I'm developing a basic triangle mesh raytracer on a short deadline.
This means I can't implement every feature I come across, so I'm looking for some feedback about which features you think are most important, taking into consideration the performance of the feature and how much punch it packs.

I'm especially looking for optimization techniques that allow for a faster rendering and simple techniques that make a big impact on the final scene quality.
Is there any chance of making it fast enough to run in realtime?

Here are some example of features I've read about:

• Anti-aliasing
• Bounding box
• Sky box