title: Same raytracer code returns different results (cmake)
body: <p>For our final assignment, a friend and I are creating a Raytracer in c++. We're working with Github and cmake. Everything was working fine, until we implemented shadows and refractions. These work fine on my friends computer, but not on mine. The shadows don't work at all and the refraction has got a lot of black dots on it. Another weird thing is, that std::couts from the main file don't get displayed in the terminal after executing, but I'm definitely working on the correct file (I still get errors when writing random stuff in it).</p>
  
  <p>Tried pretty much everything from cloning again, copying the files over usb and updating the compiler.</p>
  
  <p>Since we're working with floats I thought it could be a result of floating point inaccuracy, but i guess that wouldn't explain the missing prints...
  Don't really know, which part of the code would be helpful, but i can post any. He's using Ubuntu 15.04 on 64bit and I'm using 14.04 on the same machine. </p>
  
  <p>I hope, somebody can help me here!</p>
  
  <p>Edit: Okay, just tried to print something from an included file, works just fine. But still no print from the main file..</p>