Alternative timing for tasks

Scripting Issues
1

Hi all -
I’m using Panda3D in an experimental setting, and am using timers to do things like record the user’s position / orientation at 5 Hz (every .2 sec). I’m currently using a task that calls itself with the ‘taskMgr.doMethodLater’ method after a delay of .2 seconds and then returns Task.done, but is there a less clunky way to run this kind of a timer?
Can you set up the timer to run every X seconds instead of every frame? For example, in the Vizard VR toolkit (a commercial package similar to Panda3D) you can set up a timer with ‘viz.starttimer( , , )’ and explicitly control the timing so that it’s only running when it needs to be.
Just wondering if a similarly elegant solution was available in Panda. If not, it might be worth integrating into future versions with task interval as an optional argument to the ‘taskMgr.add( )’ method.

2

Yep, your klunky approach is currently the best approach to do this in Panda. You’re right, that sounds like a fine addition.

David

3

Have you tried having the task run every frame and only record the data when task.Time is a multiple of .2? It would mean plenty of extra wasted computing, but might be easier than the doMethodLater workaround.

4

I am pretty sure there a ‘Task.again’ you can return (instead of ‘Task.done’), so you dont have to call ‘taskMgr.doMethodLater’ each step.

5

I suppose you could emulate this kind of timer: ‘viz.starttimer( , , )’ easly.

You could create your own task method that would automatically check a local time counter and see if he needs to run this frame or not.

class VizTimer:
  def __init__(self,begin_tm,end_tm):
    self.now_tm = 0
    self.before_tm = 0
    self.begin_tm = begin_tm
    self.step_tm = step_tm
    self.end_tm = end_tm
  def should_run(self,now_tm):
    self.before_tm = self.now_tm
    self.now_tm = now_tm
    return self.begin_tm <= self.now_tm and self.end_tm >= self.now_tm
  def handler(self,task):
    if self.should_run(now_tm):
      -- your code here --