Great work Javier! Beautiful picture; wish Lara wore this in Coastal Thailand in Underworld. Love the merging of the 2 layers to create a composite. Photoshop drop-shadow really marry the two pix together! (That's how I do it, maybe you did it differently?) Fair Play!
No not nodes lol. Its very simple. all you do is have a white plan and uberenviroment on with a cast shadow raytrace light on and render the character with pose and all and then you do that same render again but with no lighting or background so it only the character and in photoshop all your doing is using th the png file of the character that has nothing you trace over them and you use that as a seperartor. As in you have the ground only show shadows and not the white.