"This method can only be used inside callbacks." when calling simExtOMPL_isStateValid

[fferri]

From @SiyuanQi on August 19, 2017 2:23

Hi, I tried to run the API function simExtOMPL_isStateValid(number taskHandle, table state) from the embedded scripts and met some problems.

My final goal is to load a model during simulation, and set a valid goal state for that model. I use a associated child script for that model, and defined a function setTarget that calls simExtOMPL_isStateValid when executed. Task handle and state space are created in the initialization part.

Here are several scenarios:

• The model is in the scene from the beginning. Run setTarget directly from the associated child script. Works.
• The model is in the scene from the beginning. Call setTarget from a child script of a dummy object. Works.
• The model is created during simulation by the dummy object script. After one simulation round (made sure the model is initialized so the task handle and state space are created), call setTarget from a child script of a dummy object. Failed.

Here is the error message shown in V-REP:

Lua runtime error: [string "SCRIPT Bill"]:35: This method can only be used inside callbacks. (simExtOMPL_isStateValid @ 'OMPL' plugin)
stack traceback:
    [C]: in function 'simExtOMPL_isStateValid'
    [string "SCRIPT Bill"]:35: in function <[string "SCRIPT Bill"]:23>
Lua runtime error: [string -unknown location]:?: Failed calling script function. (simCallScriptFunction)
stack traceback:
    [C]: in function 'simCallScriptFunction'
    [string "SCRIPT engine"]:88: in main chunk

What would possibly be the reason for this? Thank you!

_Copied from original issue: fferri/vrepExtOMPL#2

[fferri]

From @aidyk on September 8, 2017 5:52

Hi, could you provide me a minimal sample code to reproduce it? I'm not a repository owner, but I'd like to investigate the issue.

[fferri]

From @SiyuanQi on September 8, 2017 17:33

Hi, I eventually solved the problem by adjusting the execution priority of the dummy object script to "last". So I guess it has something to do with the workflow inside vrep, e.g. when the initialization of an object is called if it is created during simulation.

[fferri]

From @aidyk on September 9, 2017 2:14

It's good anyway, and thank you for sharing your experience!