Q:

Creating 3D book cover mockups from scratch

You very often see 3D mockups of books that look realistic enough to pass for a photo of the book at a glance. They’re a great way to make a flat front page come to life, and it’s no wonder they’re frequently used in marketing. Something along the lines of this is what I’m referring to (taken from CoverVault):

Working for a publisher, I would like to somehow incorporate this type of mockup into our marketing strategies, since they are in many ways superior to actual photographs (no glare, and the distortion can be reduced just enough that the book looks like it’s seen from an angle without being all bent out of shape like it gets in a photo).
Googling for tutorials on how to create these things turns out to be surprisingly difficult: a lot of people apparently want them, so there are a million and one websites with free and paid ready-to-use Photoshop templates and plugins. Great. Except they’re all completely and utterly inflexible. You cannot customise the size of the book or the angle the book is seen from or anything else, which makes them essentially useless to me. There are a bunch of actual tutorials I can find as well, but step 1 in all of them seems to be “download a Photoshop book cover mockup from the Internet”, which doesn’t really help me much either, since making the mockup itself is what I’m trying to find a tutorial for.
I’d much rather learn to actually create a flexible shape that I can wrap or distort my artwork around to create a 3D mockup, but being a relative Photoshop rookie (I generally work more with text than graphics), I don’t even know where to begin in doing this.
Does anyone know of any resources for figuring out how to go from having just a flat book cover image to 3D-ifying it into something that looks realistic?
(I don’t have access to, nor much of an inclination to [re-]learn full-blown 3D modelling programs like 3D Studio Max or Blender. That’s too much effort for this one thing.)

A:

I always recommend using a direct 3D application with a photorealistic render engine.
Use Blender. https://www.blender.org/ I am pretty sure that you can learn how to make a book and unwrap it in a couple of hours.
And you just need to replace the source texture for the next book cover, or the texture for the table, the width of the book, the dimensions, lighting, shadow, camera angle, perspective, glossiness, add a mug, ad ambient, and mood...
Real 3D is the way to go.

A:

I believe you want something between ready to use mockup and learning Blender (or equivalent). You can get something in Illustrator and Photoshop altough I admit the result probably is far from a high quality photo and you lose all micro-details of properly rendered 3D textures. The quality can still be enough for web pages.
Illustrator allows 3D extrusions. With it you can extrude the parts separately or as grouped. Here is one grey paper:

Shadows and highlights, perspective (here=none, only isometric view), coloring, texts and even images are possible to add in Illustrator.
Mapping images to extruded surfaces in Illustrator is difficult because Illustrator often divides curved surfaces to pieces which are impossible to see beforehand. That's why I make only a simple body in illustrator and continue in Photoshop. 
Staying in Illustrator gives a benefit: Book dimensions and watching projection are easy to change. If you want to stay in Illustrator, be sure that those areas which will get a mapped image, are extruded from straight lines or extremely simple curves with no anchors in the image area. Here the cover is quite curved.
The simple body:
 
All parts are grouped before extrusion. Unfortunately all parts in Illustrator get the same extrusion depth, if they are extruded as a group. Inner sheets of the book should be shorter than the cover. That can be worked around by extruding the sheets separately and combining all afterwards in Illustrator or Photoshop. It's skipped here. Also a complex binding is skipped.
In Photoshop images and texts can be added. Only distort them to the same projection with Edit > Transform > Scale/Rotate/Skew/Distort.
Light effects are also possible. Here only an elementary shadow is added. 

BTW. This book has only 50 pages, but they are quite thick. They are a bunch of horizontal lines, splitted with quite arbitary curves at the ends.
Book cover can have foldings due the binding. See this older case:
Imitate a photo realistic rendering of a book cover
ADD: To show that the pages of the book can have different length than the cover I inserted this screenshot from Illustrator:

The pages and the cover are extruded separately with different depths (=one extrusion is made, duplicated it, from one copy the pages are deleted in isolation mode, from the other the cover was deleted and the extrusion was shortened)
Pages were raised to top and dragged to the right place. Another copy of the cover was made, raised to top and inserted an opacity mask (or clipping mask) to hide exessive parts of the cover copy, only front cover is left.

