If you use shaders and are smart about GPU data structures you can do it, I have got 5-6 million particles running smoothly (60fps) in my own testing which is just a hacky weekend mash with no optimization, here's a blog post of someone who went into detail on something similar here:

https://dgerrells.com/blog/how-fast-is-javascript-simulating... From the blog post:

> This version can hit 20m particles on on M1 mac at around 20fps on battery life. That is pretty crazy for pure javascript. My desktop can do about 30m at the same fps. I asked a friend who had a 32 core CPU to test it and they hit about 40m which is almost enough to fill five 4k displays.

Having a full engine toolkit at my disposal with mature sytems for geometry, physics, particles, templating etc would make me much more productive than having to write the shaders myself, even if the engine has some overhead.

My comment above was a wish list, I know I'm asking for a lot, but I make scientific visualization software so I like to push at the edge!

If it’s fully on GPU that should be tenable, regardless of browser or not