Cocos2d-x v3.8.1 Physics Problem

[anieduard]

Hello. I have a problem in my game and I think it’s from the physics engine. So, basically I have some sprites on the screen and after I add physics bodies to them they disappear sometimes from the screen when I run the project. Can anyone help me please?

Thank you!

[OscarLeif]

Cocos 2d-x3.7.1 [Windows] scene with physics world fails when add transition to scene

I have seen this issue and for me it had to do with how fast the device was. High performance devices running release build will show this issue more consistently. But slower devices or devices running a debug build don’t have the issue as often. But it did not happen more often on Windows vs. Android vs. iOS for me. My guess is that it has something to do with delaying to add bodies in the PhyiscsWorld class and how positions of the sprites and bodies are initialized… but not certain. The b…

That’s a bug, right now it’s not fixed. So basically the problem is about teleport with the node physics they not appear always at the same place.

You can fix this issue using this two options (If someone else know another fix please tell):

• Override “onEnterTransitionDidFinish”
• Use an old version of cocos 2d-x, version 3.6 down don’t have this problem.
• Maybe not using transitions scenes.

Bug report here: https://github.com/cocos2d/cocos2d-x/issues/12567#issuecomment-122970403

[anieduard]

Thank you very much! I am wondering whether this problem appears if I use the box2d physics engine.

[Heyalda]

I am wondering whether this problem appears if I use the box2d physics engine.

When you use the built in physics wrapper in Cocos2d-x, such as using the cocos2d::PhysicsBody, cocos2d::PhysicsWorld, etc., then you are using code that provides a wrapper only around Chipmunk.

The bug is in the Cocos2d-x code that wraps the Chipmunk physics engine, not with Chipmunk.

So if you use Chipmunk or Box2D directly, then you will not experience the “teleport” issue.

[anieduard]

Now I understand. Thank you very much!