游戏 AI 寻路：从 A* 到 Navigation Mesh

A* 算法核心

f(n) = g(n) + h(n)，其中 g 是已走过的实际代价，h 是启发式估计代价（曼哈顿距离或欧氏距离）。

// A* 核心伪代码
open_list = [start]
while open_list not empty:
    current = node with lowest f in open_list
    if current == goal: return path
    for neighbor in neighbors(current):
        g = current.g + cost(current, neighbor)
        if g < neighbor.g:
            neighbor.parent = current
            neighbor.g = g
            neighbor.f = g + h(neighbor, goal)
            add neighbor to open_list

A* vs NavMesh

A* 适合动态网格（如塔防中实时改变地形），NavMesh 适合复杂三维地形的高效寻路。两者各有优势，可以组合使用。