I am currently trying to design a seamless tessellating pattern for a client using an impossible triangle I drew. I figured out how I want my shapes to tesselate but having mapped out the first few stages by hand far enough to know that it works, I am now totally stumped as to how I can now turn this into a seamless pattern that will repeat for ever. I have quite a bit of experience in creating seamless patterns on photoshop and illustrator but not normally anything this precise / mathematically complex. Having tried both programs I am still no where close. Can anyone out there tell me what I am doing wrong and how to turn this into a proper pattern?? Many many thanks in advance! Ross

I don't do many pattern repeats but as I understand them, to be seamless they need to join up where the other left off. I do know that from working with odd sided, geometric shapes (3, 5 and so on) they start to get a bit awkward and the Pentrose triangle makes things even more complicated. I understand that 'where there's a will, there's a way" and I hate to be beaten by a design but when dealing with the laws of geometry it might just not work and you might just be on to a non-starter. PS and AI use square tiles and triangles and squares don't like each other very much.

Hi Scotty, thanks for your reply. You took the words out my mouth, I know it must technically be possible and as such i hate to have to give up on it but theres only so long I can spend trying to make it work and I think I have done so long enough already. Perhaps its just not possible using the algorithms that the programs have in place. Yes indeed, the sides of the tiles must match up but that is impossible in this case since the row becomes slightly higher each time. Think I may have to hit the drawing board again with this one! Ross

I think it will be possible, somehow but with the restrictions that AI and PS have in place for pattern repeats may make you need to compromise a lot. With the pattern stepping up each time, it may make you have to reduce it so that the row below steps back into place (horizontally) but then there's the vertical to think about as well. Sounds like a real headache to me an the kind of thing that I always get wrapped up in.

Essentially you need to find a vertical and horizontal point where the shape returns to its original position. If you look where I've put guides, you're about there on the vertical guide but theres a long way to go on the horizontal one before the triangle has stepped up enough to sit on that guide again.

@bigdave Nice One.... Question for @Blacklava ...why are you doing this in Photoshop. I think Illustrator would be a much better option.