Yeah, they're seamless. I've just cropped them out of a 512x512 texture.
The only time it's gets confused is when you have a brick size / mortar size that doesn't stack up for the texture size you want. It's still seamless but looks rubbish because you end up with a slither of brick at the bottom or something! Not sure what to do about that?!
The only time it's gets confused is when you have a brick size / mortar size that doesn't stack up for the texture size you want. It's still seamless but looks rubbish because you end up with a slither of brick at the bottom or something! Not sure what to do about that?!