抛物线采样

Vector3 SampleParabola(Vector3 start, Vector3 end, float height, float t)
    {
        if (Mathf.Abs(start.y - end.y) < 0.1f)
        {
            Vector3 travelDirection = end - start;
            Vector3 result = start + t * travelDirection;
            result.y += Mathf.Sin(t * Mathf.PI) * height;
            return result;
        }
        else
        {
            Vector3 travelDirection = end - start;
            Vector3 levelDirecteion = end - new Vector3(start.x, end.y, start.z);
            Vector3 right = Vector3.Cross(travelDirection, levelDirecteion);
            Vector3 up = Vector3.Cross(right, levelDirecteion);
            if (end.y > start.y) up = -up;
            Vector3 result = start + t * travelDirection;
            result += (Mathf.Sin(t * Mathf.PI) * height) * up.normalized;
            return result;
        }
    }