Nature of Code Final Project Proposal

For my nature of code final, I want to make pliable flow fields that a user can manipulate with their hands. My inspiration for this project comes from memories of building castles, moats and other structures out of sand at the beach. The ability to impose a directionality to water by shaping it's surrounding path is something i'd like to replicate. The tools I plan on using for this project are Processing, the Kinect, a projector and twenty-five pounds of white play sand. The idea is that the user will be able to manipulate the positioning of the desired velocity of a continuous flow of water by digging into a box of sand, moving the sand around and playfully seeing how the stream responds to their input. Ideally, the kinect will calculate the depth of the sand and wherever the user digs, the vector stream will elongate, broaden or change direction based on their choices. In essence, the vehicles comprising the stream  will perpetually impose a consistant flow from one edge of the sand to the other.

Dan's flow field following examples are the foundation for this piece. While building my code around this, I casually browsed a few YouTube videos to see what kind of work had been done relevant to my idea. Turns out, I am not the first person to have connected these dots. Nevertheless, I intend to emphasize my own interpretation of these elements in my final project.

Amongst my various logistical concerns, one particular technical/conceptual challenge I am having is figuring out a way to transform the vehicles into something that actually resembles a flowing stream of water. Any insights for how to make this work would be most helpful!