A question about the explanation of World.wait_for_tick() method in official document

[huan0808]

Hi,
I think this function is a asynchronous method to make client wait server to compute a frame.And if it hasn't done,we can make a loop in client to wait the server.

But in document's explanation it seems like a Synchronize method.

This confuzed me and if my understand is wrong please tell me why.
Thanks!

[germanros1987]

@sergi-e could you clarify this?

[yaknostoyok]

Hi, @huan0808!

You are correct, the Python API docs are misleading. What do you think of these changes?

• on_tick(self, callback)
  This method is used in asynchronous mode. It starts callbacks from the client for the function defined as callback, and returns the ID of the callback. The function will be called everytime the server ticks. It requires a carla.WorldSnapshot as argument, which can be retrieved from wait_for_tick(). Use remove_on_tick() to stop the callbacks.
  • Parameters:
    • callback (carla.WorldSnapshot) – Function with a snapshot as compulsory parameter that will be called when the client receives a tick.
  • Return: int
• remove_on_tick(self, callback_id)
  Stops the callback for callback_id started with on_tick().
  • Parameters:
    • callback_id (callback) – The callback to be removed. The ID is returned when creating the callback.
• tick(self, seconds=10.0)
  This method is used in synchronous mode, when the server waits for a client tick before computing the next frame. This method will send the tick, and give way to the server. It returns the ID of the new frame computed by the server.
  • Parameters:
    • seconds (float) – Maximum time in seconds the server should wait for a tick. It is set to 10.0 by default.
  • Return: int
  • Note: _If no tick is received in synchronous mode, the simulation will freeze. Also, if many ticks are received from different clients, there may be synchronization issues. Please read the docs about synchronous mode to learn more.
    _
• wait_for_tick(self, seconds=10.0)
  This method is used in asynchronous mode. It makes the client wait for a server tick. When the next frame is computed, the server will tick and return a snapshot describing the new state of the world.
  • Parameters:
    • seconds (float) – Maximum time in seconds the server should wait for a tick. It is set to 10.0 by default.
  • Return: carla.WorldSnapshot

[huan0808]

I think it's good now,thank you :)

[yshen47]

I also find it's misleading. could you update the documentation in the latest version? it is still like before