zlacker

Surprisingly enough all of the above is fairly well solved (or at least has the illusion to have been solved) in HoloLens and it turns out that not being able to draw black isn't a huge issue because AR is designed to interface with existing world and all virtual objects are ok to have grey instead of full black. If you were going to watch movie or play classic games, this would be an issue but that is not interfacing with the existing world and AR is not targetted for those use cases.

>>sytelu+(OP)
It's worth reading the article. "How do you draw black?" is a teaser for a much more insightful and nuanced (and convincing) treatment.

Here's a bit more:

Given additive blending, there’s no way to darken real pixels even the slightest bit. That means that there’s no way to put virtual shadows on real surfaces. Moreover, if a virtual blue pixel happens to be in front of a real green “pixel,” the resulting pixel will be cyan, but if it’s in front of a real red “pixel,” the resulting pixel will be purple. This means that the range of colors it’s possible to make appear at a given pixel is at the mercy of what that pixel happens to be overlaying in the real world, and will vary as the glasses move.

>>mumble+h5
I'm not sure that this isn't solvable, having used a hololens, I don't remember this being an issue, and if it was, it wasn't one that impacted my experience.