Suggestions for WebGL library - simple 3D scatter plot

I’ve been poking around (Three.js, etc) and haven’t found exactly what I’m looking for. I just want a simple three axis coordinate system (x,y,z) on which I will calculate the vectors of the various leads of the electrocardiogram (EKG) leads into a single point (or arrow) on this 3D coordinate plane that I can update with javascript in near real-time from the raw output of an EKG machine (MUSE system for those interested.) I know there are those on /r/javascript much smarter/more experienced in WebGL than I; I don’t need any complex textures or crazy shapes made out of triangles, and I haven’t found any very simple examples of just a 3D scatter plot where I can plot my point/arrow. Your help is very much appreciated!