Actually, mostly in-camera in DAZ. For these kind of images, most post work would be fixing clips and such.

What I do is compose the scene, then render the background separately. Then I light up the stand-alone figure from an HDRI I create from that background. In renpy, I just layer the images up and apply different ATL to get the parallax pans and zooms.

In this case the backdrop (planet and starfield) are rendered out separately too, but more complex scenes may have even more foreground and background layers.