Quick answer: Unreal PCG graph rebuild discarding manual placement overrides? Rebuild treats overrides as side effects - separate authored content into a hand-placed layer.
Procedural foliage in a forest. Designer placed a hero tree manually. Rebuild removes it.
Separate hand-placed layer
PCG generates the bulk; hand-placed in a different sub-level. Rebuild affects only the procedural layer.
Or use exclusion volumes
Volume marks an area as 'manual'. PCG skips; manual placement persists.
Audit before rebuild
If overrides matter, snapshot. Restore manually after rebuild.
“Procedural systems and manual edits don't compose. Separate them physically.”
For projects with hand-placed hero content, the layer separation is non-optional. Plan it; document.