TrueSync Tutorial bug


The TrueSync tutorial appears to be buggy if all users don't enter the game at the same time.

Steps to reproduce are this:

- Create fresh project, import TrueSync and the tutorial package here:

- Build three separate copies of the game. (lets call them Game1, Game2, Game3)

- Open 'Game1' and 'Game2'... Two Players are now waiting in the lobby as expected.

- Master player then presses 'start' button... Two players are now in game and movement + controls are working well

- Open 'Game3'...
- Player3 seems to connect successfully, and goes straight past the lobby and into the game.
- However there are no other players,
- Game3 shows that there are 3 players connected
- Game1 and Game2 still only show that there are 2 players connected
- Input controls don't work at all for 'Game3'.
- 'Game1' and 'Game2' controls still work, but don't show the third player.

The expected/desired behaviour is that Game3 spawns a new player in all games upon joining the game.

Any ideas?

Many thanks


  • It's my understanding that you can't join a player to a TrueSync session already in progress because the new player won't have any way to know what position the objects are in the session. This is because trueSync simulates a physics simulation simultaneously on all connected clients when the session starts. A new player won't have that past simulation and the current input data from the other players won't be enough information to get caught up.
  • feathers
    Thanks Dan, that would make sense i guess.

    Wondering perhaps if the playback mechanism in truesync has this ability?
  • JeffersonHenrique
    Great answer Dan, you are totally right. And @feathers the Game3 should even connect, but the code is simplified for tutorial purposes. We have a way to send all previous players inputs, but this could take a lot of time to be simulated until Game3 have reached the same point as other players, it is still a topic of discussion the later-join feature.

  • feathers
    Thanks @JeffersonHenrique , having some time to wait is not really a big issue in the game i am building, however joining an existing game is a must-have. Could you please point me to some more information on the later-join feature?
  • JeffersonHenrique
    Hi @feathers, later-join is possible but this feature need that a new client simulates all the game until he reaches the current state, if it is on the first frames it is ok, but if the game are a lot of frames ahead this could take a lot of time to be resimulated on the new client, which is not a good thing. This is one of the main reasons we are stil discussing about later-join feature.