SketchUp has texture editing tools that make it easy to crop and edit textures. This feature can help you to create seamless textures, and there are several cases where you may want to do so:
- Creating a repeating texture for a Google Earth model to remove occluding objects like trees and cars.
- Creating a repeating texture to reduce the file size.
- Creating a seamless texture of a repeating pattern such as a brick, stone, or carpet.
In the first two instances, you'll probably want to start within SketchUp. Import your image as a texture (File > Import > [Image Type] > Use as texture). Context click on the texture and select Texture > Edit texture image to open your texture with your default image editor. Depending on the image editor, you can offset the image to the center, then use a heal tool to cover the seams. If you're using Photoshop, check out the Seamless Tiles Tutorial (English Only) from CadTutor.