15. Foliage that follows edits, and PCGExperimental

Placed foliage follows the ground

When the ground changes (a sculpt stroke, a plate, a corridor), placed foliage moves with it, and is hidden where the ground no longer admits it: a cutting, a platform, a hole, or ground steeper than the foliage type allows. It is on by default.

• What follows. Instances of Unreal’s foliage actors follow. Any instanced mesh component follows when it carries the tag OrreryTerrain.Follow.
• Settings. Project Settings > Plugins > Orrery Terrain Follow. Foliage Follows Ground turns it off for all foliage actors (tagged components and per-type overrides still apply). Per foliage type you can choose a mode: Follow (snap to the new ground, hide where it is cleared), HideOnly (keep the height, hide where cleared) or Ignore. A margin setting clears foliage around a feature placed at runtime.
• In the editor. Foliage and tagged meshes follow editor-mode edits inside the same undo step, so one undo restores the ground and the instances together.
• At runtime. The runtime follower does not run in editor worlds that are not playing: its writes would be saved into your level.

PCG

The plugin has a PCG module, OrreryTerrainPCG. It needs Unreal’s PCG plugin, which is turned on with it.

• Get Orrery Terrain Data. A PCG node (category Procedural) that gives a graph the terrain as a surface. Use it instead of the Input node’s Landscape pin, which cannot see a Orrery terrain. Its settings choose the surface, the accuracy, the attributes and the point step. An optional Layer Set names the layer-weight attributes (Grass, Rock, …); empty, they are Layer0 to Layer15.
• Re-run on edit is opt-in. Without it a graph keeps what it generated. Add the Orrery Terrain PCG Refresh component to the actor that owns the PCG component. Its refresh mode is OnCommit (after a stroke ends, or at once for a commit, undo or load), Throttled (also during a stroke, at most the throttle rate a second) or Never.
• The Terraforming sample map has a PCG graph that places rocks and re-runs after an edit.

The PCG module is Experimental.