I’m working on a simple game, with a ball rolling through some pipes. In Unity 4.3.4, everything was perfect with the default settings - no physics materials used, and the ball would roll very realistically. I upgraded to 4.5, now the ball just ‘slides’ when it hits an angled edge collider, it is as though the angular momentum is not being calculated correctly. Imaging the ball is falling straight down and hits a 45 degree angle - it does not acquire any angular velocity, it just bounces without rotating at all (in 4.3.4, it would acquire spin when it struck the collider). Then when it hits a horizontal collider, the lack of angular velocity causes it to stick (well not actually stick, just slow down unrealistically). I tried all combinations of material properties (friction and bounce) but this just made things worse.
I’ve just reverted to 4.3.4 and everything is fine again. Works in 4.3.4, broken in 4.5
Should I be doing something different in 4.5, am I missing something new, or is there a bug in the 2D physics?
Seems like a lot of extra work, but thanks for pointing it out. I think I’ll stick with 4.3 to finish this project, then upgrade again. Hopefully this will get sorted in a future version.
4.5 has broken a really trivial project that I’ve been messing with. It’s a ‘Thrust’-style game - a 2D spacecraft that can be rotated and have thrust applied. The ship would just seem to suddenly lose velocity every second or two.
I managed to reproduce it in a test scene with a single 2D rigidbody and no colliders, and found that if the object has been rotated manually (e.g. transform.Rotate) around Z, and has interpolation enabled, it will exhibit this strange loss of velocity.
Without interpolation, it was OK (but not smooth). Without the rotation but with interpolation, it was OK.
I submitted a bug, but it got marked as a duplicate (maybe of this one?) - but it’s definitely related to interpolation…
I have another thread in regular Support forum regarding this, but maybe it will get more thoughts here: I am noticing in 4.5 that my Rigidbody2D’s Interpolation isn’t working as smoothly as 4.3. I’ve changed nothing except Unity versions and now my character jitters badly all the time. Anyone have any problems with something similar? Thanks.
Sadly the patch released yesterday didn’t fix any of these issues. Super disappointed. Melv said the inertia bug would at least be there.
Many games rely on physics behaving as expected, and with the (confirmed) inertia calculation bug causing objects to roll nearly forever like they’re filled with water and the (confirmed) bug where 2D physics objects are no longer drawing any behavior from their Physics2D materials (bounce doesn’t work), 2D physics are completely ruined until a patch comes.
If you’re working on a game that uses 2D rigidbodies, do not under any circumstances upgrade to 4.5. It’s a mess, and those are just the bugs that I know of.
I really wish they would include more people in testing these major updates before they go out so obvious issues like this can be fixed first.
4.5.1 isn’t a patch, it’s a standard release. The issue was only raised after 4.5.1 was in the QA pipeline. The fix has been applied to the first patch for 4.5.1 which should be out soon.
The original change was out for many months during alpha and beta cycles but wasn’t reported. I would say that this issue doesn’t mean 4.5 “is a mess” and has been rectified pretty quickly after being reported.
How do we get access to the beta and alpha builds? It sounds like there isn’t many 2D tester involved right now if these bugs were never reported. It may not be a “mess” but it is unusable at the moment.
Yeah, I’m having real problems with interpolation in 4.5 (see my post a few comments up). Haven’t seen any acknowledgement of this as a bug though, and my bug was closed as a duplicate (they probably got hundreds of ‘2D physics is broken!’ bugs) - but I’m not convinced that this is the same bug as either of the confirmed bugs…
Hopefully it’s the same issue. I know I’m not losing my mind because I can hop back and forth between 4.3 and 4.5 and 4.3 is smooth and 4.5 is bizarre/inconsistent. I wasn’t able to reproduce in a small test project, however - so I’m wondering if it’s an issue when there is other stuff going on.
Though in my case, it has nothing to do with rotation. Also, I should add that this isn’t just an Editor thing because even when building and deploying to my device, the issue is still there.
I just checked that and yes, it’s marked as a duplicate of another issue reporting the same thing. Know that this doesn’t mean the bug report will be ignored, quite the opposite, as was stated in the reply to your bug report, the information you provided will be used in resolving the issue.
Oh, and there are currently 14 bug reports for 2D physics!
More importantly, forgot to mention that I’ll be looking at this issue later today!
So I’ve reproduced the interpolation issue and yes, there are a few reports producing the same effect. I’ll identify what’s wrong and get a fix into the next patch release.
Note that I reopened your case and fixed the interpolation issue against it. It wasn’t a duplicate after all but its description was identical to another case which was why it was unfortunately flagged as a duplicate.
