Unknown Physics change negatively affecting BodyMovers/Constraints

Bug Reports Engine Bugs
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#1

Undisclosed changes to the internals of body movers and/or physics constraints (we suspect) have resulted in breaking behavior in many of our games that are dependent on body movers/constraints for custom character movement. We haven’t made any changes to how we handle character controls, movement, or physics otherwise to influence this report being a false-flag, nor do we have the ability to fix this behavior directly as it is within the engine.

Expected behavior

Work like it did last week? I’m without context here, so I can’t give suggestions on behavior besides what history has provided.

9 Likes
Quaternion calculation behavior is suddenly dramatically different, causing major issues
#2

I have also noticed this with BodyPosition + BodyGyro in the past week or two. Wobbly plates in Sword Heights Royal seem more dangerous and less predictable than they previously were.

3 Likes
Humanoid Physics are unstable as of April 18 2024
#3

Do you still encounter the issue if you set Workspace.PhysicsSteppingMethod to Fixed?

1 Like
#4

All of our games use the Fixed Enum for PhysicsSteppingMethod

1 Like
#5

My game broke today and I lost nearly all of my concurrent players. I did not publish an update at all. Setting physics stepping method to “Fixed” does nothing for me.

This is my currently broken game. Is there any other changes that I can revert?
This is kind of urgent, my game is completely broken and will completely die if this isn’t resolved. Seems like theres absolutely nothing I can do myself to fix it either annoyingly.

3 Likes
#6

Hello all,

We just tried rolling back some Physics related flags, and we see improvements on our end. Can you please confirm if the issue is fixed on your end?

-ScipioAfrikanos

5 Likes
#7

I’ve tried testing in a brand new private server and my game is still broken. I also tried in a studio play test and its still broken.

4 Likes
#8

Hello,

The issue that they are describing is almost surely a result of the todays issues with Quaternion calculation. (based on the walking on walls). I just tested and the issue has still not been fixed in my game

I hope this helps diagnose the issue

2 Likes
#9

Video of the issues my game is now facing with physics.

Posted here as well: Release Notes for 621 - #14 by wravager

4 Likes
#10

Jailbreak is also affected by this … and is still broken even since latest flag changes.

When you get in ours cars (which use Body movers), you go soaring into the sky

8 Likes
#11

1 Like
#12

We’ve noticed this bug too, the screen will vibrate and it will allow you to jump super high. It only stops when you either sit or equip a tool.

2 Likes
#13

Hi,

After testing consistently in new private servers over the last 20 minutes, the issue persists. Tracking the flags we can see, it doesn’t seem like anything specific to client-governed character movement was flipped.

2 Likes
#14

it looks like FFlagSimSolverOptimizeIslandizerManager2 may be causing the issues, no longer happens to me after setting it to false

3 Likes
#15

Getting this in Deepwoken. Urgently needs a fix as players are dying and losing progress

3 Likes
#16

this just randomly happened to me ingame and I jumped then it broke my legs , I will start vibrating exactly like Arenoir said and be able to jump high but in this case it breaks my legs and is not intentional

2 Likes
#17

happening in my hockey game, and it’s interfering with my league :broken_heart:

1 Like
#18

@Sky_ogg thanks for that report, we validated that setting FFlagSimSolverOptimizeIslandizerManager2 to False has fixed at least some physics issues we’re seeing.

We just turned this flag off, please let us know if you’re still seeing physics issues in your games.

9 Likes
#19

They stopped happening for me, It was definitely the flag causing it

3 Likes
#20

Disabling the flag seems to have fixed the issues.

2 Likes