Hinge joint 2D physics limitations

Unity Engine
1

Hello everyone! This time I have kind of big question.

I want to achieve one special effect in my 2D game. I have drawn a character and its arm:
1524726--87561--$character_new.png
I’d love to achieve kind of swinging effect of the arm. It should be connected to the body and swing according to (for example) the body’s speed (for example, when I run left after standing on place, the arm should rotate counterclockwise according to the First Newton’s Law, right?)…

So I want to create a hinge joint, but the HingeJoint2D component seems to be not very sophisticated (compared to HingeJoint)… Do you think it is even possible to achieve this via HingeJoint2D? I was experimenting with this, but no good result. Or is it better to write my own physics?

Thanks for any advice and, please, excuse my pretty lame English…
Have a nice day!

2

Yes the arm should naturally (automatically) dangle and swing according to physics. Just make sure you turn off the motor of the joint.

3

Well, for some reason, it does not work for me at all… Maybe I have set Anchor and Connected Anchor in a wrong way. If I have the sprite origin set to the “Top” (the anchor, basicly), should the Anchor be 0,0, or not? I’m not sure, but that does not work for me…

Thanks anyway, I’ll keep trying…

4

Well, a week ago I made this work, but I have one last problem. I connected the object “body” to object “wheel” via Hinge Joint 2D. But when I move with wheel, the body is not at it’s position, but there is a slight delay. The result is, the body is kind of flickering and tearing. Is that normal? I have been experimenting with settings for days, but no result. Any tips?

Thanks a lot!

5

Can you post a video? Or at the very least post a screen shot.

6

Well, solved… The problem was the body was a child of the wheel. I created a new game object a made body and wheel its children. Now I move with the new object and it works pretty well…

Thanks anyway!