Corona physics doesn't work as they should. Joints stretching a lot.

Solar2D General Questions/Discussion
#1

I already have seen posts regarding corona joints stretching, from years ago, but they look to be insolved yet.

A piston joint, set to move only on Y axes for example, still moves back and forth on impact.

I have done a lot of tries to be able to build a car that works. I used piston joints for the dampers, and revolute for wheels, but even this, I had to use distance joints to prevent the dampers from moving back and forth. That’s disappointing. Physics just doesnt work as they where expected.

What happens in this video, is completely crazy, non sense. I did all I could to avoid this.

The car just goes thru a static body, that is the ground, if it is at certain angle. Tried changing the density of the bodies to several different possibilities, changed to bullet, to no sleep, etc. Nothing solved.

http://www.youtube.com/watch?v=B0BJWU46E9o

If anyone have a tip to avoid this, I would appreciate.

#2

Have you tried 

 physics.setContinuous(false)   

It should prevent joint stretching, at the expense of possible “tunneling” 

#3

Hello. I already, tried this, but didnt work.

But I finally found a workaround to solve it. I changed the car physic shape and now I couldnt reproduce the bug.

N1NKMLy.png

#4

well. I whas wrong. The bug just got worst with my changes. Now joints stretch, with the car at normal position, sometimes.

#5

Did you increase the velocity and position iteration settings? Working with complex joints in Box2D is a somewhat risky business, especially when you have a fast-moving scenario like yours. However, the object should not be faling apart like that. Is there something about that particular piece of ground it collided with, or does it happen in several cases?

I know you’ve already been working on this for awhile, but I suggest that you check, re-check, and RE-re-check your joints, where you’re attaching them, and all of the properties you’re setting on them.

Best regards,

Brent

#6

Have you tried 

 physics.setContinuous(false)   

It should prevent joint stretching, at the expense of possible “tunneling” 

#7

Hello. I already, tried this, but didnt work.

But I finally found a workaround to solve it. I changed the car physic shape and now I couldnt reproduce the bug.

N1NKMLy.png

#8

well. I whas wrong. The bug just got worst with my changes. Now joints stretch, with the car at normal position, sometimes.

#9

Did you increase the velocity and position iteration settings? Working with complex joints in Box2D is a somewhat risky business, especially when you have a fast-moving scenario like yours. However, the object should not be faling apart like that. Is there something about that particular piece of ground it collided with, or does it happen in several cases?

I know you’ve already been working on this for awhile, but I suggest that you check, re-check, and RE-re-check your joints, where you’re attaching them, and all of the properties you’re setting on them.

Best regards,

Brent