Unity中路径点索引越界错误（ArgumentOutOfRangeException）如何解决？

Let's break down why you're hitting this error first: when your object reaches the last waypoint, index increments to equal waypoints.Count (since collection indexes start at 0). The problem is your second if condition still tries to access waypoints[index] at that point—but the collection only goes up to index waypoints.Count - 1, hence the out-of-range error.

Here's how to fix it, with proper support for both looped and non-looped movement:

private void Update() {
    // Exit early if we have no waypoints or index is already out of bounds
    if (waypoints.Count == 0 || index >= waypoints.Count) {
        return;
    }

    // Move towards the current waypoint
    transform.position = Vector3.MoveTowards(transform.position, waypoints[index].position, speed * Time.deltaTime);

    // Check if we've reached the current waypoint (using a precision threshold)
    if (Vector3.Distance(transform.position, waypoints[index].position) < 0.01f) {
        index++;

        // Reset index to start if looping is enabled and we've reached the end
        if (loop && index >= waypoints.Count) {
            index = 0;
        }
    }
}

Key improvements made: #

• Guard clause at the top: Prevents any attempt to access invalid indexes by exiting early if there are no waypoints or we've already reached the end.
• Robust position check: Comparing Vector3 values directly with == can fail due to floating-point precision quirks. Using Vector3.Distance with a small threshold (like 0.01f) makes the "arrived" check far more reliable.
• Proper loop handling: When loop is enabled, we reset the index to 0 once we hit the last waypoint, instead of letting it climb out of bounds.

Also, a quick note for your Start method: if no GameObjects tagged "wp" exist, waypoints will stay empty—this fix handles that case gracefully to avoid crashes.

内容的提问来源于stack exchange，提问作者Daniel Lip