which is that the day cycle in my home regions no longer seems to correlate with the sun-position as reported by llGetSunDirection. This is a problem, because years ago I scripted environmental gadgets that rely on the height of the SL sun to determine whether it is day or night. The lanterns at my inn, for example are supposed to turn on at dusk and off at dawn, but that does not synch up with the time of day I perceive in-world unless I manually set Windlight Region Time which also sets the Use Estate Time checkbox on the Windlight Editor's Day Cycle tab.


2020-12-14 03:39:08
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Joined: 2009-03-17 18:42:51
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linyifei wrote:
I don't use EE, but I've been puzzling over an issue with the "day-night cycle" ever since Cool VL Viewer became "Windlight aware", which is that the day cycle in my home regions no longer seems to correlate with the sun-position as reported by llGetSunDirection. This is a problem, because years ago I scripted environmental gadgets that rely on the height of the SL sun to determine whether it is day or night. The lanterns at my inn, for example are supposed to turn on at dusk and off at dawn, but that does not synch up with the time of day I perceive in-world unless I manually set Windlight Region Time which also sets the Use Estate Time checkbox on the Windlight Editor's Day Cycle tab.
Well, AFAIK, there are three different times: estate, region, parcel (plus a fourth, which is the local time that applies only to you when you override all the others).

With extended environment, LL added a server-side translation so that Windlight viewers could still be fed with the parcel Windlight settings (something the Cool VL Viewer never took into account, even today: it only uses WL region time with Windlight, which is not estate or parcel time either !).
Note also that EE brought variable day length, in excess of variable time offsets, as well as variable Sun (and Moon) angles (that WL cannot account for at all), which is different from how WL works !

So, there are quite a few possible combinations, depending whether you use EE or WL, estate, region or parcel time (and Sun/Moon angles). Not sure either how the related LSL functions do work with regards to all this mess (llGetSunDirection() would be affected with parcel EE settings Sun angles, in excess of the day cycle settings, for example)...

Since I personally always use the viewer in midday setting (I even added, many years ago, a "Cool feature" option to set a fixed time at login), it never bothered me ! :lol:

Again, if someone feels like proposing a "fix", be my guest !
Note that it would likely involve quite some coding to take Windlight parcel/region settings sent by sims into account, at least in WL rendering mode, and acknowledging the fact the corresponding server-side interim code will likely be shut down by LL in a not so distant future... Not sure it is worth it at all...

Normally and currently, the viewer should properly sync with parcel time, as long as you check the "World" -> "Environment settings" -> "Use parcel environment", at least in EE rendering mode (no guarantee offered with WL rendering mode, due to variable day length, Sun and Moon angles settings that it cannot properly deal with, since EE does not even transmit a "time of day" (or Sun elevation) parameter, instead using a "blender" code with a percentage to calculate the Sun and Moon positions).

What you should retain to understand the complexity of the issue is: Windlight uses an extremely simplified model (Sun rises from East and sets down in West, Moon is at a fixed 180° opposition with the Sun), while EE uses a model where many more parameters may be modified (like if you could change the Earth rotation axis and Moon orbit around the planet, for example). Clearly, the two models are incompatible when using the most advanced features of the second one.


2020-12-14 10:10:30
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Joined: 2010-04-07 08:23:18
Posts: 207
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Hello again,
Henri Beauchamp wrote:
Normally and currently, the viewer should properly sync with parcel time, as long as you check the "World" -> "Environment settings" -> "Use parcel environment", at least in EE rendering mode [...]
Which is not the case, hence my initial post -- and originally triggered by the same observation that linyifei made: lights turning on or blinds closing during daytime etc.

So at least I do know now that there is an issue, which seemingly not just affects Extended Environment but also the Windlight translation that is happening (which I presume should be accurate for the "default" / legacy environment).

Regards,
Lia


2020-12-14 18:38:51
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Joined: 2009-03-17 18:42:51
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Amalia Illios wrote:
Hello again,
Henri Beauchamp wrote:
Normally and currently, the viewer should properly sync with parcel time, as long as you check the "World" -> "Environment settings" -> "Use parcel environment", at least in EE rendering mode [...]
Which is not the case .../...
Ouch !

It used to be the case, but some time ago I fixed an issue with clock counts going backwards in the viewer when the computer clock was adjusted (which caused all sorts of "funny" glitches, such as the "head in the ass" animations), and doing so I had to use "monotonous" clock counters (counters that never go backwards), which, depending on the OS, are not guaranteed to be referenced to the UNIX epoch (1970/01/01 00:00 UTC). I thought I plugged all the cases where it would affect the viewer, but I missed one !... LLDate::now() does not always return the right number of "seconds since epoch" as a result, which ruins environment time of day !

This is fixed for next release.


2020-12-15 10:57:00
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Joined: 2009-03-17 18:42:51
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Fixed in v1.28.2.1, released today.


2020-12-19 11:02:25
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Joined: 2012-08-08 17:51:35
Posts: 59
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Anyone else having issues with the sun trajectory for EE?
I can't imagine that the sun is supposed to rise in the east, climb to zenith, then back down eastwards again.
Two mornings and no sunset in the day cycle. :lol:


2020-12-20 15:02:07
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Joined: 2009-03-17 18:42:51
Posts: 4751
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Jessica Hultcrantz wrote:
Anyone else having issues with the sun trajectory for EE?
Not seeing anything like that here... Please, provide repro steps and logs !

Be aware that Extended Environment allows to set the Sun (and Moon) rising and setting points. To check how the Sun orbits for your current settings, open "World" -> "Environment settings" -> "Local environment editor", "Sun & Moon" tab, check the "Fixed time" box and use the slider on its right to see the Sun position depending on the time of the day.


2020-12-20 15:31:23
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Joined: 2012-08-08 17:51:35
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Steps to reproduce:
Look at anything inworld that casts a shadow, like a tree, a flagpole, whatever. (Obviously you need sun and moon shadows enabled).
Open "World" -> "Environment settings" -> "Local environment editor", "Sun & Moon" tab, check the "Fixed time" box and use the slider on its right to slide through the part of the day when the sun is above the horizon.
Watch the shadows, they are first cast from center of whatever towards west (natural for a sunrise at east), reaching midday they are mostly not showing (as sun is in zenith), and when you continue the day cycle the shadows does not turn east, they go back west and sun heads towards east.

Alternative step to reproduce:
Find an inworld time on the afternoon (EE/WL time), and compare shadows in EE / WL, they are cast 180 degrees against each other, while they are cast the same way in daytime before noon.

You can of course also look at the horizon east, and go through the EE day part with the sun above horizon. Don't look west, nothing to see there.


2020-12-20 20:31:38
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