[Sohcahtoa82]

> Graphics is trivial until you get to shadows and lighting

And reflections and refractions.

Raster-based reflections are a simple shortcut: Just take the rendered image of what's being reflected and invert it.

But that doesn't work when the reflected object is off screen. As a result, if you're over water that's reflecting a city skyline or something in the distance, then pitch the camera down, the reflection vanishes as the skyline goes off screen.

Alternatively, you can create an environment-mapped texture, but that makes the reflection not reflect what's actually there, just an approximation of it.

I find it incredibly distracting in games. It's like bad kerning: Once you know what it looks like, you see it EVERYWHERE.