"Why Does Realistic Gravity Feel Floaty in My Game?" – A Developer's Dilemma

The Problem
Recently, I came across a developer who was working on a game and asked:

"I set the gravity in my game to 9.81 m/s² (Earth's gravity), but the falls feel way too floaty. Why does this happen? Is there something wrong with my implementation, or is it just how players perceive it?" — @Phantom_TheGame

This is a fascinating question because it touches on the intersection of physics, game design, and human perception. Let’s break it down.

The user shared a video of a character jumping from a considerable height. While the height wasn't specified, the video indicated that the gravity applied was 9.81 m/s² (Earth's gravity) and that there were no other forces like air resistance. Using a video editor, I measured that the character took 1.27 seconds to fall. This led me to calculate the height and investigate why, despite being physically accurate, the fall felt "floaty."

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Why Does It Feel "Floaty"?

1. Calculating the Height: How High Was the Jump?
Since we know the fall time $(t = 1.27s)$ and the gravity $(g = 9.81m^2)$ we can calculate the height $(h)$ using the free-fall formula:

$$h = \frac{1}{2} g t^2$$

For example, if a character falls 7.9 meters, the time $(t)$ would be:

$$t = \sqrt{\frac{2h}{g}} = \sqrt{\frac{2 \times 7.9}{9.81}} \approx 1.27 \, \text{seconds}$$

This calculation is correct, so why does it feel "floaty"? The answer lies in how players perceive the fall, not in the physics itself.

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2. Field of View (FOV) and Peripheral Vision

The field of view (FOV) in games plays a huge role in how players perceive movement. In real life, our FOV is around 180 degrees, but in games, it’s often much narrower (60-90 degrees). This narrow FOV distorts our perception of speed and depth.

• Low FOV (60-70 degrees): Objects at the edges of the screen move slowly, making falls feel less intense.

• High FOV (90-110 degrees): Objects at the edges move faster, enhancing the sensation of speed.

If the game uses a low FOV, even a physically accurate fall can feel "floaty" because the player’s peripheral vision isn’t engaged.

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3. Scale and Proportions

The scale of objects in the game world also affects perception. If the environment isn’t scaled realistically, players may misjudge distances and heights.

• Example: If a character is 1.8 meters tall but doors are 3 meters high, a fall from 7.9 meters might feel shorter than it actually is.
• Solution: Ensure consistent scaling. In Unity, for example, use 1 unit = 1 meter to maintain realism.

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4. Lack of Resistances

In real life, factors like air resistance affect how we experience a fall. In games, these resistances are often ignored to simplify physics calculations. Without them, falls can feel slower or "floaty."

• Example: In Unity, even with gravity set to 9.81 m/s², objects can seem to fall more slowly due to the absence of air resistance or friction.

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5. Camera Movement and Perspective

The way the camera moves during a fall can also influence perception. If the camera follows the character too smoothly or slowly, it can make the fall feel less impactful.

• Tip: Add slight camera shakes or adjust the camera’s follow speed to make falls feel more dynamic.

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Recommendations for Fixing "Floaty" Gravity

1. Adjust the Field of View (FOV)

• Recommendation: Increase the FOV to 90-110 degrees. This makes movements feel faster and more immersive (while falling).
• Example: In first-person games, a higher FOV can make falls feel more intense.

2. Use Realistic Scaling

• Recommendation: Ensure objects are scaled realistically. For example, if a character is 1.8 meters tall, doors should be around 2 meters high.
• Tools: In Unity or Godot, use 1 unit = 1 meter for consistency.

3. Add Resistances

• Recommendation: Incorporate air resistance or other forces to make falls feel more realistic.
• Example: In Unreal Engine, you can tweak physics settings to add drag or increase gravity slightly (e.g., 2.8 times the default value).

4. Tweak Camera Behavior

• Recommendation: Adjust the camera to make falls feel more dynamic. For example, add slight camera shakes during the fall or speed up the camera’s follow movement.

5. Test with Real-World References

• Recommendation: Compare your game’s falls to real-world examples. For instance, record a video of someone jumping from a height and compare it to your game’s fall animation.

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Conclusion

Even with gravity set to a physically accurate 9.81 m/s², falls in games can feel "floaty" due to factors like FOV, scaling, lack of resistances, and camera behavior. By adjusting these elements, you can create a more immersive and realistic experience for players.

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Q:

• Have you encountered the problem of “floating” gravity in video games? Do you have any tips or corrections to share?

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References

• Unity Documentation - Manual: Physics
• Self-motion-induced eye movements: effects on visual acuity and navigation