3D Math Primer For Graphics and Game Development (Wordware Game Math Library)
It helped me tremendously when I was into game development back in college. The math was always the biggest hangup for me. I'm in healthcare software now, so YMMV :)
Many KDE styles use SVG and plenty of animation. The user can always change themes. I think you should be more specific about what kind of animations you want to do. I don't think 3D wall type affects really fall into the widget category that QT is. It sounds to me like you want to make a 3D interface for an application. If that is the case, you may want to look more into 3D engine type libraries used mainly in games. I know that some have excellent GUI widgets for programming game menus and the like. I guess you'd decide on your engine and the see if there are python language bindings. One of my favorite engines: http://irrlicht.sourceforge.net/links.html
Another thing you would want to consider is how you want to handle the window management. Do you want to make a full screen interface? Or is to to be windowed? Also how would such an application integrate into a 3D window manager or rather a window manager with compositing.
In that case the qtopengl module is probably something to look into: http://doc.qt.nokia.com/4.6/qtopengl.html
I do recommend QT. It's clean and easy to use and cross platform. So your app could run on windows as well.
One thing you'd want to think about before hand is the type of FX you want to perform. For example, if you want to create a page curl type effect when renaming the image, you'd have to think about how to program that, or look for libraries/code snipets that do that math. 3D engines that are used in games often have a lot of support for those kind of typical FX or animations that you'd see in a game. If you use something like qtopengl, you'd need to think about this as well. qtopengl can pretty much only render. Think of it as a viewport. However, it is the correct approach to making a 3D application for the desktop.
Programming 3D applications is really interesting and fun. I enjoyed it a lot. However, don't get discouraged be the math. I recommend getting a book about it if you are serious. I liked this one: http://www.amazon.com/Primer-Graphics-Development-Wordware-Library/dp/1556229119
However, IIRC the examples are C++ which you may not be comfortable with. When you understand such mathematical concepts, it easier to think about how you would make a page curl type affect. Of course, if you find libraries or code that shows you how to do the math, that may be fine.
I got a lot out of "3D Math Primer for Graphics and Game Development". I know it says 3D but there is a lot of stuff in there for 2D. And the math is fairly simple linear algebra.
What I found very good and I'm still getting back to it from time to time to refresh things up
is 3D Math Primer for Graphics and Game Development. Also regarding calculus and linear algebra I find very good for getting back ones college course memory the resources at Khan Academy... sometimes it puts a nice practical perspective on things and the guy has
has a real talent at making the subjects fun and entertaining.