Last year I had a project where I needed to create a landscape on top of Cesium terrain. The thing is — streamed terrain can’t be edited. You can’t sculpt it like a normal landscape. So I had a PNG heightmap, imported it into Unreal, and trying to get it to sit seamlessly on the Cesium terrain was a nightmare. Spent days sculpting around the edges just to make it look flush. Still didn’t look perfect.
This year, same requirement came up again. Seamless landscape on Cesium. And I thought — alright, it’s time to just automate this.
So instead of spending days sculpting again, I sat down and built a tool to do it for me.
The idea was simple — Cesium always streams the highest LOD right in front of the camera, so I just sample the terrain at that highest LOD and warp the Unreal Landscape to match it down to the vertex level. No more eyeballing altitude. No more nudging vertices one by one at the border hoping it looks close enough.
Right now the tool conforms directly to the Cesium terrain. Custom heightmap support isn’t in yet — that’s the next feature I’m working on. The idea is to let you bring in your own higher resolution, more accurate terrain data and blend it with the Cesium surface. A lot of users have better data than what Cesium streams, so it makes sense to support that properly.
Then there’s the Z-fighting underneath. Once your landscape sits on top, the Cesium tiles are still rendering below it. So the tool auto-generates a Cartographic Polygon and Raster Overlay to mask them out — no manual placement needed.
And if you’ve ever tried to delete a Cesium raster overlay mid-session — you know it crashes. Hard. So I built a safe teardown path for that too.
The whole thing is one Actor you drop in the level. Assign your landscape, assign your tileset, click conform. That’s it.
I called it GeoLandscape Conformer. It’s on Fab now — link below. Built it for myself first, but figured others are hitting the same wall.
