Thank you for this codepen! it certainly helps. I am trying to find a way to add a background image to the .dot class. Is this possible? I'd like to replace the particles with leaves for example. Simply adding a 'background-image: url('http://example/leaf.png');' does not seem to work. I tried adding it to the js as well into this line of the codepen code but couldn't figure out anything that works:
initialVars = {css:{borderRadius:"50%", width:100, z:0.1}, immediateRender:true}
Any advice (clearly, I'm a newbie at this)?