What is a line...

I started this brief by taking pictures with depth in them. I like that a line can show depth and make a 2D image seem 3D. I've been playing with drawing to try create this effect of depth. From this i want to start looking at what happens from the front to the back of the line. For example if a man was walking along the line he would shrink the further away he gets. This is a very simple example, i could take this much further with line to make things appear as if they are coming closer or moving further away. This could work with a series of drawings made into a flip book or i could make a movie. It would be interesting to explore how i can try make a 2D page become very 3D using line. My work will mainly be drawing but these will be brought into flash or some movie software to play.