I need to create a "fake" 3D effect for some raster image, like this one below:
do you know how I can achieve this in Photoshop (CS5) or Illustrator? Thanks.
You can do this in Photoshop CS 5 (Extended) but somewhat painfully. However, if you have Photoshop CS 6 Extended it is now even easier to do this with Photoshop's updated 3D tools and user experience. Additionally, as it is in true 3D space all of the perspective is controlled by a virtual camera, which you can adjust like Field of View and Depth of Field.
Among the other benefits of it being in 3D, the scene is lit with and IBL and/or 3D Lights which can be picked up in the objects materials (Shine, Reflection), and all of your floating elements (3D objects) cast and receive shadows, which you can also control.
Best part is... it's non-destructive! You can go in at any time and change any of the elements positions, replace materials or Texture Maps (images) or even adjust the camera's Depth of Field for some cool effects and much more.
Here's my super quick example for you:
...and my Photoshop 3D workspace:
...and one I did with the 3D camera's Depth of Field settings. (Note that I only let it go for 5 passes, the longer it renders the more noise it cleans up.):
You get the idea. If you like the answer, +1 it, check it, leave a comment or do nothing at all but leave knowing another trick in Photoshop. (^_^)
You can get more information at Photoshop.com. Cheers!
Disclaimer: I am the editor-in-chief of Photoshop Dimensions.