Physics accelerated bug?

Hello there!

After updating to v177, I’ve noticed that the physics for my arrows randomly shoot in almost straight line with double (or more) speed (probably just randomly get more force than supposed to). I can be holding down the fire button and it does that for an attack, a few attacks or a long time and then just randomly works fine again.

I have two identical game builds as I have the old v172 on my laptop and without any changes, it works without fault on that GDevelop build. The code is identical - as confirmed by github as well. I’ve tested both builds for 10 minutes, the v177 build (tried 178 too) is the one that makes it happen.

I have no errors to give, sadly. I used the console to track errors. Can I track it somehow?

Were the physics touched in the newer versions? Arrows use Physics2.0.

Any help would be appreciated as I cannot find the issue in the code, which I didn’t even change.

These are the only events for the physics of the arrow, if it helps (Once again, it all works fine on v172):

Maybe I’m not the best person to give you a precise answer, but if I understand correctly, they have adapted the force physics according to the frames per second (as I have seen the summary of what’s new with the latest versions "Fix Physics behavior forces effect under 60 FPS "). Does your game run at 60 FPS? Because perhaps this correction is what modifies those force values.
Naturally, the forces were applied to each frame and for this reason, in the same game that runs at different FPS, the objects to which the force is applied will have a different movement speed (if the game runs at 30 FPS, that force is applied 30 times per second; if the game runs at 60 FPS, it is applied 60 times per second, double that). I don’t know if they have adapted this to make it independent of the FPS (something that would be beneficial), perhaps someone on the team can answer it precisely.

That does make sense, but that is a weird change. Some games will fluctuate in FPS (worse computers etc.), which means that the physics might be inconsistent due to that result? I will check the FPS when I get the chance, but I feel that the “fix” isn’t really a fix.

The “force” action should only be used when a force is applied over time like thrusters for instance.
To give an initial speed to an object, either use the “impulse” or “linear velocity” actions.

I’ll try to make the actions descriptions clearer.