Troubleshooting occlusion culling
Solve common problems when using occlusion culling.
Read time 2 minutesLast updated 24 days ago
Solve common problems when using occlusion culling, such as incorrect culling and slow processing.
Hidden objects aren’t being culled
Symptom
Objects are reported as visible in the occlusion data but are visibly occluded.
Cause
Culling in Unity operates conservatively. This means that unless the object is explicitly set as invisible, Unity will assume objects are visible.
Occlusion data represents a conservatively simplified version of the scene’s occluders, meaning some of the occlusion erodes and loses detail.
Resolution
Decrease the value of the Smallest Occluder parameter. This will produce higher-resolution data that is less conservative. However, culling will decrease in speed and occlusion data will increase in size.
Visible objects are being culled
Symptom
Objects are occluded incorrectly.
Resolution
- Decrease the value of the Smallest Hole parameter.
- Set the Backface Threshold to 100.
- Remove the Static Occluder flag from GameObjects that you don't want occluded.
Slow culling
Symptom
The culling process is too slow.
Resolution
Increase the value of the Smallest Occluder parameter.
Slow baking
Symptom
The baking process is too slow.
Resolution
Increase the value of the Smallest Hole parameter.
Large occlusion data
Symptom
The size of the occlusion data is too large.
Resolution
- Decrease the value of the Backface Threshold.
- Increase the value of the Smallest Occluder parameter.
Baking fails
Symptom
Baking fails with the error.
Failure in split phaseCause
The initial step of the bake tries to subdivide the scene into computation tiles. The subdivision is based on the Smallest Occluder parameter and when the scene is large in size, too many computation tiles can be created, resulting in an out of memory error.
Resolution
Increase the value of the Smallest Occluder parameter and split up the scene into smaller chunks.