You can already reverse a spring function:

const spr: Partial<SpringConfig> = {
	damping: 200,
};

const duration = measureSpring({fps, config});

const two = spring({
	fps,
	frame: duration - frame,
	config,
});

But (even for me) it requires quite some mental gymnastics to figure that out.

Bounty

• Should implement a reverse parameter for spring() that takes care of this calculation (default false)
  • Important: Take into account the durationInFrames option!
• Should document in spring.md and label as available in the next Remotion version using <AvailableFrom>
• Write 1-2 unit test assertions