The sand shader was made on UE4 with the Material Editor.
The few vegetation elements are atlas textures produced on 3DSMax with a classical wind shader in UE4.
The rocks had their basemeshs done on 3DSMax and then were slightly retouched on ZBrush. Some were produced on Houdini at the same time as the structure in the background.
xNormal was used to generate some useful map textures for the shader.