RigidBody2D Jitter (never resting)

system · March 10, 2020, 2:50am


	Attention	Topic was automatically imported from the old Question2Answer platform.
	Asked By	babyblueboxers

Made a simple scene to test RigidBody2D physics. Dropping a “ball in a sink” kind of setup.

Node2D (root)
-StaticBody2D (The Sink)
--CollisionPolygon2D
-RigidBody2D (The Ball)
--Sprite
--CollisionShape2D

The RigidBody2D has a physics material with a bounce value of .6 and I drew a random shape for the StaticBody2D’s CollisionPolygon2D so the “ball” would have something to land on.

When the RigidBody2D bounces it eventually settles down into a point, but then it sits there and jitters (very rapid, minor movements. Shaking, shivering). It never enters the sleeping state or comes to a fully resting position. What am I missing?

system · March 10, 2020, 3:07am


	Reply From:	jgodfrey

Your description seems to be the same as this (apparent?) bug:

github.com/godotengine/godot

2D PhysicsMaterial bounce > 0, constantly agitated/vibrating when they should be at rest

opened 12:26PM - 21 Jan 19 UTC

closed 10:07PM - 25 Nov 21 UTC

hedgehog90

bug confirmed topic:physics

**Godot version:** 3.1.beta2.mono.official **Issue description:** If you pl…ace lots of objects in a physics environment with >0 bounce, they vibrate and never fully come to rest. I think setting the gravity higher makes it even worse. You can see this demonstrated in the 'Scene Instancing Demo' from the official demos repo (misc/instancing). It doesn't make sense that a ball with <1 bounce never comes to rest, there must be some strange and unnecessary impulse being applied behind the scenes.

I believe you are correct. Better still, it looks like the bug was confirmed recently. Hopefully it’ll be fixed soon. Thank you!

babyblueboxers | 2020-03-12 03:46