wow I never new this could be useful thanks for the tutorial!
i explained that as well as i could, so i hoped that helped!
thats how the tmp will determin the direction of the pipe
basically tmp 524288 (green) will dump its contents to tmp 786432 (blue), and that will dump to tmp 262144 (red). If all the tmps are the same, it will just flow in random directions. If a pixel of pipe doesnt have a tmp of one of those 3, it will convert back to the unformed pipe.
the tmp also determins what the color will be
yeah so in pipes, any material will be given random movement, to make it look better, and movement in the direction of the pipe (which is determined by the pipe's tmp). So if the tmp of the pipe is all the some, it will only have the random movement, causing whatever you put in the pipe to act like a gas and not really flow in one set direction.
ah so thats why when you copy pipes it works like that