Hello! I'm creating a terrain/heightmap editor and am wondering what the typical "Smooth Terrain" tools algorithm would be. I'm currently using the Box Filter algorithm (take the surrounding heightmap pixels and average them together to get a final height). But this doesn't produce satisfying results, nor does it look like what Unity3d's terrain smoothing tool produces (Unity3d being an example of what I'm looking for). Does anyone have any ideas as to what Unity or other terrain editors use for there smoothing tool? Thank you!