strange online-race collision

Discussion in 'Technical Archives' started by rene-xmg, Apr 24, 2013.

  1. rene-xmg

    rene-xmg Registered

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    Last edited by a moderator: Apr 24, 2013
  2. Lazza

    Lazza Registered

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    Probably lag mainly.

    Even with fairly low latency connections, let's say 50ms, there's still a lag between what the server gets (people sending their car positions in) and it getting to you. Plus the game can't be sending you information every single moment, so if the information on another car arrives at the server just after it sends to you, you'll have to wait for the next 'update' before your game gets the info.

    What all this means is the game has to predict what is going to happen, because obviously you can't wait and find out exactly where they actually were at a specific time - you're not there any more. For the most part the game uses the AIW (AI line, or driving line) to determine where a car is likely to go from its current position, and that includes braking.

    So, if you get a bit more lag than normal you can quite often see discrepancies like this, where your game 'sees' the other car on a certain line and braking at a particular point, when in actual fact that's not where they were. It's quite possible the server replay doesn't show what the other player saw either, though presumably it's somewhere between what they saw and what you did.

    Maybe you had a background process drain your available bandwidth at that moment, or for whatever reason your connection stuttered and the information was delayed. I've seen similar before but usually in unusual situations (not near the racing line, or braking where you wouldn't normally, etc) or where one person has a connection issue of some sort. rFactor is usually pretty good with steady connections and normal situations.

    We can't eliminate lag, so sometimes this is the price we pay for online gaming.
     

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