All Case Studies

2D A* Pathfinding System

February, 2024

This 2D A* pathfinding system in Unity features grid-based visualization, animated path rendering, and dynamic obstacle handling. The project demonstrates real-time pathfinding logic with adjustable parameters, offering a practical approach to understanding the algorithm.

Introduction

• Overview: This project demonstrates a basic 2D implementation of the A* pathfinding algorithm, visualized with a grid-based UI in Unity.
• Motivation: My goal was to gain a deeper understanding of the A* algorithm by implementing it in a system that could visualize its real-time behavior in response to different parameters. This approach allowed me to explore the algorithm from both a coding perspective and a conceptual one, observing how it adapts and responds to various conditions.

Key Features

• A* Pathfinding Algorithm: The system calculates the shortest path between two points while avoiding obstacles. It evaluates possible paths, factoring in movement costs to choose the most efficient route.
• Grid-Based UI: The algorithm operates on a grid where tiles are marked as walkable or non-walkable, with each tile potentially having a unique movement cost.
• Animated Path Visualization: The path is animated by drawing one path point at a time.
• Real-Time Adaptability: The system continuously evaluates changes in the grid, updating paths based on tile states and costs.

Key Challenges & Solutions

1. Writing the A* Algorithm in C#

• Challenge: Translating A* pseudo-code into Unity C# required a deep understanding of its flow, variables, and logic to ensure accurate pathfinding.
• Solution: Broke down the A* algorithm into logical steps and implemented it iteratively, using debugging to verify correct path calculations at each stage. This method ensured a robust, bug-free system capable of dynamically responding to grid changes.

2. Path Visualization

• Challenge: Creating dynamic, animated path visualization.
• Solution: Used Unity’s LineRenderer with a coroutine to animate the path-drawing process, iteratively rendering the path one vector point at a time for a step-by-step effect.

Future Development

Potential enhancements include:

• 3D Adaptation: Expanding this implementation to handle 3D environments.
• Advanced Obstacles: Adding features like moving obstacles or other external variables affecting the pathfinding logic.
• Improved UI: Further refining the grid UI for better visual clarity.

Key Takeaways

Although simple in appearance, this project provided deep insights into A* pathfinding, particularly the logic and structure behind it, as I translated the pseudo-algorithm into Unity C#. Building a custom grid system and visualizing the algorithm’s progress with adjustable parameters gave me hands-on experience with the its practical application and adaptability.