Player built structures are partially buried in Landscape terrain
In my UEFN island, player-built structures, especially walls, are partially buried underground instead of sitting properly on top of the terrain. As a result, the bottom part of walls is hidden below the grass, and the entire structure is not visible.
I have already used the Landscape Flatten and Smooth tools across the island, but the issue persists during gameplay. It also occurs in my privately published island, not just in the UEFN editor session.
How can I fix this? Is this a known issue with Landscape terrain, player building placement, or collision settings? I have attached a screenshot showing the problem. I want player-built structures to sit correctly on the terrain without having to rebuild my island.
Player-built walls are partially buried in the Landscape terrain, with the bottom section hidden beneath the grass. This happens during gameplay and also in the privately published version of the island. I have already used the Landscape Flatten and Smooth tools across the island, but the issue persists. The terrain appears relatively flat, yet the structures still intersect with the ground. I have attached a screenshot showing the issue.
Flatten and Smooth only edit the heightmap the editor draws. Player building does not snap to that visual surface. It traces the landscape collision, and the grass you see is often not that collision.
Check these in order.
Landscape material. If it uses World Position Offset, Pixel Depth Offset, or a grass layer that lifts the visible ground, the rendered terrain sits above the collision. Walls then look buried even on a flat island. Temporarily swap the landscape to a default material with no offset. If the walls pop up to the surface, the material is the gap, not the building system.
Collision mip. Select the Landscape, set Collision Mip Level to 0, and rebuild collision (resave the island so UEFN recooks the heightfield). A coarse mip is a constant sink on flat ground and a bigger one on slopes. A privately published island often looks worse than the editor session for this reason: the cooked collision is the coarse mip.
Separate “only player walls sink” from “everything sinks”. Drop a static prop with collision on the same spot. If the prop sits correctly and only built walls sink, the building grid is below the landscape. Raise that grid in the island building settings instead of resculpting. If the prop sinks too, it is the collision-versus-visual gap from the first two checks.
Grass itself has no collision, so a short bury that is only the bottom of the wall sitting in the grass card is just grass height. What you described sounds deeper than that, so rule out the material offset and the collision mip before rebuilding the island.
