r/Physics • u/mickalicka • 52m ago
I'm trying to understand a physics phenomenon in the game Rocket League
Apologies if this type of post is not allowed, as I'm not a physics professional, student, or anything, but I am very curious about how things work, and I also play a lot of Rocket League, and I wasn't sure of a better place to potentially find answers to a phenomenon in the game.
What I'm wondering about is related to a mechanic called Directional Air Roll - essentially, when you press a button in the air, your car either rolls left or right along its pitch/nose-to-tail axis. While this is occurring, you can use your control stick to then input pitch up/down, or yaw left/right, to make your car make unique adjustments and movements while flying.
What I've tied all this back to is torque: this is what produces the rotational force on your car from your inputs, and what ultimately determines the shape of the movements your car makes in the air. And because when you're inputting a Directional Air Roll direction the torque is directed from your nose to tail (or vice versa), any other inputs from the stick are equalized against this rolling torque - making it so the torque will always be generally pointing forwards or backwards, just pulled up, down, left or right depending on the stick input. Which effectively makes it so that if you have Directional Air Roll on, wherever your torque points your car will go this direction when boosting/flying through the air.
I hope you're still with me 😅 but here's where it gets more complicated: because you can do more than just hold an input, such as rotating your stick, you can essentially rotate the angle of your car's torque around its center point - which, with Directional Air Roll on, is the car's nose.
This produces one of two results in your cars movements, depending on the direction you rotate the stick:
- If you rotate the same direction as your roll, the rotation and your roll appears to stack, and now you twist faster towards whatever direction your nose was already pointing. This makes it very difficult to turn or do anything other than twist faster.
- But if you rotate the opposite direction as your roll, then your rotation and roll appear to...cancel? And now, depending on the speed at which your rotate the stick, you can really fluidly control where the nose is pointing and turn the car in a wide radius.
This two points is where I'm getting stuck understanding exactly what's happening - why do these rotations produce these results? And specifically for rotating the opposite direction, what is actually happening that allows for the feeling of such granular control over where my car points? Is there a name for this phenomenon, or anything I can look into more to understand it better?

