I am having problems importing a Raw file (heightmap) generated in World Machine program, I dont know how to set the correct size or resolution, I already asked in Ue4 forums but no one helped me yet.
you need to adjust the settings on the import page to eliminate the stretched edges. i believes its the number of components or something like that. basically look for areas in the wireframe that looks really flat. as for the hign spikes just adjust the scaling. either scale down the z axis by half or more, or scale the x and y to be huge.