Strange sliding physics behavior in Unity 5.1

We’re working on a new multiplayer version of our game 99 Bricks (previously on mobile as 99 Bricks Wizard Academy). We’ve just switched from Unity 4.3 to Unity 5.1 and we’re encountering very strange physics behavior. When we’re building a tower, the bricks seem to be pushed outwards. I’ve included 2 videos of our auto builder tester, one in Unity 4.3 and the other in Unity 5.1. As you can see, the 4.3 is quite stable, but in 5.1 the bricks start sliding immediately and the tower collapses.

We’re using the 3d physics in both versions, we’ve tried adjusting all possible physics settings and materials, but nothing helps (including “Enable Adaptive Force”).

We have tried converting to 2d physics in unity 5.1 and that works as expected (no strange behavior), but the reason we used 3d physics in the past was that it gave the game a better gameplay feeling, so we would like to keep the 3d physics option open.

Is this is a known issue or expected behavior inUnity 5.1. Is there something we can do or is 2d physics the only way forward?

Have you checked the physics settings in Edit->Project Settings->Physics to make sure they are the same in your 5.1 project as in your 4.3?

Hey Joram,

Can I get you to report a fogbugz case on that? I’d love to take a look on the data. After filing the bug shoot me an email with the case# please.

Anthony

We’ve checked the settings and tried changing all the settings to see if we could solve this, but nothing works unfortunately.

Hi Anthony,

Thanks for your reply, do you mean https://fogbugz.unity3d.com or submitting a bug report from the Unity help menu?

Joram

Joram - you’re welcome to file this bug as any other one really - just use the built-in bug reporter tool right the Editor help menu. But please do let me know the case# so that I could dig it up in the stream of incoming bugs and investigate faster. Thanks.

Anthony, it’s done, the case# is 708498. I’ve included both the unity 5.1 project as the unity 4.3 project

thanks Joram! I’ll be coming to you by mail when I get my hands onto the report.