Really easy and quick 3d realtime interactive graphics
The talk in one sentence
Many introductions to graphics programming focus on 2D, which is a bit boring. 3D isn't much harder, particularly if you use Processing.
Generative Design website (of book) with lots of source code. The book is excellent, filled with beautiful examples and clear code snippets, though is quite expensive.
Processing 2: Creative Programming Cookbook: the other book I recommended, it has 3D appearing relatively early.
Android version Again you can do 3D things with this, along with multitouch, camera and other device sensors. You can create APKs and submit to Google Play.
Codea (for iPad) while in Lua, uses a very similar graphics API and allows you to write applications on an iPad which can be exported as an XCode project.