Quick answer: Unreal foliage painted in editor missing in PIE? The InstancedFoliageActor may not be in the level streamed by PIE — check World Partition or sublevel visibility.
Foliage is visible in the editor viewport but absent in PIE. PIE loads a subset of streamed cells, and the actor holding the foliage isn’t in those cells.
World Partition Foliage
In World Partition, foliage lives in the cell the brush was painted in. PIE only loads the cells around the player. If the player spawns far from painted foliage, it’s simply not loaded yet.
HLOD for Distant Foliage
Build HLODs (World Partition’s Builders → Build HLODs) so distant foliage shows a proxy. Otherwise you only see foliage in the current loaded cells.
Always Loaded
For unstreamed levels: put the InstancedFoliageActor in a sublevel marked Always Loaded. Or in World Partition, mark its cell as Is Spatially Loaded = false.
Verifying
PIE near painted regions shows foliage. PIE far away shows HLOD proxies or nothing — same as the runtime experience.
“Missing PIE foliage is a streaming question. Build HLODs and verify the player spawns near the cell.”
Run r.HLOD 1 in PIE to force HLOD display — helps you see when foliage falls off the loaded radius.