Programmers may define a line set as an array of polylines to accelerate hit-testing, pathfinding

https://source-wiki.win/index.php/How_HVAC_Line_Set_Design_Affects_System_Efficiency

Programmers may define a line set as an array of polylines to accelerate hit-testing, pathfinding, and collision detection, using spatial indices to swiftly query segments in large interactive scenes.