Based on DAY4's homework of my Processing Startup Courses
@ Xinchejian Hackerspace, I modified the code a little bit and turned the 2D environment into 3D. The particles on the screen will form triangles according to the length of three sides. The area of each triangle through Heron Formula
is also taken into account.

The video below, however, is a 2D version, which is combined with some simple physics. Thanks to beads lib
, the real-time version can also play certain note when each particle hits the board. Unfortunately, I still don't know how to record these real-time notes using Processing's native code :(