如何在SpriteKit中创建随机生成的物理赛道？

Hey there! Let's walk through implementing that procedural track generation system you need for your racing game. Since you only want to focus on the track spawning logic (with physics bodies, leftward scrolling, random right-side segments, and edge collision game over), here's a practical, actionable breakdown:

First, model each piece of track as a reusable physics-enabled segment. Each segment should include:

• A polygon collider (or appropriate shape) that acts as the physics body for both the road surface and its edges.
• Visual assets matching its shape (straight, gentle left curve, sharp left curve, gentle right curve, sharp right curve—align with your sketch).
• A "spawn marker" on its right edge—this is where the next segment will attach to keep the track connected seamlessly.

To create the illusion of the track moving left:

• Instead of moving the player right, translate all active track segments left at a consistent speed (match your game's desired movement pace).
• Add an off-screen position check or trigger collider to the left: when a segment fully exits the viewport, destroy it (or add it to an object pool for reuse—way better for performance!).

When the rightmost segment's spawn marker reaches the right edge of the screen, generate a new random segment:

• Create a list of possible segment types (adjust the mix based on how often you want curves vs straights).
• Use a random number generator to pick a segment type from the list—you can even add weighted randomness if you want more straights than sharp curves.
• Spawn the new segment so its left edge aligns perfectly with the rightmost segment's spawn marker.
• Assign the physics body to the new segment immediately so it interacts correctly with the player's car.

Since your track segments have colliders for road edges:

• Attach a trigger collider to the car's sides (or use the car's main collider with layer filtering).
• Set up a collision detection event: when the car collides with any track edge collider, trigger the game over state.
• Assign track edges to a unique layer (e.g., "TrackEdge") so you can ignore collisions with the road surface itself.

Here's a simplified snippet to illustrate the core spawning logic (adjust for your game engine—Unity, Godot, etc.):

// TrackManager.cs
public List<TrackSegment> segmentPrefabs;
public float scrollSpeed = 5f;
private List<TrackSegment> activeSegments = new List<TrackSegment>();

void Start() {
    // Spawn initial straight segments to fill the screen
    for (int i = 0; i < 3; i++) {
        SpawnSegment(GetRandomSegment());
    }
}

void Update() {
    // Move all active segments left
    foreach (var segment in activeSegments) {
        segment.transform.Translate(Vector2.left * scrollSpeed * Time.deltaTime);
    }

    // Check if we need to spawn a new segment
    var rightmostSegment = activeSegments[activeSegments.Count - 1];
    if (rightmostSegment.spawnMarker.position.x <= Screen.width) {
        SpawnSegment(GetRandomSegment());
    }

    // Despawn segments that are off-screen left
    var leftmostSegment = activeSegments[0];
    if (leftmostSegment.transform.position.x <= -Screen.width) {
        Destroy(leftmostSegment.gameObject);
        activeSegments.RemoveAt(0);
    }
}

TrackSegment GetRandomSegment() {
    // Add weighted logic here if you want to favor certain segment types
    int randomIndex = Random.Range(0, segmentPrefabs.Count);
    return segmentPrefabs[randomIndex];
}

void SpawnSegment(TrackSegment prefab) {
    Vector2 spawnPos;
    if (activeSegments.Count == 0) {
        spawnPos = Vector2.zero;
    } else {
        var lastSegment = activeSegments[activeSegments.Count - 1];
        spawnPos = lastSegment.spawnMarker.position;
    }
    var newSegment = Instantiate(prefab, spawnPos, Quaternion.identity);
    activeSegments.Add(newSegment);
}

Pro Tip: Use object pooling instead of instantiating/destroying segments every time—it'll prevent performance drops during long play sessions.

内容的提问来源于stack exchange，提问作者Jack23