I just tried it and there appears to be no way to accomplish it. I think the 3D pdf only uses the features, not the graphics.
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If you have adobe Acrobat standard (or X pro) installed then when you save your drawing, you can write it out as .pdf and it will work. Also, sketch pictures will work when writing out .pdf's even without acrobat installed. If you do a lot of drawings, then it is worth the price to purchase acrobat for this and many other reasons.