What causes Unity occlusion culling not working?

Objects are not marked Occluder or Occludee Static, the occlusion data is not baked, or dynamic objects are expected to be culled, so hidden geometry still renders.

How do I catch this when it only happens for some players?

Capture it automatically from the player's device with the full stack trace, the device and OS, the build, and a breadcrumb trail of what they did. That turns a vague complaint into a specific, reproducible issue you can fix without owning the hardware it happens on.

How to Fix Unity Occlusion Culling Not Working

Quick answer: Mark static occluders and occludees with the right static flags, bake the occlusion data, and understand that only static occlusion is baked.

Occlusion culling not working is usually unmarked objects or an unbaked scene. Here is how to fix it.

How to fix it

1. Mark occluders and occludees

Static objects must be flagged as Occluder Static (large blockers) and Occludee Static (objects that can be hidden) for occlusion to apply. Unmarked objects are not part of the culling.

2. Bake the occlusion data

Occlusion culling for static geometry requires baking the occlusion data in the Occlusion window. Without a bake, there is no visibility data and nothing is occlusion-culled.

3. Understand the static limitation

Baked occlusion culling works for static geometry; dynamic objects are culled as occludees against the static occluders but do not occlude. Do not expect moving objects to occlude others without other techniques.

Catching the ones you can't reproduce

The hardest version of this to fix is the one you can't reproduce — it only happens on a player's hardware, OS, driver, or save state, under conditions that simply aren't present on your machine. A report that says “it crashed” or “it froze” gives you nothing to act on, so the bug survives release after release while quietly costing you players.

Automatic error capture closes that gap. Each failure arrives with its full stack trace, the device and OS, the build number, and a breadcrumb trail of what the player did right before it broke, so even a failure you have never seen becomes a specific, reproducible issue. Fold identical failures into one signature ranked by how many players each hits, and your worklist sorts itself worst-first instead of arriving as a stream of vague complaints.

This is where a tool like Bugnet earns its place. Its SDK captures every Unity error automatically with the full stack trace plus device, OS, memory, build, and game-state context, folds duplicates into one grouped issue with an occurrence count, and ties each to the build it first appeared on — so you fix the problem that hurts the most players first and confirm it is gone when its signature disappears from the next release.

Reproduce it once with full context and the fix writes itself. The hunt is the expensive part.