You need to get your nomenclature right: Do you mean "ABuffer" rendering, or "Multipass" with 1 pass. 1 pass Multipass STILL blurs if you have "soften" on.
Exactly. Because there can be 100,000s of hairs (sometimes millions!), there is also a complicated level of code to only allocate those that could possibly be visible (in frame, in front of other geometry).
Matt. You and your brother have sure been doing good work lately. It's a pleasure to have your inquisitive minds, (you actually research your problems). I hope there's more where you came from.
Niels;
Please ask questions in the context of the exercises of "The Art of Animation:Master" (TaoA:M), the book that comes with the software. This thread is disjointed and premature. How far have you gone in TaoA:M? TaoA:M is set up for newbies. By asking questions out of turn, you only frustrate the people trying to help you. Lot's of folks will jump in to help, as you've seen here.
David;
Write up the steps of how you made "Froggy Boxing," including pictures. Every kid in every school we sell to will make you their hero. (And it will help A:M too.)
Thanks.