The Easy Environments series for Daz Studio and Poser combines high-res (12000×6000) SkySpheres/HDRIs with terrain geometry.
The terrain makes sure your character has something to stand on, while the SkySphere/HDRI provides full scene coverage and great vistas.
ExoPlanet III is a planet mostly covered in water, with scattered rocks brushed by rain storms. It`s well suited for scifi or fantasy renders. The rain (as seen on the previews) is part of the set. The prop can be hidden if you want to go for a calmer scene.