You will have noted the 'core content' of Poser 13 comes with two environment scenes as example/template startups. One is a 'wide street' and the other is a beech shot.

For this example I will be using the beech shot, where I met, long time no see but hey you are looking good! Roxy.

Note how the direction of Roxy's shadow matches the shadows of the trees in the background image. This is because the light comes from the sun in the HDR image.  Note also how the shadow is smooth and does not match the ripples in the sand. Too bad but that's how it is. 

Roxy said she was bored with this beach and wanted to change environment.