I try to display elevation data using the triple Geoserver/Openlayer3/Cesium. It seems I have the same problem than https://stackoverflow.com/questions/25936968 and for now, I can not get a working solution!
I have done nearly the same gdal processing to obtain my picture pyramid and whatever the GeoserverTerrainProvider solution I use (BIL or with SLD) I get sharp cut elevation at tile edges (see: http://postimg.org/image/wy0j1ijnp/)
In the geoserver layer preview, my elevation image as bad tile border in 'Tiling: Tiled' mode but is ok in 'Single tile' mode. This may be the cause of my problems: ie. GeoserverTerrainProvider is badly requesting tiles from geoserver?
Or did I fail at generating the pyramid geotiff?