stolenanjel,

The first thing you need to do to make a believable shadow is to identify what is casting shadows, where the shadows are falling and what depth the shadows are.  If you go back to Poser and place a large box with dimensions a bit larger than your wings close behind your character and then render.  You will then be able to see what the shadow pattern will be that needs to be replicated on your pasted wings.  At this point you could follow Ofthepasts suggestion and use the dodge and burn tool to try and replicate the pattern.

 Another option that you might try is to take the new render with the box and add it as a new layer to your main image and then lower the opacity so you can see the wings below.  Match up the characters position of both images and then mask out the wings.   With the box render layer selected press Ctrl+J to make a new layer from your selection and then delete or hide the box render layer.  You will now have a new layer in the shape of the wings with the shadow pattern on it.  If you now change the blending mode of the new shadow layer to multiply you should be getting near to something like an accurate shadow placement and pattern.  Tweaking the new shadow layers opacity and blending mode might bring the shadow layer to a more believable state.  If the edges of your new shadow layer are to harsh just use the eraser tool with a soft brush and a lowered opacity to soften the edges.

Because I don't have your source images I haven't been able to test this method so I am just picturing this approach in my mind so I hope it works.

Shane

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