Terrain heightmap

Hi, i'm trying to find the best pipeline to create a playable terrain in unity using external softwares like world machine. Actually my only one pipeline is the standard one like "export from world machine in .r16 format than change extension to .raw, then export splatmap and use a unity 3D package which assign 4 to 8 textures into this splatmap" but the result isn't that good. Now i would like to find a new one pipeline, like "export terrain from world machine in .obj format, paint it manually in mudbox so i can assign more effective textures like mesh normal, cavity, AO" and so on, but i'm not sure which is the best pipeline to get realistic terrain and lighter. Anyone using world machine would like to help me?