In the kingdom of the nerds there is one surefire way to get hits on your BLOG, your youtube channel or whatever nexus serves as the focus of your little roadside turnout on the net, tutorials. There is a booming business in turtorials. They will tell you everything you ever wanted (or didn't want to know) about just about anything you can think of.
The reason I bring this up is that I am working on a project for work and I needed to know a simple way of simulating blood flowing through a vein. We have all seen the kind of animation I am talking about, pillowy little corpuscles sailing placidly through a sea of plasma without a care in the world. Sometimes they bump into each other like fat German business men on the underground...
"WHOOPS!"
"Mein apologies mine freund!"
Simple enough. Then why in the world was it so hard to find a tutorial that told me how to do that?