Scaling very large scene down?

Hello,

I am developing an American football game and the field itself is to scale of what it would be in real life. This allows me to implement realistic physics to the ball (i.e. force applied by the quarterback, kicker, etc.)

The game itself is working great, but I am now porting it to AR. Since the field is so large, I need to scale it down significantly (0.002 to 1 seems to be a good size). This comes with some limitations in terms of the AR subsystems and the physics system itself.

I have already attempted scaling the Session Origin (now XR Origin), but this creates a very unstable environment in terms of keeping the planes tracked. The hierarchy is XR Origin → Camera, Planes with the Game Zone being separate (I have tried it with the Game Zone as a child of the origin as well with similar results). Changing the scale of the origin makes the game smaller, but at the cost of instability and movement of the center of the experience placed previously.

Are there any other options, like scaling the physics system down somehow so ragdolls and the ball physics still work normally, just at a local scale instead of a global one? Is there something I am missing when scaling the XR Origin that would make it function normally given some changes?

Let me know if there is any information on this, I have searched many articles and tutorials but nothing is very recent nor have any of the solutions presented worked ideally. Thank you

1 Like

I had exp

It looks like that you have problems with plane tracking and not with the physics, because you didn’t describe what exactly is happening to ball & ragdolls.

Did you try with other objects without scaling the object itself / XR Origin?
Are you dealing with Android and ARCore (via AR Foundation) in a room that is poorly lit?
Such a combination in Place Tracking gives the worst results. iOS with ARKit behaves better.

This is really more of a physics question than an AR question. Physics works the same way here regardless of whether your scene is rendered in AR or not. Here’s a link to the Physics forum which might be more helpful? Unity Engine - Unity Discussions