#2507 Scenery issues with area around LFLP

[Megaf]

LFLP Area Is Invisible

That's an odd one.

Description:

Assuming scenery is correctly downloaded/installed.
When you spawn at LFLP you spawn in a void as if you are under the terrain, you can see nearby chunks of scenery loaded but not the one you are at.

Demonstrating the "missing" chunk.

Spawning with the UFO and flying away you indeed see that the whole chunk is invisible, but once you increase the viewing distance or move even farther back the chunk magically appears.

Chunk invisible at regular draw distance.

At standard draw distance in basic weather or in advanced weather this is what we see. Notice chunks beyond LFLP are loaded but LFLP isn't.

Chunk shows up when draw distance is increased.

But upon increasing view distance even further the chunk decides to show up.

Source/Refferences:

Bug originally found and reported by sfr on Discord
https://discord.com/channels/269552151997448197/269552670744903680/796107516173877269

[James Turner]

Which FG versions is this? 2020.3 or next?

@stuartbuchanan any thoughts on this?

[Stefan Frank]

i'm on next (compiled on the 10th of December)

[Megaf]

sfr and me we are both on next, His build is from roughly 1 month ago and my build is from yesterday. Though I'm not sure that's a version sensitive bug?

[James Turner]

If it's on next, there's been many small changes which could give a difference. However, from the information above, it's not clear (to me, anyway) if Stefan and you (Megaf) see identical behaviour or not?

[Megaf]

It's the very same behaviour indeed @jmturner

By the way, if just after spawning, you don't move at all, the scenery will become visible as soon as you increase viewing range.

[legoboyvdlp]

I saw something similar at Hamburg today with snowy weather (poor visibility); incidentally if I set weather to fair weather it would show the scenery again.

[Anonymous]

Could be related to https://sourceforge.net/p/flightgear/codetickets/2438/ (see the last post: visibility affects tile loading)

[Fahim Dalvi]

I've been noticing some oddities while flying recently as well, with nearby tiles suddenly dissapearing (usually just one), surrounded by loaded tiles. I also noticed something similar (maybe multiple issues) while doing tests for the new shader lights:

https://www.flickr.com/photos/191633981@N02/50814774047/in/album-72157717716638856/

In this, I first dive down into the ground with the ufo. It seems under the ocean is another layer of ocean, followed by a perpendicular layer of ocean. I then travel backwards to my starting point, increase visibilty and suddenly the nearby tile loads. I decrease it down to ~4000m, and all tiles dissapear.

Happy to provide more input/test stuff!

P.S. FG was started with the following:

    --timeofday=noon  --visibility=5000 --enable-fullscreen --aircraft=ufo --lat=-9.000331 --lon=-128.998400 --altitude=107.44 --heading=265.8 \
    --ignore-autosave \
    --model-hz=60 \
    --disable-ai-traffic \
    --prop:/sim/ai/enabled=0 \
    --disable-sound \
    --disable-ai-models \
    --disable-clouds \
    --disable-clouds3d \
    --fog-fastest \
    --visibility=5000 \
    --disable-distance-attenuation \
    --disable-real-weather-fetch \
    --prop:/sim/rendering/shaders/skydome=true \
    --metar="XXXX 012345Z 15003KT 12SM 20/08 Q1015 NOSIG" \
    --prop:/sim/rendering/fps-display=true \
    --prop:bool:/sim/rendering/als/shadows/enabled=true --prop:int:/sim/rendering/als/shadows/sun-atlas-size=2048

Best,
Fahim

[Anonymous]

Try this patch, it does not fix it completely, but tiles will no longer disappear right under you.

It partially reverts this commit:

* 0982b2827 2020-11-08 | WS3.0: Initial commit of WS3.0 rendering [Stuart Buchanan]

[waldo kitty]

i can confirm this on next, too... these pics are in the UFO... the 2nd one is one hit of the HOME key, to increase elevation one point, above the 1st one...

i can provide FG options if needed...

OSG 3.6: ddbed23537ce74c6a3223d59bfb8cf349acfd677
Simgear: d4a7cb1ee2e61c40b8fde9c1bb8f21403d0c3cfc
FGFS   : d3a11d72bbfcd429dce7b59343f1a837fb5680cb
FGData : c6b8869fed373f206920b404da9f03f7ffce69ff

[xDraconian]

Resolved. An out of range object caused the tile to unload.

[Fahim Dalvi]

Hi xDraconian,

Thanks for debugging this; The missing tile in the ocean issue I commented about still exists with the latest next though, so maybe its a different issue. Its also in the middle of the pacific ocean, with no scenery around to cause an out of range object I think. Shall I create a new ticket for that one?

Best,
Fahim

[Anonymous]

There is already ticket on it: https://sourceforge.net/p/flightgear/codetickets/2438/

[Stefan Frank]

hi xDraconian,

i'd like to better understand this issue. You wrote 'an out of range object' was the cause.
Does that mean a scenery object defined the lod range? And you fixed it by removing it from the Objects XML file?

Thx, Stefan

[xDraconian]

Hi Stefan (@sfrsfr)

An object was defined within the tile that was outside the tile coordinates.

[Stefan Frank]

hm, interesting, thx