In Godot, how can I use different culling distances for 2 different layers with a single camera?

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Summary

In Godot 4, using different culling distances for multiple layers with a single camera is not a straightforward process. The engine does not provide a built-in feature to adjust culling distances for individual layers on a single camera. However, there are workarounds to achieve this functionality, which will be discussed in this article.

Root Cause

The root cause of this limitation is that Godot 4‘s camera system is designed to apply culling distances uniformly to all objects within its view frustum. This means that:

  • Near culling distance is applied to all objects to prevent z-fighting and ensure proper rendering of distant objects.
  • Far culling distance is applied to all objects to prevent unnecessary rendering of objects that are too far away.

Why This Happens in Real Systems

In real-world game development, this limitation can lead to:

  • Z-fighting issues with distant objects if the near culling distance is set too low.
  • Performance issues if the far culling distance is set too high, causing unnecessary rendering of distant objects.
  • Rendering artifacts if the culling distances are not properly balanced.

Real-World Impact

The impact of this limitation can be significant, leading to:

  • Poor performance due to unnecessary rendering of objects.
  • Visual artifacts due to improper culling distances.
  • Increased development time to work around this limitation.

Example or Code (if necessary and relevant)

# Example of using two cameras with different culling distances
var camera1 = Camera.new()
camera1.near = 0.1
camera1.far = 1000.0

var camera2 = Camera.new()
camera2.near = 0.01
camera2.far = 100.0

How Senior Engineers Fix It

Senior engineers can fix this issue by:

  • Using multiple cameras with different culling distances and rendering them to separate viewports.
  • Implementing custom culling logic using GDScript or C++.
  • Utilizing Godot 4‘s rendering pipeline to create a custom culling system.

Why Juniors Miss It

Junior engineers may miss this issue due to:

  • Lack of experience with 3D rendering and culling techniques.
  • Insufficient understanding of Godot 4‘s camera system and its limitations.
  • Failure to properly balance culling distances and rendering settings.