Tessellation but in reverse

i am new to unreal and i am trying to add scan data of a lage area of ground but the poly count is too high
is there some way i can have something like tessellation but in reverse so far away things become “simplified” WITH OUT USEING LOD!!! a lod would swap out the entire ground including the close things
the mesh also has complex overhangs and things so a height map will not work as is too much to manually remesh and would simply take too long and auto things will give errors because of reasons in the close up things

so to sum up i just need a reverse tessellation that decimates the far away mesh even if the silhouette and the uv gets messed up

There isn’t anything in UE4 that can do that, you would have to split up the mesh so that you have more control over what parts get swapped out for lower-quality versions

@Darthviper107 is not entirely correct. relevant documentation

wait, i just read your actual post instead of just skimming it. surely… landscapes? are what you’re after? why are you not using landscapes?

Take your mesh to your external 3D package of choice, divide into foreground/background. Use a poly reduce type function to simplify background mesh. Then bring the meshes back to UE4.

He wants to do it in real-time on portions of a mesh, which isn’t possible.

o i see.

What about: just make the mesh in to smaller LOD sections in such a way so that they line up with the high-res versions?
Like this:

That way you can keep the detail for the high-res close up shots, but the mesh is broken up in such a way so as you allow for farther parts of the mesh to be lower-res without creating gaps between the sections.