Pre-multiply a rotation to this matrix by rotating the given amount of radians.
<p>
If <code>M</code> is <code>this</code> matrix and <code>R</code> the rotation matrix,
then the new matrix will be <code>R * M</code>. So when transforming a
vector <code>v</code> with the new matrix by using <code>R * M * v</code>, the
rotation will be applied last!
<p>
In order to set the matrix to a rotation matrix without pre-multiplying the rotation
transformation, use {@link #rotation(double) rotation()}.
<p>
Reference: <a href="http://en.wikipedia.org/wiki/Rotation_matrix#Rotation_matrix_from_axis_and_angle">http://en.wikipedia.org</a>
@see #rotation(double)
@param ang
the angle in radians to rotate
@return this
Pre-multiply a rotation to this matrix by rotating the given amount of radians. <p> If <code>M</code> is <code>this</code> matrix and <code>R</code> the rotation matrix, then the new matrix will be <code>R * M</code>. So when transforming a vector <code>v</code> with the new matrix by using <code>R * M * v</code>, the rotation will be applied last! <p> In order to set the matrix to a rotation matrix without pre-multiplying the rotation transformation, use {@link #rotation(double) rotation()}. <p> Reference: <a href="http://en.wikipedia.org/wiki/Rotation_matrix#Rotation_matrix_from_axis_and_angle">http://en.wikipedia.org</a>
@see #rotation(double)
@param ang the angle in radians to rotate @return this