Particle Trajectory File Format (Simple Text Version)

• The first line of a particle trajectory file specifies the number of particles.
• Each subsequent line describes a single particle.
• A particle line starts with two numbers: the particle's start frame index and end frame index.
• For each frame index in this range (including the start/end frames), the file has a particle point entry.
• When a particle is active in a given frame, the point entry has three numbers: 1, followed by the x coordinate, followed by the y coordinate.
• When a particle is not active in a given frame, the point entry has one number: 0.
• The coordinate system starts in the lower left.