Maximum Rigidbody2D velocity?

I'm noticing when I am changing the value of the velocity on a Rigidbody2D object it gets capped at -100. Any value lower than that I can set, but when the physics runs it just uses -100 and changes the value to -100.

Is this a hard limit or is there a setting to adjust this? I could get around this by scaling my whole project down but that seems like a lot of work when I don't see a real reason about it would need to be capped at these values.

Any ideas?

 

I'm finding the same, after attempting to use pixels as game/physics units, which makes the world scale much larger. Any help would be much appreciated!

 

I think your best option is scaling your world down. This issue seems to be common in the box2d world when people try using 1:1 ratio for pixels to world units. I believe the default values exist to prevent such issues with the physics system. You might try messing with the Physics 2D settings in the project settings area.

 

Ugh - yeah, I've just run into this too. Ideally Unity would just expose whatever pixels-to-unit ratio it is passing down to Box2D, so that the user could set it on a per project basis. For now though, looks like scaling down everything is the only viable solution.

 

@MelvMay - Just came across this thread and issue in my own game. I know this may be a tough one, but is there any timeframe on when that might be released? Like, months? Or years? Next update? Or backlogged?

 

When can we expect this? Is there any way we can ensure this for a release soon? Our project heavily depends on 2D physics and scaling everything down would be incredibly difficult at this point.

 

Yes, I would like to know too when we can expect this and also, I would like to know if some of these items will provide a way to disable or increase the maximum angular speed that currently affects the box2d physics and also if there will be a way to disable/increase that limit only for some objects (the wheels of my vehicle ).

Thank you in advance and good job!

 

Thank you for your reply. Yes, that's quite obvious, I just wanted to make sure we're talking about the same thing... it seems there will be no per-object configuration of 'Max Rot Speed" then... no big deal, although the other engine (physx) allows it, I think I could find a compromise between allowing my wheels to rotate fast enough and not destroying the simulation for other objects.

I was thinking about making something like the wheel collider using rays but it's not a good approach for a 2D game because you know, the 'ray' is only a single 'contact' point and, besides being a quite decent approximation for most 3d games and working okay for some 2d, I don't want it for my game, so, the next option is perhaps to create a circle collider (a static one) to use as the wheel and analyze its contact points and apply forces according to the contact points normals... it's quite easy on paper, you divide the 'motor' force by the number of contact points and apply the forces on each, however, last time I've played with contact normals the result were quite funky.

I think a way to simulate a wheel would be better than messing up with the 'max rot speed', but I couldn't find a way to get it working decently.

Thanks.

 

Any update? I upgraded to 4.x, added my first 2D physics behavior, and hit the 100 m/s max velocity by the end of the day. Course, it took me about an hour to figure out it was a Unity/Box2D limitation.

PLEASE UPDATE the Rigidbody2D.velocity documentation - add 'Box2D uses a cap on velocity of 100 m/s - while we work to increase that, you may consider rescaling all of your models to fit this limitation.' Searching the net shows 100s of posts on this - let's be good chaps and save the next folks some heart-ache.

Gigi.

 

While we're updating the docs please update:

https://docs.unity3d.com/Documentation/ScriptReference/Physics2D.Raycast.html

In particular if (hit != null) {

1. This appears to be pretty much useless.
2. People should be checking it as a bool instead, or if collider is null.

The reason it needs documenting is because Physx will be null and this won't be. It's inconsistent and confusing for new users learning.

 

I'm really curious about the update too... It is quite crucial for my project.
Exposing those variables would be a life saver.

 

I guess this still hasn't been added?

It's a real pain. I spent a few hours last night trying to figure out what was happening.

Any timeframe on when this will be fixed/exposed?

 

Haven't tested it yet, but as far as i see, they are exposed in 4.6.0f3. Try going to Edit->Physics 2D->Max Translation Speed and increase it. That should do it.