Working on a Digital Pop-Up Book for an Establishing Shot

I am hoping the Procedural Animation Class I am taking will be useful to make a Digital Pop-Up book that I can use to make an establishing shot.

Cover

The cover is a box with a divide. The inside points are grouped and the size is increased with a transform. The height and width are controlled by the scaling of the pages [ch("../PageScale/sx")*1.01], but the y axis is another slider to independently adjust the thickness of the cover. Shere is an adjustment to the translation to compensate for the shear of the pages [((ch("../Rotation_Pivot/rz")/-90) *+0.0184) -.02] and a negative shear, that was intended to be a subtle deformation as the book opens, but it has not been developed yet.

Pages

The pages are a box with a shear a soft transform to curve the shear and a soft transform to swell the pages as the book opens.

The Shear distortion is a combination of shear with a strength manipulated bu the angle of the book [((ch("../Rotation_Pivot/rz")/-90) -1) *-0.4], and a soft transform translating on the roatation of the book [(ch("../Rotation_Pivot/rz") + 90) *-0.0005]

The bulge is controlled by a slider to simulate the stiffness of the pages and the angle of the book. Y axis translation of the soft transform used the following function: ((ch("../Rotation_Pivot/rz") /90) - 1 *-1) * (.6 - (0.06*(ch("../Stiffy/scale"))))

Bothe the cover and pages are mirrored on the YZ axis with a pivot at the top corner of the pages.

Spine

The spine has been a problem. I intended the number of pages to be adjustable, but the shear changes the X and Y coordinates of the edge of the cover that intersects the spine, and the value of this offset changes as the book gets thicker.  

The without the shear distortion the Y coordinate of the intersection is (cos( ch("../Rotation_Pivot/rz") and the X is (sin( ch("../Rotation_Pivot/rz"). I added a fit as a fudge factor [it(-ch("../Rotation_Pivot/rz"), 0, 90, -90, 0)], but the values change as the book gets thicker, and I have not figured out how to compensate for the variable. As a result, increasing the number of pages causes the spine to detatch from the edges.