What is the difference between "Build Data" and "Rebuild Data" in the Nanite for landscapes, if that data was previously built?

Does the button “Build Data” REbuild only the necessary cells (in the World Partition etc.), or do I need to press “Rebuild Data” each time I sculpt the landscape or paint the materials on it?

Hey there @Etyuhibosecyu!

Generally you would only run the original “Build Data” when the first instance is being generated or when needing to be entirely rebuilt.

Rebuild Data is the correct workflow when adjusting painting or materials, as it also only affects cells that have been edited. This will save massive headaches with extremely large landscapes.

In 5.4 the rebuild system got an upgrade and should actually be automatically run after making changes to specific cells, though I haven’t tested it myself:

https://portal.productboard.com/epicgames/1-unreal-engine-public-roadmap/c/1452-landscape-nanite-automatic-async-build