   Camera matrix Question
  Hi Friends,I am a self learner. I don't know not much people to ask for a help. So Posting here..)I did a camera system in opengl and working fine.. user can rotate the scene around all axis and can move through world.So after completing this , i played some computer games. that caused me to think again more about my camera.The problem is scenario is this .In my world user can rotate camera around x axis and can see the up and down part. ok fine. so after this if he rotate the camera in y axis the world rotates , but the x' rotation does not reflects in the y rotation. so the total effect is gradually the x rotation (up/down) results to zero after rotating 90.I know this happens , because i am rotating camera around the rotated y axis. may be i can correct it like every time first rotate in y , then rotate in X and Z ( again here which is first X or Z) ?.I need a common solution.all thoughts are welcome. Please tell me if you are unclear.   