How do I reduce tesselation effect with textures? I need a few urban and environmental textures (concrete, stone, bark, dirt, ...) and I plan to create them myself. After I make the textures how can I place them on large objects in Blender to preserve high resolution but still reduce the repetitive effect in the resulting renders?
It's in the creation and size of the texture that determines the quality of "tiling" over large objects. There are many ways to create a texture. You seem to be interested in photographic textures. The key to success here is to have flat even lighting and a camera that is perpendicular to the subject. If you want to optimize the result the camera should be stationary (IE a tripod). High resolution is also important in the original capture.

In the texture itself, for 3D rendering, the “Power of Two” is important. One potential reference http://www.katsbits.com/tutorials/textures/make-better-textures-correct-size-and-power-of-two.php there are many others. The Blender default is 1024 x 1024. I use 2048 x 2048. I believe larger file sizes (in the current environment) offer little advantage and can even slow the system down. There can always be exceptions.

*Depending on the pattern of the original image capture/texture some modification most likely will be necessary to facilitate tiling. Every image/ texture is different but here are some bullet points to follow in creating tillable textures (assuming the above).


Remove from the original image capture any “stand out” features (Like a large blemish on a slab of concrete or maybe a knot in tree bark).
Duplicate the image and scale the height -100% and the erase/delete part of the top or bottom. Flatten.
Repeat the previous for the width.
Use the new texture and make adjustments if necessary.


*The use/knowledge of image editors like Photoshop/Gimp is key here.  But this is not the forum for me go into that level of detail. Hope this was of some help. Maybe I should do a tutorial?