[Question]: Damping 1 is no energy loss?

[pabrams]

Your Question

In physics, isn't a damping ratio of 0 supposed to bounce forever, and a ratio of 1 means don't bounce at all?

Should the parameter labelled "damping" in the UI actually be labelled "coefficient of restitution"?

Context

No response

Environment (if relevant)

• OS edition:
• Tool/Extension version:
• VSCode/Node version:

Additional Information

No response

Code of Conduct

• I agree to follow this project's Code of Conduct

[mattqdev]

Hey, I always had this doubt, so honestly I don't really know. this is the response of chatGPT:

Great question — this is a very common source of confusion because “damping ratio” and “coefficient of restitution” describe two completely different physical models.

⸻

1️⃣ Damping ratio (ζ)

Used in oscillatory systems like:
	•	Mass–spring–damper systems
	•	RLC circuits
	•	Structural vibrations

For a second-order system:
	•	ζ = 0 → no damping → oscillates forever at constant amplitude
	•	0 < ζ < 1 → underdamped → oscillates but amplitude decays
	•	ζ = 1 → critically damped → fastest return to equilibrium without oscillating
	•	ζ > 1 → overdamped → no oscillation, slower return

Important:
This describes continuous oscillation, not bouncing impacts.

⸻

2️⃣ Coefficient of restitution (e)

Used for collisions, like a bouncing ball.

e = \frac{\text{relative speed after impact}}{\text{relative speed before impact}}
	•	e = 1 → perfectly elastic → bounces forever (in ideal math world)
	•	0 < e < 1 → loses energy each bounce
	•	e = 0 → perfectly inelastic → no bounce

This describes discrete impacts, not continuous oscillation.

⸻

So should the UI say “coefficient of restitution”?

If the parameter controls how high the object rebounds after hitting something, then yes — it is physically the coefficient of restitution, not damping ratio.

If instead the parameter controls how quickly oscillations decay in a continuous system, then damping ratio is correct.

⸻

Quick diagnostic:
	•	Does it reduce velocity at impact? → Coefficient of restitution
	•	Does it continuously remove energy during motion? → Damping ratio

⸻

Why confusion happens

Game engines and physics libraries often label impact energy loss as “damping,” even though technically that’s restitution.

⸻

If you show me the exact equation or simulation behavior, I can tell you definitively which term is correct.

So I think your argument is right

[petercr]

I had the same question myself, and it does kind of sound like in this instance damping being set to 1 mean's it should bounce almost forever.
Which for the amount of time spent in the simulation, it's basically forever.

But I am of course not sure either. 😅

[pabrams]

Yeah, it seems to me that what that number actually corresponds to is the coefficient of restitution:

In physics, the coefficient of restitution (COR, also denoted by e), can be thought of as a measure of the elasticity of a collision between two bodies. It is a dimensionless parameter defined as the ratio of the relative velocity of separation after a two-body collision to the relative velocity of approach before collision. In most real-world collisions, the value of e lies somewhere between 0 and 1, where 1 represents a perfectly elastic collision (in which the objects rebound with no loss of speed but in the opposite directions) and 0 a perfectly inelastic collision (in which the objects do not rebound at all, and end up touching). The basic equation, sometimes known as Newton's restitution equation, was developed by Sir Isaac Newton in 1687.[1]

https://en.wikipedia.org/wiki/Coefficient_of_restitution

And damping is something different:
https://en.wikipedia.org/wiki/Damping

Furthermore, in the code, the ratio shown in the "damping"-labelled field ends up being used in a variable called restitution.

I'd suggest, then, that the label "Damping" is a misnomer, i.e. a minor bug.

[physicshub]

Yeah I think I agree with you about this, if you think that if anyone might be confused with the label, please create an issue or send a PR with the fix.
Thank you so much for raising this issue.