An essential part of any world transformation matrix is rotation. Rotation corresponds to the angular orientation of an object, compared to a particular set of axes.

Ultimately, the rotation of an object is created by using a matrix that is concatenated with the translation and scale matrices to form the final world transform matrix. However, there is more than one way to describe rotation when we construct the rotation matrix.

The method that we use in this tutorial involves a set of intermediate rotations called Euler rotations. Think of the Euler rotations as a set of three different radian angles, from 0 to 2π, each around a different axis. The axes (X, Y, Z), can be thought of as the pitch, yaw, and roll axes.

Pitch, which is measured along the X-axis, can be thought of as orienting the nose of an aircraft up or down. Yaw, measured along the Y-axis, swings the aircraft side to side. Roll, along the Z-axis, can be thought of as the aircraft banking to the left or right.

To use Euler rotations in the XNA Framework to build the rotation component of a world transformation matrix, use the Matrix.CreateFromYawPitchRoll method, passing in the appropriate rotation angles. This forms a single rotation matrix that you can then concatenate with translation and scale matrices to form a final world transformation matrix.