osm2city.py development

[merspieler]

delay in loading is a "feature"....

The idea is, that objects that you don't see, don't need to be loaded... which is a good idea... (Until you do stuff like ray tracing)
It obviously comes with the issue, you observed... as it starts loading when you switch/move the view and things come into sight.

[awen]

delay in loading is a "feature"...

Thanks for the explanation! I never thought that FG can detect what the user sees instead of rendering everything.

[wkitty42]

I never thought that FG can detect what the user sees instead of rendering everything.

if FG were to render everything, it could easily kill low spec systems from memory use... for example, the default pagedLOD of objects is set to 200... that's 200 objects... if you are in an area with thousands of objects, only 200 of them within the range will be displayed...

to explain this with a little more detail, i have another system with 32Gig RAM and a much much better GPU (RTX2060 [6Gig VRAM] vs GT730 [2Gig VRAM]) than my main system... on the new system, i have pagedLOD set to 4000(!)... the scenery looks much much better but FG starts off using a lot of system and GPU RAM, too... that system has 32Gig of system RAM... it starts up using maybe 1Gig before any of my apps are loaded... that puts FG using 6+Gig right out of the starting gate depending on where i spawn in... on a system with an OS that requires 4Gig of system RAM for the OS and only has 8Gig total system RAM, that leaves only 4Gig for FG to play in... i'll leave it to the reader to do the math to figure out what happens when you try to shove 6+Gig of stuff into a 4Gig hole

we won't even mention that an increased number of objects to be rendered and/or moved around could very easily bring one's GPU to its knees, as well... FPS can take a huge hit in heavily detailed areas depending on how those details are implemented...

[Paccidat]

Cool!

I wasn't aware of that setting.

My system is rather beefy, so by adding —prop:/sim/rendering/max-paged-lod=400 to the commandline I could double the amount of objects loaded?

And higher values if it can handle that

[wkitty42]

what version of FG are you running? newer versions have a slider in the in-sim F10->View->Rendering Options dialog... it is in the top left quadrant and titled "Maximum number of aircraft and scenery tiles"... you could set it there but yes, also using that prop line is fine...

[vanosten]

A short reply on the last 10 or so messages. The LOD loading behavior can be tricky. In FG NEXT a new parameter (which osm2city uses) is introduced to make some calculations more fair. So in the next FG version with osm2city built with FLAG_AFTER_2020_3 some of this should improve - but not everything has been coded yet.

When discussing osm2city please always tell where you got the scenery from (e.g. worldbuild) and/or whether it is using building lists (aka. shader buildings - visually detectable by "rectangular houses seems to look more the same and are darker"). The loading behavior is different. Building lists are loaded per tile and in worldbuild larger and smaller houses (the ones not in building lists) are loaded in squares (ca. 3x3 km), with larger buildings having the medium LOD and therefore typically loading sooner.
If you are not within LOD distance, then FG typically does not load it. See also https://osm2city.readthedocs.io/en/late ... ry-objects (I use larger distances with my graphics card). Therefore, you also need to mention your FG LOD settings when discussing such matter.
In upcoming osm2city with FLAG_AFTER_2020_3 some of this will change as more buildings etc. will be rendered per tile.

Lastly: as osm2city is relatively heavy on disk usage, putting scenery on an SSD does not hurt.

[merspieler]

So... I've managed to build with trees and it looks awesome...
But I've noticed two issues:
1st trees are placed in buildings:


and 2nd: it doesn't seem to use the local tree definition making a hard cut between random and osm2city trees:


I'll post the 2nd issue as well to the ml.

[vanosten]

There is no point in posting stuff to the mailing list, when it is related to osm2city.

And please as always: tile index, lon/lat or nearest airport, FG version, parameters used. Also I can see that the background is not standard BTG.

Also: did you just generate trees - or did you run everything from scratch for the specific tile?

[merspieler]

It's related to how flightgear interprets the tree list... so.. ml is probably the better place.

Tile: 5329469
Coords: 145.743556 -17.013742 facing south
Airport YBCS
FG: next, build at 2021-01-03
btg: same effect with default scenery
australia materials applied

[vanosten]

It's related to how flightgear interprets the tree list... so.. ml is probably the better place.

Tile: 5329469
Coords: 145.743556 -17.013742 facing south
Airport YBCS
FG: next, build at 2021-01-03
btg: same effect with default scenery
australia materials applied

I have replied on the mailinglist. What is missing are materials definitions in FGData with a fair set of regionalisation. The beauty of that is that no coding is needed, only experimentation and maybe a talk to me. See also https://gitlab.com/osm2city/osm2city/-/issues/176.

For the second issue: I would be interested whether you ran osm2city from scratch or only parts of it -> which -e option?

[merspieler]

Complete build.
Tho there was a previous build in that directory.

[vanosten]

My guess is, that the materials press stuff like trees through the photoscenery and you have not done: https://osm2city.readthedocs.io/en/late ... n-textures

[merspieler]

no, I didn't do that... but the trees have very distinct colors so I can easily tell osm trees apart from the random ones.

Also I've done a clean build with the same result.

[wkitty42]

would someone please kindly add some instructions to the docs on installing the prerequisites? i have no idea how to do that if i want to try to use OSM2City...

[merspieler]

In my install scrip I install the following packages:
git osmosis postgis pgadmin3 postgresql-contrib postgresql-client postgresql-postgis postgresql python-pip python3-venv python3-dev
Then I create a python venv and install the from the requirements.txt like so:
pip install -r osm2city/requirements.txt

You might as well want to take a look at easy-osm2city.