Unity3D Gizmos 调试可视化

利用 Gizmos 直观地看到一些调试信息。

Unity3D Gizmos 调试可视化

在 Unity 开发中，很多时候我们需要在 Scene / Game 视图 里直观地看到一些调试信息，比如角色的攻击范围、AI 的巡逻路径、摄像机的视野等。

这时候，Unity 提供的 Gizmos 系统就是非常好用的工具。

基本用法

只要在脚本里实现 OnDrawGizmos 或 OnDrawGizmosSelected 方法，就能绘制调试辅助图形。

using UnityEngine;public class GizmosDemo : MonoBehaviour
{[SerializeField] private float radius = 2f;private void OnDrawGizmos(){// 设置颜色Gizmos.color = Color.green;// 画一个球体Gizmos.DrawWireSphere(transform.position, radius);// 画一个立方体Gizmos.color = Color.yellow;Gizmos.DrawWireCube(transform.position + Vector3.up * 2, Vector3.one);// 画一条射线Gizmos.color = Color.red;Gizmos.DrawRay(transform.position, transform.forward * 5f);}private void OnDrawGizmosSelected(){Gizmos.color = Color.cyan;Gizmos.DrawWireSphere(transform.position, radius * 1.5f);}
}

• OnDrawGizmos -> 始终显示（场景中会很乱）
• OnDrawGizmosSelected -> 只有选中物体时显示（推荐）

注：如果在视图中没有显示绘制的图形，请检查右上角的图形开关，勾选对应的脚本。

常用 Gizmos API

实际应用场景

显示攻击范围

private void OnDrawGizmosSelected()
{Gizmos.color = Color.red;Gizmos.DrawWireSphere(transform.position, attackRange);
}

显示 AI 巡逻路径

private void OnDrawGizmos()
{Gizmos.color = Color.blue;for (int i = 0; i < waypoints.Length - 1; i++){Gizmos.DrawLine(waypoints[i].position, waypoints[i + 1].position);}
}

显示摄像机视野

private void OnDrawGizmos()
{Camera cam = GetComponent<Camera>();Gizmos.color = Color.green;Gizmos.matrix = cam.transform.localToWorldMatrix;Gizmos.DrawFrustum(Vector3.zero, cam.fieldOfView, cam.farClipPlane, cam.nearClipPlane, cam.aspect);
}

通用 Gizmos 工具类

为了避免每次都写重复代码，可以整理一个 GizmosHelper 工具类，例如：

• 绘制调试网格
• 绘制扇形范围
• 绘制路径箭头

using UnityEngine;public static class GizmosHelper
{/// <summary>/// 绘制调试网格/// </summary>public static void DrawGrid(Vector3 origin, int width, int height, float cellSize, Color color){Gizmos.color = color;for (int x = 0; x <= width; x++){Gizmos.DrawLine(origin + new Vector3(x * cellSize, 0, 0),origin + new Vector3(x * cellSize, 0, height * cellSize));}for (int z = 0; z <= height; z++){Gizmos.DrawLine(origin + new Vector3(0, 0, z * cellSize),origin + new Vector3(width * cellSize, 0, z * cellSize));}}/// <summary>/// 绘制扇形范围/// </summary>public static void DrawSector(Vector3 center, Vector3 forward, float angle, float radius, int segments = 20){Gizmos.color = Color.yellow;float halfAngle = angle * 0.5f;Quaternion leftRot = Quaternion.AngleAxis(-halfAngle, Vector3.up);Quaternion rightRot = Quaternion.AngleAxis(halfAngle, Vector3.up);Vector3 leftDir = leftRot * forward * radius;Vector3 rightDir = rightRot * forward * radius;Gizmos.DrawLine(center, center + leftDir);Gizmos.DrawLine(center, center + rightDir);Vector3 lastPoint = center + leftDir;for (int i = 1; i <= segments; i++){float t = (float)i / segments;Quaternion rot = Quaternion.AngleAxis(Mathf.Lerp(-halfAngle, halfAngle, t), Vector3.up);Vector3 nextPoint = center + rot * forward * radius;Gizmos.DrawLine(lastPoint, nextPoint);lastPoint = nextPoint;}}/// <summary>/// 绘制路径箭头/// </summary>public static void DrawPath(Vector3[] points, Color color){if (points == null || points.Length < 2) return;Gizmos.color = color;for (int i = 0; i < points.Length - 1; i++){Gizmos.DrawLine(points[i], points[i + 1]);DrawArrowHead(points[i], points[i + 1], color);}}private static void DrawArrowHead(Vector3 start, Vector3 end, Color color){Vector3 dir = (end - start).normalized;Vector3 right = Quaternion.LookRotation(dir) * Quaternion.Euler(0, 150, 0) * Vector3.forward;Vector3 left = Quaternion.LookRotation(dir) * Quaternion.Euler(0, -150, 0) * Vector3.forward;Gizmos.DrawLine(end, end + right * 0.5f);Gizmos.DrawLine(end, end + left * 0.5f);}
}

使用示例：

private void OnDrawGizmos()
{// 调试网格GizmosHelper.DrawGrid(Vector3.zero, 5, 5, 1f, Color.gray);// 扇形范围GizmosHelper.DrawSector(transform.position, transform.forward, 90f, 5f);// 路径箭头Vector3[] path = { transform.position, transform.position + Vector3.forward * 3, transform.position + Vector3.right * 3 };GizmosHelper.DrawPath(path, Color.cyan);
}

效果：

注意事项

• Gizmos 只在 Scene / Game 视图 可见，不会出现在游戏发布版本。
• 在 Gizmos 面板 勾选对应脚本才能看到。
• 建议用 OnDrawGizmosSelected，避免场景太乱。

总结

• OnDrawGizmos / OnDrawGizmosSelected 是调试可视化的核心入口。
• Gizmos 常用来显示 网格、范围、路径、摄像机视野等调试辅助信息。
• 封装 GizmosHelper 工具类 能极大提高开发效率。