title: Rotate Point3D around Unit Vector
body: <p>as an Image above</p>
  
  <p><img src="https://i.stack.imgur.com/wUVvd.png" alt="enter image description here"></p>
  
  <p>i want to rotate the point <strong>P1</strong> around unit vector <strong>RotationAxis</strong> (Red vector in Image and its in Center). </p>
  
  <p>in my program (WPF) i Have a Quaternion and a 3DPoint.</p>
  
  <p>How can i rotate the Point <strong>P1</strong>?</p>
  
  <p>i tried Matrix rotation but it rotates nothing.</p>
  
  <pre><code>Matrix3D matrix = Matrix3D.Identity;
  matrix.Rotate(RotationAxis); //RotationAxis is Quaternion
  matrix.Transform(point3D); // point3D is Point3D that i want to rotate around RotationAxis
  </code></pre>