generating repetitive patterns

[pure]

hi

i want to generate repetitive patterns for cgi artists.
i found out how to do this in photoshop cs5 (my main app) now,
but the difficulty is to generate a pattern which has no seam on all 4 sides.

i asked already a similar question at subforum, they meant i should use the seamless tile plug in, but its useless as the cgi artist needs the pattern as a square tiff image to repeat itself in his 3d-application. so i am working on details now and how to remove the seams in ps with curves (there seems to be always one side which is lighter oder darker, and that is visible when you repeat the pattern 500times on a square image, you always see the same pattern.)

my method is simple: lets say i use the filter "facetteneffekt" to generate digital polygons, i have 20 polygons on a square image, then i add space around the image size and duplicate the polygon pattern, moving it to the right side to see if there are broken seams and fixing them with drawing new lines and erasing wrong ones, i repeat this method another 3 times for all 4 sides of the square image. the seamless tile is finished!
then i use photoshop command "define pattern" and create a new big image where i fill the whole image with my newly defined pattern.

only big problem is, that i always see some parts which are darker, and some which are lighter in the tile, also you can spot struktures which repeat itself clearly, so is there an application or plug in or filter (osx) which could help me?

thanks

[Chain]

Filter > Other > Offset... is my best friend when creating textures that must repeat seamlessly.

It lets me offset ("move") the pattern in Photoshop so I can see if there are any visible seams. They are then easy to fix with e.g. the healing brush or whatever tools fit the task. Removing the seams is usually not a big problem.

If you want to make it less obvious that a texture is repeating it should avoid "defining" features that stand out, even shading, but I would recommend trying to have it repeating fewer times on the 3D surface, using a larger texture, or have several textures blend together in the completed 3D material. We humans are very good at spotting patterns, and a pattern it will have when repeating evenly.

If your problem is that the texture is unevenly lit (e.g. darker on one side) and even if you fix the seam the "low frequency" uneven brightness becomes visible, curves (with a mask) could be used to adjust brightness, but a band stop/frequency separation could also be useful.

If you have an example of a specific texture that gives you problems, it would be nice if you could post it. Makes it way easier to answer.

[pure]

thanks, i understand, chain.

what i wonder about the offset filter:
isnt it the same effect it creates, when i copy and paste the pattern 4 times (each on a separate layer) and place/move it manually by hand on each 4 sides of the main pattern, then i also see where the seams are and can healbrush the seams.
thats how i created my seamless tiles so far..as the offset filter has no preview and i have to do apple-z and go into offset filter a dozens of times, when i create the wrong offset (i guess i dont understand the offset filter, as i always create the wrong offset

i guess about buying the pro version of "filter forge"
as there may be a comfortable filter for creating seamless tiles with preview and so on... maybe tried yourself?
http://www.filterforge.com

nothing against the offset filter, its just a bit uncomfortable and not
improved for years. (no preview etc.) especially when you want to create about 50 hires and wonderful seamless tiles in 4 days, lets say..

regarding your example, i like it!
one question:
the starting point tile, is this tile already seamless or with visible seams?
is there maybe a video tutorial which describes every little step?
i found some, but they leave out important things...

[Chain]

The Offset filter shows the result live in your document.
Way, way, way quicker than copying your merged document 4 times and manually shifting them.
You could automate your method using actions, but I don't see the need.

Also, in the world of 3D textures you probably have a fixed texture size like 1024px, so you could then go 512px to shift it 50%. Again, no guessing.

--

A filter can only do so much. You should clean up the seams by hand, I doubt you can find a filter that would do that for you (at least in a good way)... It depends a lot on the texture you are making.

My example was just shingles form a random picture on the web. Visible seams (see the 2nd picture - the seams go through the middle as the offset was roughly 50%).

--

Did you have an example texture that is a problem?

[lkroll]

The offset heal/clone technique is the manual method, but I also like using filters for some textures (lazy guy I am). Simple's filters are pretty cool for certain type of textures. GIMP's Resynthesizer filter also is nice for helping with healing the seams. As you progress in creating seamless textures, you'll pick up both tools and techniques to help you do this. Creating seamless textures is a side hobby of mine.

Yes; this link's a SSP (shameless self-promotion). lol

Feel free to use any textures that I've concocted.

http://lylejk.deviantart.com/gallery/