"Yes, if only I knew what "you should not rely on automatic processing to set your saturation and brightness levels" meant, I'd be quids in!"
All Halo was saying is instead of processing the image in realtime, just make grayscale textures to texture the geometry with when you want to put the game in a grayscale mode. And that doing this would give you more control over what the final image looked like, than simply converting the image to greyscale based on how bright each pixel is automatically.
All Halo was saying is instead of processing the image in realtime, just make grayscale textures to texture the geometry with when you want to put the game in a grayscale mode. And that doing this would give you more control over what the final image looked like, than simply converting the image to greyscale based on how bright each pixel is automatically.