I do a lot of this kind of work at Burke. Clients like to see future playgrounds superimposed onto a photos of the site. There's noting better to see how a new playground will look. I have to match the lighting and camera angle of the photo. Often I have to paint out existing playground equipment in Photoshop. The Photoshop preparation usually takes more time than the 3D work.

In a perfect world I'd have measurements of the site, the location and settings of the camera, and the date/time to match up the sun light and shadows. But... our sales reps don't have time for that kind of prep work, so I have to wing it. Sometimes I get lucky and there's a doorway or something with a standardized size I can base a guess on. But most times there is nothing to go on.

Original photo to the left. The finished render below.