Ask HN: Which of your original ideas was already implemented by someone else?

I did a lot of work on things like stitching aerial photos and generating 3D models of cities in the early 2000s. Then Keyhole/Google Earth came along around 2004 and mooted all of it. Within a few years, Google and Microsoft had achieved all of my vision. All the 3D earth products have now far surpassed my wildest imaginings.

Then I did a lot of thinking and prototyping around grammar-based procedural generation. I'd noticed that all the research on this stopped at simplistic academic models. But I'd realized that all industrial design is intensely grammatical, so why couldn't I easily whip up a 3D model of a toilet or the Pixar lamp with just a sentence? Well, a few years ago a professional architect turned programmer noticed this too, and turned that dull academic research into a sophisticated and expensive Unity asset: http://www.archimatix.com/gallery

I worked on a GPU accelerated OS shell in 2003, before Vista did it. Mine was actually 3D though, which never caught on.

I'm working on a thing right now that I believe will be ubiquitous in games and especially VR. I've scoured the web and haven't found a single word written about it. It's sufficiently ahead of its time that although I have a very clear understanding of it, and have no trouble saying a lot of words about it, it's very hard to communicate the value to others. And no I'm not telling what it is, unless you're an angel investor :D

I came up with the idea of combining roof shingles with solar panels back in 2012. Now here we are in 2018 and Tesla is making it happen.

Once I had the idea to hide information inside images using the least significant bit, all made sense in my head, got home a searched for something similar and discovered it was a well-known steganography technique.

I had an idea to use the gmail API to create reminders based on a user's inbox. Google implemented it before I attempted it.