For a project I'm working on, I need to be able to seamlessly loop tiles side by side. I've read threads on drawing a tile or something of a certain size, then using the offset filter, but what I'm wondering is - is there anyway to draw within a certain bounding box for the tile, and have that same tile updated and drawn realtime next to the tile you're currently drawing? I'm sorry if this sounds confusing (I'm horrible at explaining), but my project is a 2D platformer game, and say we have a block of grass that's 128x64. I need the left and right borders of this tile to blend so that I can place multiple tiles of this kind next to each other and they'll loop nicely, but it's extremely difficult to draw a tile, and then copy and paste it next to the tile every single time I make any change to the original tile to test and see if it'll blend seamlessly as it loops.
Any help would be greatly appreciated, thanks!
Not quite real-time, but you could create a tiled array of Smart Object instances and repeatedly update them by pressing Cmd/Ctrl+S while painting an opened SO in an adjacent document window. However, there's no way to have your brush strokes automatically wrap from one edge to the opposite edge of the tile being painted, so the process is extremely frustrating in Photoshop.
you may want to look at Illustrator CS6, it just added tiling, which you can see live. I have not tried it with a raster image yet, but in theory it would seem to work, now if the programmers think the way I do, who knows. LOL.
In PShop Extended, try using 3D > New Tiled Painting. This will duplicate your brush strokes into nine by nine grid, which you could then crop.