Unity 编辑器篇|（十）Handles （全面总结

1. 前言
2 参数总览
3 Handles两种使用方式
- 3.1 基于Editor类的OnSceneGUI
- 3.2 基于EditorWindow
4 Handles绘制
- 4.1 Draw：绘制元几何体(点、线、面)
- - 4.1.1 抗锯齿： DrawAAPolyLine 、 DrawAAConvexPolygon
  - 4.1.2 绘制实线: DrawLine 、 DrawLines 、DrawPolyLine
  - 4.1.3 绘制虚线: DrawDottedLine 、 DrawDottedLines
  - 4.1.4 绘制贝塞尔曲线: DrawBezier
  - 4.1.5 绘制圆形圆盘: DrawSolidDisc 、 DrawSolidArc 、 DrawSolidRectangleWithOutline
  - 4.1.6 绘制圆弧: DrawWireDisc 、 DrawWireArc 、 DrawWireCube
  - 4.1.7 绘制 3D 纹理: DrawTexture3DVolume 、 DrawTexture3DSlice 、 DrawTexture3DSDF
- 4.2 Handle：可视化操作数值(Vector3、Vector2、float等)
- - 4.2.1 FreeMoveHandle
  - 4.2.2 FreeRotateHandle
  - 4.2.3 PositionHandle
  - 4.2.4 RadiusHandle
  - 4.2.5 RotationHandle
  - 4.2.6 ScaleHandle
  - 4.2.7 ScaleValueHandle
- 4.3 Caps：绘制多边形几何体(如方块，点精灵，球形，圆锥等)
- - 4.3.1 ArrowHandleCap
  - 4.3.2 CircleHandleCap
  - 4.3.3 ConeHandleCap
  - 4.3.4 CubeHandleCap
  - 4.3.5 CylinderHandleCap
  - 4.3.6 DotHandleCap
  - 4.3.7 RectangleHandleCap
- 4.4 GUI
- - 4.4.1 Label
  - 4.4.2 Button
  - 4.4.3 ScaleSlider
  - 4.4.4 Slider
  - 4.4.5 Slider2D
- 4.5 Camera：摄像机

1. 前言

在Sceneview（场景视图中）自定义3D GUI 控制器与绘制的类
Handles是Unity在场景视图中，用于操控物体的3D控制器，已内置许多操作GUI，比如我们熟悉的基于Transform对位置、缩放、旋转坐标的操作工具。当然，我们使用自定义的Editor，定义自己的Handle GUI操作显示也是可能的。这种GUIs将会非常有用于程序化生成的场景内容、“不可见”的子对象与组。比如路径点与坐标标记点。

2 参数总览

静态函数	描述
ArrowHandleCap	绘制一个类似于移动工具所用箭头的箭头。
BeginGUI	在 3D 手柄 GUI 内开始一个 2D GUI 块。
Button	创建一个 3D 按钮。
CircleHandleCap	绘制一个圆形手柄。将此手柄传递给 handle 函数。
ClearCamera	清除摄像机。
ConeHandleCap	绘制一个锥体手柄。将此手柄传递给 handle 函数。
CubeHandleCap	绘制一个立方体手柄。将此手柄传递给 handle 函数。
CylinderHandleCap	绘制一个圆柱体手柄。将此手柄传递给 handle 函数。
Disc	创建一个可使用鼠标拖动的 3D 圆盘。
DotHandleCap	绘制一个圆点手柄。将此手柄传递给 handle 函数。
DrawAAConvexPolygon	绘制使用点数组指定的抗锯齿凸多边形。
DrawAAPolyLine	绘制使用点数组和宽度指定的抗锯齿线。
DrawBezier	绘制通过给定切线的起点和终点的纹理化贝塞尔曲线。
DrawCamera	在矩形内绘制一个摄像机。
DrawDottedLine	绘制一条从 p1 到 p2 的虚线。
DrawDottedLines	从 p1 到 p2 绘制一条线。
DrawGizmos	在给定相机的后处理之前或之后绘制 GizmoSubset。
DrawLine	绘制一系列虚线段。
DrawLines	绘制一系列线段。
DrawOutline	在场景视图中围绕指定游戏对象绘制轮廓。
DrawPolyLine	绘制一条穿过 points 列表的线。
DrawSelectionFrame	在指定位置和旋转处创建一个具有指定大小的正方形。
DrawSolidArc	在 3D 空间中绘制一个圆扇形（饼图）。
DrawSolidDisc	在 3D 空间中绘制一个实心平面圆盘。
DrawSolidRectangleWithOutline	在 3D 空间中绘制一个实心轮廓矩形。
DrawTexture3DSDF	在 3D 空间中使用有符号距离场渲染模式绘制 3D 纹理。
DrawTexture3DSlice	在 3D 空间中使用切片渲染模式绘制 3D 纹理。
DrawTexture3DVolume	在 3D 空间中使用体积渲染模式绘制 3D 纹理。
DrawWireArc	在 3D 空间中绘制圆弧。
DrawWireCube	使用 center 和 size 绘制一个线框盒体。
DrawWireDisc	在 3D 空间中绘制扁平圆盘的轮廓。
EndGUI	结束一个 2D GUI 块并返回到 3D 手柄 GUI。
FreeMoveHandle	创建一个不受约束的移动手柄。
FreeRotateHandle	创建一个不受约束的旋转手柄。
GetMainGameViewSize	获取主游戏视图的宽度和高度。
Label	为位于 3D 空间中的手柄创建文本标签。
MakeBezierPoints	返回表示贝塞尔曲线的点数组。
PositionHandle	创建一个位置手柄。
RadiusHandle	创建一个场景视图半径手柄。
RectangleHandleCap	绘制一个矩形手柄。将此手柄传递给 handle 函数。
RotationHandle	创建一个场景视图旋转手柄。
ScaleHandle	创建一个场景视图缩放手柄。
ScaleSlider	创建一个定向缩放滑动条。
ScaleValueHandle	创建一个缩放单个浮点的 3D 手柄。
SetCamera	设置当前摄像机，以便所有手柄和辅助图标均使用相应设置进行绘制。
ShouldRenderGizmos	确定是否绘制 Gizmos。
Slider	创建一个沿着一个轴移动的 3D 滑动条。
Slider2D	创建一个沿两个轴定义的平面移动的 3D 滑动条。
SnapToGrid	将每个 Transform.position 或 Vector3 舍入为 EditorSnapSettings.gridSize 的最接近倍数。
SnapValue	如果对齐为 active，则将 value 四舍五入到 snap 的最接近倍数。注意，snap 只能为正数。
SphereHandleCap	绘制一个球体手柄。将此手柄传递给 handle 函数。
TransformHandle	创建变换手柄。

3 Handles两种使用方式

3.1 基于Editor类的OnSceneGUI

在继承自Editor的类中，可以定义【OnSceneGUI()】
这样当此Edtior在活跃状态时（比如一个Inspector面板展开），在【OnSceneGUI()】方法内的内容将根据SceneView的刷新而调用，触发对应逻辑。

using UnityEngine;

public class HandlesScript : MonoBehaviour
{

}

using UnityEditor;
using UnityEngine;

[CustomEditor(typeof(HandlesScript))]
public class HandlesEditor : Editor
{
    private void OnSceneGUI()
    {
        Debug.Log("在Editor OnSceneGUI中 调用....");
    }
}

在【Hierarchy】中新建空对象，挂载脚本，点击对象在【Inspector】中显示【HandlesScript】信息，就可以看见信息打印：

注：下文实例代码都是在OnSceneGUI中编写调用。

3.2 基于EditorWindow

有些时候，我们更想在一个Window中进行数据编辑与操作，但是EditorWindow可没有OnSceneGUI，怎么办呢？这时候，需要手动对SceneView的刷新事件进行注册了。

using UnityEngine;
using UnityEditor;
public class HandlesWindow : EditorWindow
{
    public static HandlesWindow m_mainWindow;

    [MenuItem("MyWindows/HandlesWindow")]
    public static void OpenWindow() //打开窗口
    {
        m_mainWindow = EditorWindow.GetWindow<HandlesWindow>();
        m_mainWindow.Show();
    }
    private void OnEnable() 
    {
        SceneView.duringSceneGui += OnSceneGUI; //对SceneView的刷新事件进行注册
    }
    private void OnDisable() 
    {
        SceneView.duringSceneGui -= OnSceneGUI; //对SceneView的刷新事件取消注册
    }
    private void OnSceneGUI(SceneView sceneView) //自定义刷新事件的委托方法
    {
        Debug.Log("在 Window OnSceneGUI中 调用...."); //具体逻辑
    }
}

4 Handles绘制

4.1 Draw：绘制元几何体(点、线、面)

4.1.1 抗锯齿： DrawAAPolyLine 、 DrawAAConvexPolygon

DrawAAPolyLine：绘制使用点数组和宽度指定的抗锯齿线。
- 注意：如果您希望拥有恒定屏幕大小的手柄，请使用 HandleUtility.GetHandleSize。
- 注意：要获得抗锯齿效果，请使用 1x2 像素（一个透明的白色像素和一个不透明的白色像素）的纹理。
DrawAAConvexPolygon：绘制使用点数组指定的抗锯齿凸多边形。

DrawAAPolyLine

using UnityEditor;
using UnityEngine;

[CustomEditor(typeof(HandlesScript))]
public class HandlesEditor : Editor
{
    private void OnSceneGUI()
    {
        Handles.DrawAAPolyLine(new Vector3[] { Vector3.zero, Vector3.one, new Vector3(2, 0, 2) });
    }
}

DrawAAConvexPolygon

using UnityEditor;
using UnityEngine;

[CustomEditor(typeof(HandlesScript))]
[CanEditMultipleObjects]
public class HandlesEditor : Editor
{
    private void OnSceneGUI()
    {
        Handles.DrawAAConvexPolygon(new Vector3[] { Vector3.zero, Vector3.one, new Vector3(2, 0, 2) });
    }
}

4.1.2 绘制实线: DrawLine 、 DrawLines 、DrawPolyLine

DrawLine：从 p1 到 p2 绘制一条线。
DrawLines：绘制一系列线段。
DrawPolyLine：绘制一条穿过 points 列表的线。

DrawLine

using UnityEditor;
using UnityEngine;

[CustomEditor(typeof(HandlesScript))]
public class HandlesEditor : Editor
{
    private void OnSceneGUI()
    {
        Handles.DrawLine(Vector3.zero, Vector3.one);
    }
}

DrawLines

using UnityEditor;
using UnityEngine;

[CustomEditor(typeof(HandlesScript))]
public class HandlesEditor : Editor
{
    Vector3[] lineSegments = new Vector3[4]
    {
        //线段一
        Vector3.zero, Vector3.one,
        //线段二
        Vector3.one, new Vector3(2,0,2)
    };
    private void OnSceneGUI()
    { 
        Handles.DrawLines(lineSegments);
    }
}

DrawPolyLine

using UnityEditor;
using UnityEngine;

[CustomEditor(typeof(HandlesScript))]
public class HandlesEditor : Editor
{
    Vector3[] positions = new Vector3[4]
  {
        Vector3.zero, Vector3.one, new Vector3(2,0,2), Vector3.zero
  };
    private void OnSceneGUI()
    {
        Handles.DrawPolyLine(positions);
    }
}

4.1.3 绘制虚线: DrawDottedLine 、 DrawDottedLines

DrawDottedLine：绘制一条从 p1 到 p2 的虚线。
DrawDottedLines：绘制一系列虚线段。

DrawDottedLine

using UnityEditor;
using UnityEngine;

[CustomEditor(typeof(HandlesScript))]
public class HandlesEditor : Editor
{
    //线段长度及其间距的大小（以像素为单位）。
    float screenSpaceSize = 4.0f;
    private void OnSceneGUI()
    {
        Handles.DrawDottedLine(Vector3.zero, Vector3.one, screenSpaceSize);
    }
}

DrawDottedLines

using UnityEditor;
using UnityEngine;

[CustomEditor(typeof(HandlesScript))]
public class HandlesEditor : Editor
{
    Vector3[] lineSegments = new Vector3[4]
    {
        //线段一
        Vector3.zero, Vector3.one,
        //线段二
        Vector3.one, new Vector3(2,0,2)
    };

    //线段长度及其间距的大小（以像素为单位）。
    float screenSpaceSize = 4.0f;
    private void OnSceneGUI()
    {
        Handles.DrawDottedLines(lineSegments, screenSpaceSize);
    }
}

4.1.4 绘制贝塞尔曲线: DrawBezier

DrawBezier：绘制通过给定切线的起点和终点的纹理化贝塞尔曲线。

using UnityEditor;
using UnityEngine;

[CustomEditor(typeof(HandlesScript))]
public class HandlesEditor : Editor
{
    public Vector3 startPoint = new Vector3(-0.0f, 0.0f, 0.0f);//贝塞尔曲线的起点。
    public Vector3 endPoint = new Vector3(-2.0f, 1.0f, 0.0f);//贝塞尔曲线的终点。
    public Vector3 startTangent = new Vector3(-2.0f, 2.0f, 0.0f);//贝塞尔曲线的起始切线。
    public Vector3 endTangent = Vector3.zero;//贝塞尔曲线的终点切线。
    private void OnSceneGUI()
    {
        Handles.DrawBezier(startPoint, endPoint, startTangent, endTangent, Color.red, null, 2f);
    }
}

4.1.5 绘制圆形圆盘: DrawSolidDisc 、 DrawSolidArc 、 DrawSolidRectangleWithOutline

DrawSolidDisc：在 3D 空间中绘制一个实心平面圆盘。
DrawSolidArc：在 3D 空间中绘制一个圆扇形（饼图）。
**DrawSolidRectangleWithOutline **：在 3D 空间中绘制一个实心轮廓矩形。

DrawSolidDisc

using UnityEditor;
using UnityEngine;

[CustomEditor(typeof(HandlesScript))]
public class HandlesEditor : Editor
{
    //圆盘的中心。
    Vector3 center = Vector3.zero;
    //圆盘的法线。
    Vector3 normal = Vector3.up;
    //该圆盘的半径。
    float radius = 1.0f;
    private void OnSceneGUI()
    {
        Handles.DrawSolidDisc(center, normal, radius);
    }
}

DrawSolidArc

using UnityEditor;
using UnityEngine;

[CustomEditor(typeof(HandlesScript))]
public class HandlesEditor : Editor
{
    //圆盘的中心。
    Vector3 center = Vector3.zero;
    //圆盘的法线。
    Vector3 normal = Vector3.up;
    //圆周上的点相对于圆心的方向，即扇形的起点。
    Vector3 from = Vector3.left;
    //扇形的角度（以度为单位）。
    float angle = 180;
    //该圆盘的半径。
    float radius = 1.0f;
    private void OnSceneGUI()
    {
        Handles.DrawSolidArc(center, normal, from, angle, radius);
    }
}

DrawSolidRectangleWithOutline

using UnityEditor;
using UnityEngine;

[CustomEditor(typeof(HandlesScript))]
public class HandlesEditor : Editor
{
    private void OnSceneGUI()
    {
        HandlesScript t = target as HandlesScript;
        Vector3 pos = t.transform.position;

        Vector3[] verts = new Vector3[]
        {
            new Vector3(pos.x -2, pos.y, pos.z -2),
            new Vector3(pos.x -2, pos.y, pos.z + 2),
            new Vector3(pos.x + 2, pos.y, pos.z + 2),
            new Vector3(pos.x +2, pos.y, pos.z -2)
        };

        Handles.DrawSolidRectangleWithOutline(verts, new Color(0.5f, 0.5f, 0.5f, 0.1f), new Color(0, 0, 0, 1));
    }
}

4.1.6 绘制圆弧: DrawWireDisc 、 DrawWireArc 、 DrawWireCube

DrawWireDisc：在 3D 空间中绘制扁平圆盘的轮廓。
DrawWireArc：在 3D 空间中绘制圆弧。
DrawWireCube：使用 center 和 size 绘制一个线框盒体。

DrawWireDisc

using UnityEditor;
using UnityEngine;

[CustomEditor(typeof(HandlesScript))]
public class HandlesEditor : Editor
{
    //圆盘的中心。
    Vector3 center = Vector3.zero;
    //圆盘的法线。
    Vector3 normal = Vector3.up;
    //条粗细（零粗细绘制单像素线条）。
    float thickness = 3;
    //该圆盘的半径。
    float radius = 1.0f;
    private void OnSceneGUI()
    {
        Handles.color = Color.red;
        Handles.DrawWireDisc(center, normal, radius, thickness);
    }
}

DrawWireArc

using UnityEditor;
using UnityEngine;

[CustomEditor(typeof(HandlesScript))]
public class HandlesEditor : Editor
{
    //圆盘的中心。
    Vector3 center = Vector3.zero;
    //圆盘的法线。
    Vector3 normal = Vector3.up;
    //圆周上的点相对于圆心的方向，即圆弧的起点。
    Vector3 from = Vector3.left;
    //条粗细（零粗细绘制单像素线条）。
    float thickness = 3;
    //圆的半径。
    float angle = 180;
    //该圆盘的半径。
    float radius = 1.0f;
    private void OnSceneGUI()
    {
        Handles.color = Color.red;
        Handles.DrawWireArc(center, normal, from, angle, radius, thickness);
    }
}

DrawWireCube

using UnityEditor;
using UnityEngine;

[CustomEditor(typeof(HandlesScript))]
public class HandlesEditor : Editor
{
    Vector3 center = Vector3.zero;
    Vector3 size = Vector3.one;
    private void OnSceneGUI()
    {
        Handles.color = Color.red;
        Handles.DrawWireCube(center, size);
    }
}

4.1.7 绘制 3D 纹理: DrawTexture3DVolume 、 DrawTexture3DSlice 、 DrawTexture3DSDF

DrawTexture3DVolume：在 3D 空间中使用体积渲染模式绘制 3D 纹理。
DrawTexture3DSlice：在 3D 空间中使用切片渲染模式绘制 3D 纹理。
DrawTexture3DSDF：在 3D 空间中使用有符号距离场渲染模式绘制 3D 纹理。

DrawTexture3DVolume

using UnityEditor;
using UnityEngine;

[CustomEditor(typeof(HandlesScript))]
[CanEditMultipleObjects]
public class HandlesEditor : Editor
{
    //要绘制的体积纹理。
    public Texture texture;
    //非线性体积不透明度修改器。使用它来控制可视化的不透明度。有效值为 0-1（含）。
    //值为 1 时完全不透明，值为 0 时完全透明。默认值为 1。
    float opacity = 0;
    //设置每个纹理像素计数的样本。值越高，渲染质量越高。默认值为 1。
    float qualityModifier = 0;
    //设置要使用的纹理过滤模式。
    FilterMode filterMode = FilterMode.Trilinear;
    //启用颜色渐变可视化。
    bool useColorRamp = true;
    //Unity 用作颜色渐变的自定义渐变。如果未指定，Unity 将使用 Google Turbo 色带。
    Gradient customColorRamp;
    private void OnSceneViewGUI(SceneView sv)
    {
        Handles.DrawTexture3DVolume(texture, opacity, qualityModifier, filterMode,
            useColorRamp, useColorRamp ? customColorRamp : null);
    }
}

DrawTexture3DSlice

using UnityEditor;
using UnityEngine;

[CustomEditor(typeof(HandlesScript))]
[CanEditMultipleObjects]
public class HandlesEditor : Editor
{
    //要绘制的体积纹理。
    public Texture texture;
    //纹理采样平面的位置。
    public Vector3 slicePositions;
    //设置要使用的纹理过滤模式。
    FilterMode filterMode = FilterMode.Trilinear;
    //启用颜色渐变可视化。
    bool useColorRamp = true;
    //Unity 用作颜色渐变的自定义渐变。如果未指定，Unity 将使用 Google Turbo 色带。
    Gradient customColorRamp;
    private void OnSceneViewGUI(SceneView sv)
    {
        Handles.DrawTexture3DSlice(texture, slicePositions, filterMode,
            useColorRamp, useColorRamp ? customColorRamp : null);
    }
}

DrawTexture3DSDF

using UnityEditor;
using UnityEngine;

[CustomEditor(typeof(HandlesScript))]
[CanEditMultipleObjects]
public class HandlesEditor : Editor
{
    //要绘制的体积纹理。
    public Texture texture;
    //与光线步长相乘的数字。光线步长是两个相邻像素之间的距离。默认值为 1。
    float stepScale;
    //渲染表面时的像素强度。当该值为正数时，Unity 将扩展渲染表面。
    //当该值为负数时，Unity 会将空的空间渲染为表面，并将表面渲染为空的空间。默认值为 0。
    float surfaceOffset;
    //Unity 用作颜色渐变的自定义渐变。如果未指定，Unity 将使用 Google Turbo 色带。
    Gradient customColorRamp;
    private void OnSceneViewGUI(SceneView sv)
    {
        Handles.DrawTexture3DSDF(texture, stepScale, surfaceOffset, customColorRamp);
    }
}

4.2 Handle：可视化操作数值(Vector3、Vector2、float等)

4.2.1 FreeMoveHandle

FreeMoveHandle：创建一个不受约束的移动手柄。

 protected virtual void OnSceneGUI()
 {
     HandlesScript example = (HandlesScript)target;

     float size = HandleUtility.GetHandleSize(example.targetPosition) * 0.5f;
     Vector3 snap = Vector3.one * 0.5f;

     EditorGUI.BeginChangeCheck();
     Vector3 newTargetPosition = Handles.FreeMoveHandle(example.targetPosition, Quaternion.identity, size, snap, Handles.RectangleHandleCap);
     if (EditorGUI.EndChangeCheck())
     {
         Undo.RecordObject(example, "Change Look At Target Position");
         example.targetPosition = newTargetPosition;
         example.Update();
     }
 }

using UnityEngine;

public class HandlesScript : MonoBehaviour
{
    public Vector3 targetPosition { get { return m_TargetPosition; } set { m_TargetPosition = value; } }
    [SerializeField]
    private Vector3 m_TargetPosition = new Vector3(1f, 0f, 2f);

    public virtual void Update()
    {
        transform.LookAt(m_TargetPosition);
    }
}

4.2.2 FreeRotateHandle

FreeRotateHandle：创建一个不受约束的旋转手柄。

 public void OnSceneGUI()
 {
     HandlesScript t = (target as HandlesScript);

     EditorGUI.BeginChangeCheck();
     Quaternion rot = Handles.FreeRotateHandle(0, t.rot, Vector3.zero, 2);
     if (EditorGUI.EndChangeCheck())
     {
         Undo.RecordObject(target, "Free Rotate");
         t.rot = rot;
         t.Update();
     }
 }

using UnityEngine;

public class HandlesScript : MonoBehaviour
{
    public Quaternion rot = Quaternion.identity;
    public void Update()
    {
        transform.rotation = rot;
    }
}

4.2.3 PositionHandle

PositionHandle：创建一个位置手柄。

 protected virtual void OnSceneGUI()
    {
        HandlesScript example = (HandlesScript)target;

        EditorGUI.BeginChangeCheck();
        Vector3 newTargetPosition = Handles.PositionHandle(example.targetPosition, Quaternion.identity);
        if (EditorGUI.EndChangeCheck())
        {
            Undo.RecordObject(example, "Change Look At Target Position");
            example.targetPosition = newTargetPosition;
            example.Update();
        }
    }

using UnityEngine;

public class HandlesScript : MonoBehaviour
{
    public Vector3 targetPosition { get { return m_TargetPosition; } set { m_TargetPosition = value; } }
    [SerializeField]
    private Vector3 m_TargetPosition = new Vector3(1f, 0f, 2f);

    public virtual void Update()
    {
        transform.LookAt(m_TargetPosition);
    }
}

4.2.4 RadiusHandle

RadiusHandle：创建一个场景视图半径手柄。

using UnityEngine;

public class HandlesScript : MonoBehaviour
{
    public float areaOfEffect = 1;
}

public void OnSceneGUI()
{
    HandlesScript t = (target as HandlesScript);

    EditorGUI.BeginChangeCheck();
    float areaOfEffect = Handles.RadiusHandle(Quaternion.identity, t.transform.position, t.areaOfEffect);
    if (EditorGUI.EndChangeCheck())
    {
        Undo.RecordObject(target, "Changed Area Of Effect");
        t.areaOfEffect = areaOfEffect;
    }
}

4.2.5 RotationHandle

RotationHandle：创建一个场景视图旋转手柄。

using UnityEngine;

public class HandlesScript : MonoBehaviour
{
    public Quaternion rot = Quaternion.identity;
    public void Update()
    {
        transform.rotation = rot;
    }
}

 public void OnSceneGUI()
    {
        HandlesScript t = (target as HandlesScript );

        EditorGUI.BeginChangeCheck();
        Quaternion rot = Handles.RotationHandle(t.rot, Vector3.zero);
        if (EditorGUI.EndChangeCheck())
        {
            Undo.RecordObject(target, "Rotated RotateAt Point");
            t.rot = rot;
            t.Update();
        }
    }

4.2.6 ScaleHandle

ScaleHandle：创建一个场景视图缩放手柄。

using UnityEngine;

public class HandlesScript : MonoBehaviour
{
    public Vector3 scale = Vector3.one;
    public void Update()
    {
        transform.localScale = scale;
    }
}

 public void OnSceneGUI()
    {
        HandlesScript t = (target as HandlesScript );

        EditorGUI.BeginChangeCheck();
        Vector3 scale = Handles.ScaleHandle(t.scale, Vector3.zero, Quaternion.identity, 1);
        if (EditorGUI.EndChangeCheck())
        {
            Undo.RecordObject(target, "Scaled ScaleAt Point");
            t.scale = scale;
            t.Update();
        }
    }

4.2.7 ScaleValueHandle

ScaleValueHandle：创建一个缩放单个浮点的 3D 手柄。

using UnityEngine;

public class HandlesScript : MonoBehaviour
{
    [SerializeField]
    private Color m_Color1 = Color.red;
    [SerializeField]
    private Color m_Color2 = Color.green;

    public float amount { get { return m_Amount; } set { m_Amount = Mathf.Clamp01(value); } }
    [SerializeField, Range(0f, 1f)]
    private float m_Amount = 1f;

    private Light m_Light;

    protected virtual void OnEnable()
    {
        m_Light = GetComponent<Light>();
    }

    public virtual void Update()
    {
        m_Light.color = Color.Lerp(m_Color1, m_Color2, m_Amount);
    }
}

 protected virtual void OnSceneGUI()
    {
        LightColorLerp colorLerp = (LightColorLerp)target;

        float size = HandleUtility.GetHandleSize(colorLerp.transform.position) * 5f;
        float snap = 0.1f;

        EditorGUI.BeginChangeCheck();
        float newAmount = Handles.ScaleValueHandle(colorLerp.amount, colorLerp.transform.position, Quaternion.identity, size, Handles.ArrowHandleCap, snap);
        if (EditorGUI.EndChangeCheck())
        {
            Undo.RecordObject(colorLerp, "Change Light Color Interpolation");
            colorLerp.amount = newAmount;
            colorLerp.Update();
        }
    }

4.3 Caps：绘制多边形几何体(如方块，点精灵，球形，圆锥等)

4.3.1 ArrowHandleCap

ArrowHandleCap：绘制一个类似于移动工具所用箭头的箭头。

using System.Drawing.Drawing2D;
using UnityEditor;
using UnityEngine;

[CustomEditor(typeof(HandlesScript))]
[CanEditMultipleObjects]
public class HandlesEditor : Editor
{
    float size = 1f;

    protected virtual void OnSceneGUI()
    {
        if (Event.current.type == EventType.Repaint)
        {
            Transform transform = ((HandlesScript)target).transform;
            Handles.color = Handles.yAxisColor;
            Handles.ArrowHandleCap(
                0,
                transform.position + new Vector3(3f, 0f, 0f),
                transform.rotation * Quaternion.LookRotation(Vector3.right),
                size,
                EventType.Repaint
            );
            Handles.color = Handles.yAxisColor;
            Handles.ArrowHandleCap(
                0,
                transform.position + new Vector3(0f, 3f, 0f),
                transform.rotation * Quaternion.LookRotation(Vector3.up),
                size,
                EventType.Repaint
            );
            Handles.color = Handles.yAxisColor;
            Handles.ArrowHandleCap(
                0,
                transform.position + new Vector3(0f, 0f, 3f),
                transform.rotation * Quaternion.LookRotation(Vector3.forward),
                size,
                EventType.Repaint
            );
        }
    }
}

4.3.2 CircleHandleCap

CircleHandleCap：绘制一个圆形手柄。将此手柄传递给 handle 函数。

using System.Drawing.Drawing2D;
using UnityEditor;
using UnityEngine;

[CustomEditor(typeof(HandlesScript))]
[CanEditMultipleObjects]
public class HandlesEditor : Editor
{
    float size = 1f;

    protected virtual void OnSceneGUI()
    {
        if (Event.current.type == EventType.Repaint)
        {
            Transform transform = ((HandlesScript)target).transform;
            Handles.color = Handles.xAxisColor;
            Handles.CircleHandleCap(
                0,
                transform.position + new Vector3(3f, 0f, 0f),
                transform.rotation * Quaternion.LookRotation(Vector3.right),
                size,
                EventType.Repaint
            );
            Handles.color = Handles.yAxisColor;
            Handles.CircleHandleCap(
                0,
                transform.position + new Vector3(0f, 3f, 0f),
                transform.rotation * Quaternion.LookRotation(Vector3.up),
                size,
                EventType.Repaint
            );
            Handles.color = Handles.zAxisColor;
            Handles.CircleHandleCap(
                0,
                transform.position + new Vector3(0f, 0f, 3f),
                transform.rotation * Quaternion.LookRotation(Vector3.forward),
                size,
                EventType.Repaint
            );
        }
    }
}

4.3.3 ConeHandleCap

ConeHandleCap：绘制一个锥体手柄。将此手柄传递给 handle 函数。

using UnityEditor;
using UnityEngine;

[CustomEditor(typeof(HandlesScript))]
[CanEditMultipleObjects]
public class HandlesEditor : Editor
{
    float size = 1f;

    protected virtual void OnSceneGUI()
    {
        if (Event.current.type == EventType.Repaint)
        {
            Transform transform = ((HandlesScript)target).transform;
            Handles.color = Handles.xAxisColor;
            Handles.ConeHandleCap(
                0,
                transform.position + new Vector3(3f, 0f, 0f),
                transform.rotation * Quaternion.LookRotation(Vector3.right),
                size,
                EventType.Repaint
            );
            Handles.color = Handles.yAxisColor;
            Handles.ConeHandleCap(
                0,
                transform.position + new Vector3(0f, 3f, 0f),
                transform.rotation * Quaternion.LookRotation(Vector3.up),
                size,
                EventType.Repaint
            );
            Handles.color = Handles.zAxisColor;
            Handles.ConeHandleCap(
                0,
                transform.position + new Vector3(0f, 0f, 3f),
                transform.rotation * Quaternion.LookRotation(Vector3.forward),
                size,
                EventType.Repaint
            );
        }
    }
}

4.3.4 CubeHandleCap

CubeHandleCap：绘制一个立方体手柄。将此手柄传递给 handle 函数。

using UnityEditor;
using UnityEngine;

[CustomEditor(typeof(HandlesScript))]
[CanEditMultipleObjects]
public class HandlesEditor : Editor
{
    float size = 1f;

    protected virtual void OnSceneGUI()
    {
        if (Event.current.type == EventType.Repaint)
        {
            Transform transform = ((HandlesScript)target).transform;
            Handles.color = Handles.xAxisColor;
            Handles.CubeHandleCap(
                0,
                transform.position + new Vector3(3f, 0f, 0f),
                transform.rotation * Quaternion.LookRotation(Vector3.right),
                size,
                EventType.Repaint
            );
            Handles.color = Handles.yAxisColor;
            Handles.CubeHandleCap(
                0,
                transform.position + new Vector3(0f, 3f, 0f),
                transform.rotation * Quaternion.LookRotation(Vector3.up),
                size,
                EventType.Repaint
            );
            Handles.color = Handles.zAxisColor;
            Handles.CubeHandleCap(
                0,
                transform.position + new Vector3(0f, 0f, 3f),
                transform.rotation * Quaternion.LookRotation(Vector3.forward),
                size,
                EventType.Repaint
            );
        }
    }
}

4.3.5 CylinderHandleCap

CylinderHandleCap：绘制一个圆柱体手柄。将此手柄传递给 handle 函数。

using UnityEditor;
using UnityEngine;

[CustomEditor(typeof(HandlesScript))]
[CanEditMultipleObjects]
public class HandlesEditor : Editor
{
    float size = 1f;

    protected virtual void OnSceneGUI()
    {
        if (Event.current.type == EventType.Repaint)
        {
            Transform transform = ((HandlesScript)target).transform;
            Handles.color = Handles.xAxisColor;
            Handles.CylinderHandleCap(
                0,
                transform.position + new Vector3(3f, 0f, 0f),
                transform.rotation * Quaternion.LookRotation(Vector3.right),
                size,
                EventType.Repaint
            );
            Handles.color = Handles.yAxisColor;
            Handles.CylinderHandleCap(
                0,
                transform.position + new Vector3(0f, 3f, 0f),
                transform.rotation * Quaternion.LookRotation(Vector3.up),
                size,
                EventType.Repaint
            );
            Handles.color = Handles.zAxisColor;
            Handles.CylinderHandleCap(
                0,
                transform.position + new Vector3(0f, 0f, 3f),
                transform.rotation * Quaternion.LookRotation(Vector3.forward),
                size,
                EventType.Repaint
            );
        }
    }
}

4.3.6 DotHandleCap

DotHandleCap：绘制一个圆点手柄。将此手柄传递给 handle 函数。

using UnityEditor;
using UnityEngine;

[CustomEditor(typeof(HandlesScript))]
public class HandlesEditor : Editor
{
    float size = 1f;

    protected virtual void OnSceneGUI()
    {
        if (Event.current.type == EventType.Repaint)
        {
            Transform transform = ((HandlesScript)target).transform;
            Handles.color = Handles.xAxisColor;
            Handles.DotHandleCap(
                0,
                transform.position + new Vector3(3f, 0f, 0f),
                transform.rotation * Quaternion.LookRotation(Vector3.right),
                size,
                EventType.Repaint
            );
            Handles.color = Handles.yAxisColor;
            Handles.DotHandleCap(
                0,
                transform.position + new Vector3(0f, 3f, 0f),
                transform.rotation * Quaternion.LookRotation(Vector3.up),
                size,
                EventType.Repaint
            );
            Handles.color = Handles.zAxisColor;
            Handles.DotHandleCap(
                0,
                transform.position + new Vector3(0f, 0f, 3f),
                transform.rotation * Quaternion.LookRotation(Vector3.forward),
                size,
                EventType.Repaint
            );
        }
    }
}

4.3.7 RectangleHandleCap

RectangleHandleCap：绘制一个矩形手柄。将此手柄传递给 handle 函数。

using UnityEditor;
using UnityEngine;

[CustomEditor(typeof(HandlesScript))]
public class HandlesEditor : Editor
{
    float size = 1f;

    protected virtual void OnSceneGUI()
    {
        if (Event.current.type == EventType.Repaint)
        {
            Transform transform = ((HandlesScript)target).transform;
            Handles.color = Handles.xAxisColor;
            Handles.RectangleHandleCap(
                0,
                transform.position + new Vector3(3f, 0f, 0f),
                transform.rotation * Quaternion.LookRotation(Vector3.right),
                size,
                EventType.Repaint
            );
            Handles.color = Handles.yAxisColor;
            Handles.RectangleHandleCap(
                0,
                transform.position + new Vector3(0f, 3f, 0f),
                transform.rotation * Quaternion.LookRotation(Vector3.up),
                size,
                EventType.Repaint
            );
            Handles.color = Handles.zAxisColor;
            Handles.RectangleHandleCap(
                0,
                transform.position + new Vector3(0f, 0f, 3f),
                transform.rotation * Quaternion.LookRotation(Vector3.forward),
                size,
                EventType.Repaint
            );
        }
    }
}

4.4 GUI

4.4.1 Label

Label：为位于 3D 空间中的手柄创建文本标签。

using UnityEditor;
using UnityEngine;

[CustomEditor(typeof(HandlesScript))]
public class HandlesEditor : Editor
{
    protected virtual void OnSceneGUI()
    {
        Handles.color = Color.red;
        Handles.Label(Vector3.zero,"测试Label");
    }
}

4.4.2 Button

Button：创建一个 3D 按钮。

using UnityEditor;
using UnityEngine;

[CustomEditor(typeof(HandlesScript))]
public class HandlesEditor : Editor
{
    protected virtual void OnSceneGUI()
    {
        if (Handles.Button(Vector3.zero, Quaternion.identity, 1, 2, Handles.RectangleHandleCap))
            Debug.Log("The button was pressed!");
    }
}

4.4.3 ScaleSlider

ScaleSlider：创建一个定向缩放滑动条。

using UnityEditor;
using UnityEngine;

[CustomEditor(typeof(HandlesScript))]
public class HandlesEditor : Editor
{
    protected virtual void OnSceneGUI()
    {
        float scale = Handles.ScaleSlider(1, Vector3.zero, Vector3.right, Quaternion.identity, 1, 0.5f);
    }
}

4.4.4 Slider

Slider：创建一个沿着一个轴移动的 3D 滑动条。

using UnityEditor;
using UnityEngine;

[CustomEditor(typeof(HandlesScript))]
public class HandlesEditor : Editor
{
    protected virtual void OnSceneGUI()
    {
        Vector3 newTargetPosition = Handles.Slider(Vector3.zero, Vector3.right, 1, Handles.ConeHandleCap, 0.5f);
    }
}

4.4.5 Slider2D

Slider2D：创建一个沿两个轴定义的平面移动的 3D 滑动条。

using UnityEditor;
using UnityEngine;

[CustomEditor(typeof(HandlesScript))]
public class HandlesEditor : Editor
{
    protected virtual void OnSceneGUI()
    {
        Vector3 newTargetPosition = Handles.Slider2D(Vector3.zero, Vector3.up, Vector3.right, Vector3.forward, 1, Handles.CircleHandleCap, 0.5f);
    }
}

4.5 Camera：摄像机

DrawCamera：在矩形内绘制一个摄像机。此函数还将 Camera.current 设置为 camera。它将摄像机的 pixelRect 设置为 position，但采用屏幕坐标。如果您使用高 DPI 显示屏，这可能会与 GUI 坐标有所不同。
ClearCamera：清除摄像机。Handle 类使用的摄像机将在使用前被清除
SnapValue：如果对齐为 active，则将 value 四舍五入到 snap 的最接近倍数。注意，snap 只能为正数。