Multi player latency

As I've mentioned, I'm working on a space based game.

I'm noticing some latency if more than 3 players are in the same sector.

here's some facts:

1. I'm not sending x,y coordinates except when a new player enteres the sector and need to allow their client to know where everyone is.

2. if a player hits THRUST (up arrow) I send a channel message "T" on sub channel 1.

3. Players get that message and their client thrusts that player (in the direction the space ship is pointing).

this works quite well for 2 players. There are some positioning errors, but they are minor... once 3 or more players are in the same sector, the latency is pretty serious.

I may be using the wrong approach.

I send all thrust messages on sub channel 1

I send all left rotate messages on sub channel 2

Right Rotate is on sub channel 3

I did this to minimize the processing that takes place. Any message received on sub channel 1 is a thrust, no need to check what the data was.

would i be better off sending everything on 1 sub channel and checking what the message is? T for thrust, L for left rotate, R for right rotate, F for fire laser, etc?

Make sure that you are not sending "T" on subchannel one constantly, i.e.: only when event loops.

Yeah, that's not the issue, but thanks...

I'm asking the OINC experts really, looking for advice on what's considered a best practice to get the most efficient use out of oinc for a game like this. I'd think that handling 3 to 5 players would be relatively easy, but the latency is proving otherwise.

It depends on their physical location too. You didn't mention anything about your network setup.

When I test my games on klikfarm, there is quite a large amount of lag. And that's got nothing to do with klikfarm or OINC or my coding. It's to do with physical location. I live in Australia, by contrast klikfarm (as far as I know) is hosted in Netherlands.

Messages take time to get from Australia to Netherlands.

If I run a server from my computer and then run two client games I will see no lag at all. The game is instant, because it's obviously just connecting to localhost.

If I test my games with other Australians, hosting a server on my computer, I also have no problems with latency. My upload speed is relatively slow aswell.

So what's your network setup like? Are you running the server from your computer and getting friends in your country to connect to you? Or are you relaying information to klikfarm and then back to your country? Or are you hosting on your computer but playing with people from other countries?

You have to take all of these things into account. Even with modern games you can still get 300ms ping to international servers. Any gamers playing twitch-games would not even consider playing internationally.

Okay, for starters I would first investigate what netninja is saying, it's a good point. Because if you are in Texas and you are connecting to the Klikfarm then you should understand that a ping of 200 (where it takes a message 200 milliseconds to reach it's destination) is to be expected. For me, there's always this nasty shock when taking things from local host and then playing them on a public server with people from around the world. The quality of netplay shoots right down, as is to be expected.

So do some tests on how fast the messages are getting to the server, and if it's unacceptable, consider acquiring a Texas (or just American) based server.

Also, consider sending the angle along with either L or R. Because if the ship starts rotating out of sync, so it's at one angle at one client, and another angle on a second client, as soon as you thrust it is going to de-sync pretty much instantaneously. You don't need to be sending the X or the Y (at least, not regularly), but play with something like R46 or L320 where the start angle is in the message too.

In fact, now I think about it, I'm pretty sure this is the root of your problem.

I think this is a point you can feature in your upcoming course Dizzy.

You can get acceptable ping times using efficient coding but of course it wont get as good as using a localhost.

A lot of multiplayer games feature region based servers,
like us, europe and asia. You could think of having an international lobby server and perhaps have the possibility for users to connect to a selected region server.
This has pros and cons of course. Perhaps I will write an article on this.

I didn't completely take in the method you were using to send data, I just noted that you weren't sending "always" and moved on.

But after reading DizzyDoo's post and re-reading your original problem, you should definitely not be using 3 subchannels to send those sorts of messages. Or if you do you should be sending x/y along with them.

Thurst and angle are dependent on each other and therefore can't be executed at different times with the same result.

Just elaborting on what DizzyDoo said:
For example, if you send a rotate message on subchannel 2 and then 1 second later you send a thrust, you have sent 2 messages 1 second apart. However they will most likely arrive with a longer time between them (such as 2 seconds instead of 1), resulting in a significant sychronisation problem.

I also noted that you said that the positioning errors were minor and that the problem is latency. Could you please explain clearly what the exact issue is? Is it that when another client starts moving (on his screen) it takes a long time before you see him move on your screen? Or is it that the ships are out of sync with where they are supposed to be?

Wow, thanks, this is the kind of help I was looking for.

NetNinja: I've run tests using a LocalHost on my home network and 3 players. 2 of the three players run smoothly, while the 3rd seems to be quite difficult to keep in sync. I've also tested using server.klikfarm.com with very similar results. 2 players is nearly perfect.

DizzyDoo: Your suggestion about sending angle seems like a really good idea, and I will do that. I think the best place to do this would be when the thrust is sent. For the most part, rotating left/right appears to be very, very accurate in my tests, but I tend to agree that this could be the most significant issue when it comes to positioning the ships accurately.

NetNinja: By latency (or lag) I mean that with 3+ players, the clients don't seem to agree as to where each of the players space ships are. We set 3 laptops side by side and when 2 players are in the same sector, the two ships appear in nearly perfect position on both clients in the game. After introducing a 3rd and 4th player, positioning becomes noticeably inaccurate.

I'm going to make adjustments based on all this good advice and see how things work.

After that, if I can't manage to get good results, I'll post the mfa file and see if someone can spot issues I didn't consider. (a likely scenario in and of itself)

Thanks to all of you, I appreciate that everyone is so willing to help out!

If it's working fine with 3 ships and not 2, then I think it might be an issue with your code somewhere, especially if it does not work on a LAN/Local. Check your code which compares IDs of ships. It is possible that you may be moving the wrong ships when data is intended for other ships. Ie, on receiving the command to rotate client 2 you instead rotate client 3.

Having said that - you could be right! Maybe there is a problem with OINC and multiple connections. I've tested my games with multiple clients but I was using dead reckoning systems so perhaps they were masking some actual latency problems with OINC.

Maybe we should conduct some further tests?

Yeah, I just logged on to report that I think the cause of the problem has nothing to do with OINC...

To answer your question and to clarify a bit more: it works fine with 2 ships (not 3 as you stated, typo perhaps?). I do think the problem is with the clickteam movement controller and not with oinc. Oh, and the correct ships rotate when instructed, and thrust when instructed.

But i think the issue is with the use of the clickteam movement controller at this point. I have 1 movement controller for the LOCAL player and one controller for the REMOTE player.

When a 3rd player joins, I create a new instance of the Clickteam Movement Controller and the Remote Player Ship. Somehow, the remote players seem to get out of sync at that point.

Now, you mentioned that you're using dead reckoning systems... can you explain what you mean by that?

I'm not sure you need a second Clickteam movement controller, can one control multiple objects? If so, then your two movement controllers could both be trying to control both ships, and end up fighting.

ah, that's interesting, I wasn't aware that the CMC could handle multiple objects. I'll try it with just the one...

Great News, that seemed to help quite a bit... running on my local server with 3 clients running, everyone did fine.

I eliminated the additional ClickTeam Movement Controller(s) and that made quite a bit of difference.

I'm unable to test against the klikfarm server because it seems to have gone off line again.

I appreciate all the help.

Tuna

Yeah OINC has some issues, its a new test build that fixes a lot of bugs. But it's not stable. Sometimes it locks without any apparant reason.

Alpha stage guys ;)

I do notice that it crashes sometimes... my kids and I were all connected in my game running tests, sometimes when we disconnect from a channel the game would crash.

I don't complain about that because: 1, its been mentioned before and 2, you're right, it is still an alpha version.

I'm just happy to know that it does handle multiple connections quite well, and I'm in Texas... so the connection to klikfarm in the Netherlands is acceptable for my needs!

That explains the username Dad :)
Glad to hear the connection performance is good.
I think within a few builds the server will be stable.

That's great news! thanks for letting us use your server for testing... it makes life easier.

You might be interested to know that I can't tell much difference between running the server here at home vs. running against your server. There is only a tiny difference that I can tell.

Most of the work is being concentrated on the server at the moment, but after that I will fix the stability issues in the client.

Sounds good Jamie, thank you...

We're really having a blast with OINC!