article with details: <a href="https://tympanus.net/codrops/2019/10/01/simulating-depth-of-field-with-particles-using-the-blurry-library/" rel="nofollow">https://tympanus.net/codrops/2019/10/01/simulating-depth-of-...</a> (linked from the page itself, but I suspect that might not load well on some devices)