A variety of samples are available at developer.xamarin.com/workbooks.
Some highlights from these samples are listed below:
A series of workbooks that explain how OpenGL works, based on this open source wiki.
Physics and collision detection in UrhoSharp, by Xamarin University
The video covers the creation of a simple 3D scene, shows how to assign physical aspects to objects and how to visualize them, using these UrhoTest workbooks. It also explains the techniques required to detect collisions between objects and how to run asynchronous animations.
Learn the basics of
View property animation in Xamarin.Android.