Confusion About Use of Physics Substepping - Doesn't Appear To Be Applying

Development Programming & Scripting
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I know, hardly the first post to express the title sentiment. My general understanding of Substepping is as follows:

  • AddForce automatically accounts for any necessary DeltaTime adjustments, so you don’t need to multiply in the delta to any forces you apply.
  • However, at a variable framerate, jitter can still occur as forces change. Applying a force on Tick might mean applying it 60 times a second or 30.
  • Substepping ticks the physics simulation multiple times a frame to help stabilize it, using small fixed timesteps rather than larger variable ones as much as it can.

I’m experiencing highly notable issues with a hoverboard-style setup (4 forces applied on Tick holding up a rectangular prism) where everything is smooth and balanced at 60 FPS but takes a turn for the worse anywhere lower. I have substepping enabled on the default settings, but can’t really tell the difference between having it on and off. Am I misusing the tech, or could there be another solution to my issue? I’ve been trying to achieve a degree of framerate independence, and so far, that goal seems to lead to a lot of differing opinions online. Any help appreciated; thank you!

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I will start by saying that I’m not an expert on the physics implementation.

That being established, this is a simple hovering cube at t.MaxFPS 10, no sub-stepping, default physics settings.

You’ll need to show how you are balancing your forces.

To avoid such issues I would suggest you turn off physic’s gravity, calculate all your forces including a force for gravity and then apply a single force. That way your artificial gravity will be included in your calculations. Moreover the most common behavior (hovering) will not depend on any calculations and will be the default (i.e. not frame-rate dependent and smooth)