Box2D problem

[Outcast]

I have a problem in Box2D that I cant figure out. I am using the testbed as an example. It is in the forth frame of the testbed, the "Bullets" example I use. In the example you can steer a "cannon" with the mouse and shoot bullets at physics objects. I have stripped out all that for this problem. The problem occurs when I increase the timestep from 0.02 to 0.04 (I have added an event for this by pressing the space button)

The thing is though that when the timestep is set to 0.04 instead of 0.02 the "cannon" object is wiggling around as crazy. I have tried to figure it out, but I still have no idea how to fix this or what is causing it :/, any ideas?

[happygreenfrog]

Timestep is a coefficient for how much time is processed each step. Should usually be set to 1/FPS, e.g. 0.02 for 50 FPS.

Just sayin'. I didn't look at the example, but if you didn't double the frame rate in addition to doubling the timestep, that might be causing it..

[EdSabbath]

Actually being 0.04 step he'd need 25fps, not 100fps (0.04 sec opposed to 0.02). The reason it freaks out is because your framerate is higher than the framerate set in Box2D, so it can only handle the cannon every other frame. Either set your framerate to 25 (which would be sluggish looking! ugh) or set your Box2D step back to 0.02.

[happygreenfrog]

Oops! I see what you mean, EdSabbath! Sorry for the mistake! But the quote is accurate, at least.

[Outcast]

It was solved by cutting the force in half