Bruce Bilney once did a pretty good tessellation of chess knights. Bruce proudly showed it to the original webmaster of Tessellations.org, Dr. David, back when Dr. David was still alive and I was the Doctor's assistant webmaster. Around the same time, I created another chess knight tessellation which at first glance looks a bit like Bruce's. Here-- judge for yourself.
Bruce has had a few hard experiences with people "borrowing" (pirating) some of his best tessellation patterns without so much as a thank-you from the thieves, nor having anyone properly giving him credit for his invention. See some examples here. So, when he saw that a friend-of-a-friend (that'd be me) did a piece that at first glance looked a bit like his... well, he wrote a mighty angry letter to me. That was enough to make me (stupidly, since calm thoughtful objective communication fixes this kind of problem) not want to talk to Bruce 'til we'd both cooled down a bit years later. Now we recognize that the designs aren't very similar, but our personalities and interests are... and we regret having missed out on years when we could have been enjoying one anothers' gab and insights about our favorite subject, tessellation art. Live...and learn....live...and learn.
You can see much more of Bruce Bilney's tessellation art at his website, Ozzigami.com.au