The online racing simulator
Invisible cars for players downloading mods
When a player is downloading a mod then he cannot see players who are driving this mod, he can only see them on the minimap. However they can see him and will get crashed by his car. People are getting unjust bans because it makes them look like they are using ghost hack and/or crashing on purpose.

The real question for me is: how can it even happen?

Patch 0.7C: https://www.lfs.net/patch-7c

"Mods in use are downloaded while you are joining a host"

I don't want to be too quick to judge, but I guess if people don't want to upgrade, so they drive around ramming people they can't see, then they have only themselves to blame!

I mean, I've already coded to make this a rare event. Maybe it's time to change the allowed version, so 0.7C or D are required?

Or maybe this is happening by some means I don't yet understand.
Oh Ok, I guess using a version older than 0.7C could be the issue then.

I asked the player from the vid what version was he using but he hasn't responded yet so I'll get back here when he does.
He said he had 0.7D so it seems there's something else going on Shrug

He also said this: "at the time being i had very slow connection and downloading the mods took ages".

And: "actually i found that replay and it was 100% 0.7D, now when all mods are downloaded on the replay its visible im crashing those cars, on the recorded video and live they werent visible untill all mods were downloaded"
Quote from Scawen :>The real question for me is: how can it even happen?
>"Mods in use are downloaded while you are joining a host"
>Or maybe this is happening by some means I don't yet understand.

This happens when player joined a server, but mod was published or updated later. So player will download the mod again
The only other explanation that comes to mind seems unlikely:

he was already on the server
the funny cars joined, and his computer has never seen them
download is initiated on his computer
the people with the funny cars start driving around
he has a super slow internet connection that takes ages to download mods
when he encounters the cars, he still hasn't downloaded the mod yet

Or maybe there's some unknown bug, where LFS doesn't download mods? But I haven't heard of that so at this point I am clueless. We used to hear of a bug where people very distant from the Netherlands had trouble downloading mods.
Quote from iiiiil :This happens when player joined a server, but mod was published or updated later. So player will download the mod again

Is it common for a mod to take half an hour to download? On my computer it's just a few seconds. OK, my connection is quite good and I'm not too far from the Netherlands. But we are talking like 5MB, how long can it take?
In this case I wasn't playing for a while and obviously lots of mods had to be downloaded. Adding to the equation slow connection and maybe it was possible. Not sure if LFS is trying to download only those mods driving on the track or every new available.
Thanks, LFS should download all mods currently in use on that server, while you are connecting (if guest and host are both on version C or D).

After joining, it should get any new ones that join the race after that point. I think downloading after you have joined is slower, so that's why it tries to get them all while you are joining.

Maybe if you have the replay I could have a look to see if I think of anything.
I think joining the track should be blocked unless all mods driving on the track are downloaded, additional check before player try to join.

Replay is attached to this post Smile
Attached files
WE3X_0R_22.mpr - 20.3 MB - 138 views
Quote from texxxas :I think joining the track should be blocked unless all mods driving on the track are downloaded, additional check before player try to join.)

Problem is when you were joining the track those funny cars (PEEPEE50) were not on the track yet, I believe first one (nickname YEET) joined after minute 25 in the replay when you were already driving.


I don't know too much about networking but it seems strange to me that if one's connection is so bad that he is downloading a 5.4MB mod for over 5 minutes (the incident happened cca 5 minutes after the first funny cars joined but who knows how long did it actually take to finish the download) then how come the other cars are not lagging like crazy?
Quote from LakynVonLegendaus :Problem is when you were joining the track those funny cars (PEEPEE50) were not on the track yet, I believe first one (nickname YEET) joined after minute 25 in the replay when you were already driving.

Good point, that means this case cannot be prevented in any way. The only way would be to spectate player if mod is not downloaded in some declared time but this would be silly.
Quote from texxxas :Good point, that means this case cannot be prevented in any way. The only way would be to spectate player if mod is not downloaded in some declared time but this would be silly.

The client does receive position updates though (the cars are visible on the minimap) so maybe at least show some placeholder shape while the mod is downloading. Maybe not a very elegant solution either but better than a completely invisible player I think.
Thanks for the analysis.

I am puzzled why it takes so long to download the mod as it seems like a relatively small file. But I have seen other people get this slow downloading issue. Texxas, are the mod downloads reasonably fast while you are joining the server, and only slow when you are in game?

Lakyn, I agree, it would be good to see something. I thought maybe it could be simply the player name jumping along the track each time a position packet arrives, similar to the text that appears above a lagging car. I've had a look in the code and there are a couple of obstacles, such as Draw Style = zero and Radius = zero, so it doesn't get added to the frame draw list and culls it if it is added to the list. So it's not so simple as changing a line of code. I tried. Smile

It's obviously not insurmountable. I've made a note on paper to consider this at some point.
Quote from Scawen :I thought maybe it could be simply the player name jumping along the track each time a position packet arrives, similar to the text that appears above a lagging car.

Perhaps I should have mentioned in the OP that in the comparison video the video on the right is from a replay of another player, and as you can see Texas' car is not lagging in the replay so his position updates are being received fine. And I assume that if his position updates are being received by the server (and by clients of other players) then his client can receive position updates of other cars/mods just as frequently/smoothly (even position updates of cars/mods that he is currently downloading). So the player name text (or a placeholder shape or whatever) of the "ghost cars" would not be jumping along the track, it would be moving smooth. Or I just misunderstood what you meant by "jumping along the track" Smile

In any case, I'm afraid showing just a player name above the "ghost car" wouldn't really do much. I don't think people would try to avoid a collision with a text Smile And some people could have player names above cars hidden so they wouldn't even see that. That's why I suggested to show a placeholder shape. I don't know if it's possible for the client to get width,height and length of a mod before it actually gets downloaded but if it is then the shape could just be a simple cube with these dimensions. It would be ugly as hell but at least the player would see it and be forced to try to avoid collision with it (the shape would also have to carry a collision model I guess).

What you said after what I quoted - no idea what any of that means haha but I understand it might to be an easy fix. Maybe it doesn't even happen that often to be given a higher priority, it's hard to tell unfortunately. Although I must say that on our server we did have quite a few occasions where the player's behaviour just didn't make any sense and this bug would indeed explain it.
Quote from Scawen :Texxas, are the mod downloads reasonably fast while you are joining the server, and only slow when you are in game?

They were downloading slowly either when joining the server and while being in game. Sometimes it took a few minutes before I entered the server.
Quote from LakynVonLegendaus :When a player is downloading a mod then he cannot see players who are driving this mod, he can only see them on the minimap. However they can see him and will get crashed by his car. People are getting unjust bans because it makes them look like they are using ghost hack and/or crashing on purpose.


happened to me today, 3 cars were not downloaded, 3 people were invisible
For people who experience slow mods downloads, I have done a test in Test Patch D10.

Internet research has yielded little. This test is based on very little evidence, but I think it's worth a go. You need to enable it in Misc Options.

https://www.lfs.net/forum/post/2035565#post2035565
Quote from Scawen :Thanks, LFS should download all mods currently in use on that server, while you are connecting (if guest and host are both on version C or D).

Maybe there should be an option to download all mods currently allowed on that server?

Online players often go great lengths to ensure that no downloads/programs interrupt the game or cause lags. (Closing messenger programs, turning off updates/pop-ups, stopping downloads etc)

So why not pre-download all mods before joining?
It would probably need to be limited to some maximum number of mods. It is unfeasible to pre-download hundreds of mods like allowed on a cruise server. But if a server only allows 5 or 10 mods then I would prefer a short wait during joining over potential problems/lags while driving.
Quote from texxxas :They were downloading slowly either when joining the server and while being in game. Sometimes it took a few minutes before I entered the server.

Hi texxxas, if your location is Poland then I don't think you'll get any benefit from the new D20 redirection system. If you always get slow downloads, we might get some a clue if you could try a MTR (My Traceroute) from your location.

Info in this thread in test patch section: https://www.lfs.net/forum/thread/103323

Thanks.
Sorry to bump thread - any one has experienced mod desync in current or latest ver of LFS? Thanks.
I don't know if it's related to the topic, but I will respond to this issue.

I think everyone is having this problem. But sometimes I don't want to bother reporting it. I experienced this problem 18 days ago. I saw this while watching my videos.

See 00:45 to 00:52. When I crash, someone comes out of the pits. At that moment my game drops. You can notice this in the video.

https://youtu.be/uS3hRhf6hn4
Quote from RealistAdam :I don't know if it's related to the topic, but I will respond to this issue.

I think everyone is having this problem. But sometimes I don't want to bother reporting it. I experienced this problem 18 days ago. I saw this while watching my videos.

See 00:45 to 00:52. When I crash, someone comes out of the pits. At that moment my game drops. You can notice this in the video.

https://youtu.be/uS3hRhf6hn4

Think that's just rendering lag from mod menu loading... I'm referring to ghost cars (dots on map) where the user and his mod fails to load completely and other drivers can't see him on their screen. Is this issue still persistent in this version of LFS - and is physical collision still enabled for the ghost vehicle?
We experienced the problem you mentioned when test patches were available. We already reported this and it was fixed. I did not encounter this problem in the new version.

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