From the grandparent article:<p>> Well, for 40 bouncing circles, on a 700x500 grid, that would be on the order of 14 million operations. If we want to have a nice smooth 60fps animation, that would be 840 million operations per second. JavaScript engines may be fast nowadays, but not that fast.<p>The math is super-cool, and efficiency is important for finding isosurfaces in higher dimensions, but those aren't really scary numbers for normal programs. Just tinting the screen at 2880x1800 is ~2 million operations per frame. GPUs can handle it.<p>A simple way to render is to draw a quad for the metaball, using the metaball kernel function in the fragment shader. Use additive blending while rendering to a texture for the first pass, then render the texture to screen with thresholding for the second pass. The end result is per-pixel sampling of the isosurface.<p>Admittedly, it's kind of a brute-force solution, but even the integrated GPU on my laptop can render thousands of metaballs like that at HiDPI resolutions.<p>(Specifically, I use a Gaussian kernel for my metaballs. It requires exp, which is more expensive computationally than a few multiplies. I render 1500 of them at 2880x1671 at 5ms per frame on an Intel Iris Pro [Haswell].)<p>Though, the work scales with fragment count, so a few large metaballs may be as costly many smaller ones. For large numbers of metaballs, you probably also want to use instancing so you'd need OpenGL ES 3.0 / WebGL 2.0 which are fairly recent.<p>But 40 metaballs with a simple kernel at 700x500? That's easy for a GPU.