title: Find coordinates of point in another coordinate system
body: <p>I've been wrestling with this very simple problem for a long time but I can't seem to understand how to go about it.</p>
  
  <p>I have 2 coordinate systems. Each is different than the other in terms of point of origin, scale, rotation. I have to find the x,y,z coordinates of any random point on any of the coordinate systems on the other. Essentially a change of basis. The coordinate systems are built like so:</p>
  
  <pre><code>glm::mat4 matA = glm::mat4(); //Build matrix with identity
  matA = matA*rotationA;     //Rotate
  matA = matA*translationA;  //Translate
  
  
  glm::mat4 matB = glm::mat4(); //Build matrix with identity
  matB = matB*rotationB;     //Rotate
  matB = matB*translationB;  //Translate
  
  vec3 pointOnMatA = vec3( 5, 5, 5 );
  //Find this point but on the matrixB coordinate system
  vec3 pointOnMatB = ???
  </code></pre>