...but I would like the final result to be a "3d"-like photo quality portrait
of the person.
How would this differ from what you could get from a single well-lit photo of the person? By "3D" are you indicating that you want to produce a stereoscopic picture? Can you explain in more detail what it is that you want?
-- Burton --
Can you explain in more detail what it is that you want?
Or show us an example?
<http://features.engadget.com/entry/1253716493759137/>
that should get you started.
<http://www.lib.uconn.edu/about/exhibits/seydel/seydelworks.htm>
HOWEVER, I want the final product to be a serious portrait not the odd stuff this guy is doing. I expect that I will be taking the composite (i.e. two or more portraits superimposed over each other) and then manipulating the image almost completely with new color, texture, etc. to create a new image, using the composite as a foundation, which I would like to be close to photographic in quality. And, yes, with colors that POP. Can I do it with photoshop, or any other Adobe product?
such as is created by high quality computer animation
This was not created by high quality computer animation. This was created by skilled artists who happened to use computers. High quality computer animation does not look like computer animation. Get your analogies in line so that we can better understand your intent.
<http://www.lib.uconn.edu/about/exhibits/seydel/sey04.htm>
These two are similar to what I want to do. I also want to go further by enhancing the colors, further manipulation of the shadows, highlights, textures, etc. Can this type of composite be done with Photoshop?
and yes, as mike says it CAN be done in photoshop, but it's not easy. you have to know your way around the interface for starters and then you need to have the artists eye and hands.
Yes, Photoshop is ideal for this. I used to teach photo-cubism projects to introduce layer masking techniques. You can read the 2-3 pages in the manual about layer masks and pull these cubist portraits off quite easily.
The only way that you can see this as 'the appearance of lifelike depth' is if you are Pablo Picasso or on drugs. ;)
The other alternative doesn't seem worth considering.
So, I guess the best thing to do is to learn how to use layers. It's easy peasy when the skills are gained
Selecting from one source and incorporating it into another is a doddle too.
In all of this there is one and only one major pitfall (make sure to respect copyright of any images you did not create yourself)