Help rigging a book to open

Help rigging a book to open

I have modeled a book which I want to be able to easily pose in various states (and maybe later use in an animation).

Right now I am only trying to figure out how to be able to open and close the cover (the pages will obviously be a separate challenge).

I assume the best way to do this is with joint tags? This is my first time trying to do any rigging with those tools and after several hours of experimentation & failure, I would like to know if someone can give me guidance.

Sample file attached.

Thanks!

"Search"
is your friend: http://www.cheetah3d.com/forum/showpost.php?p=29410&postcount=10

Cheers
Frank

Ok Frank - I've looked that over a bit now but I'm still not sure how to actually set it up.

My model is in the closed state. So do I add joints in a "U" formation as shown in the screen shot from the linked post?

And do I center the joints on the inside portion of the model?

Thanks.

I see now how that might work - still fussing with it but I get the point now after setting up the U joint.

I'm not having too much luck with this. I tried the U frame joint - pretty much a mess. If I swung the joint to open the book cover too much,, the binding section got all all distorted.

I finally got a clean opening swing by removing a lot of vertex weighting for that joint. But now how do I set this up so that the binding folds over neatly when the cover opens? Morph tag did not seem to help any.

Got it!

Seems the trick was to move the joints into the middle of the book (between the covers) and ensure no other joint but the one I was moving had a zero weight vertex.

One last detail, though. I need to shift the binder down to form more of a curve. How can I do that?

I tried another rigging+binding.
When "heat-binding" is used the joints have to be inside the mesh. So "Distance-binding" works just fine.
Hit "play" when you opened my file.

Cheers
Frank

Frank that method worked out perfectly for me - thanks. With the two independent joint controls for each cover, it allows me to open and position the model for any still composition I need.

But that method still doesn't really work for an animation where the book is laying down flat and only the front cover animates open. Some kind of control is still needed to manipulate the binding to have it turn 90 degrees as well.

Think I solved that last issue. I just added another joint (vertically) along the spine. That will rotate the spin 90 degrees. Combining that with the the other joint that opens the cover and you now have a fully flexible rigged book.

Sample file attached, though I think my set up is still a bit messy. I used heat binding for the vertical joint that controls the spine. The other joints use distance as in your sample file. Not sure what the difference between the two is.

(sample file is animated)

oops - seems to be a problem with my implementation or the rigging. When the book opens, the right (back cover) is longer then the front cover.