Animated Maze Solver August 2025
Visualizing maze generation and solving algorithms as a particle-system animation.
Most people's first (and only) encounter with matplotlib is a line chart in a
Jupyter notebook. I wanted to see how far it could actually be pushed, so I set
out to turn maze generation and pathfinding into a proper animated video, not
just a static plot.
The final script renders a high-quality MP4 in two acts: first, Wilson's algorithm carves the maze out of raw grid space, one loop-erased random walk at a time, visualized as a swarm of orange particles eating through walls. Then Dijkstra's algorithm floods outward from the start in cyan, searching for the exit, before the final path lights up in a single bright red line.
Making a plotting library do things it wasn't built for
The whole animation is generated frame-by-frame - hundreds of individual
matplotlib frames stitched into video. That alone creates a performance
problem: naively, every particle you've ever drawn stays on screen and in memory
forever, and the render grinds to a halt. The fix was giving each particle a
limited lifetime, so it fades out and gets garbage-collected after a short
window instead of accumulating indefinitely.
To make the visualization actually feel alive rather than just correct, I built
a small particle system on top with trail effects and glowing pulses, and used
Python's colorsys module to generate smooth color gradients that track the
algorithm's progress - e.g., particles shift color based on distance explored
from the start point, so you can see the search frontier expanding in real
time.
What I actually learned
matplotlibis a far more capable rendering engine than its reputation as "the charting library" suggests.- Good visual effects are rarely one big idea - they're a lot of small parameters (particle lifetime, fade curves, color gradients) tuned until it feels right.
- Once you're generating hundreds of video frames, performance planning stops being optional and becomes the main design constraint.