As Gabe Newell, founder and Managing Director of Valve Software explained to us, adding advanced features to a project gets exponentially more complicated the larger the project is. That's why, although Valve originally wanted to bring HDR technology to Half-Life 2, the five-year project could not cope with the additional complexity of adding this feature. The company went through no fewer than four different attempts to integrate full HDR rendering with the Source engine, using a small level to test the look and performance of the new effects each time.