unity3D 引导（镂空）

已经好久没写博客今天我写新手必须写的新手引导（注：本文出自unity3D游戏开发这本数的案例）

shader

Shader "Unlit/Default_Mask"
{Properties{[PerRendererData] _MainTex("Sprite Texture",2D)="while"{}_Color("Tint",Color)=(1,1,1,1)_StencilComp("Stencil Comparison",Float)=8_Stencil("Stencil ID",Float)=0_StencilOp("Stencil Operation",Float)=0_StencilWriteMask("Stencil Write Mask",Float)=255_StencilReadMask("Stencil Read Mask",Float)=255_ColorMask("Color Make",Float)=15[Toggle(UNITY_UI_ALPHACLIP)]_UseUIAIphaClip("Use AIpha Clip",Float)=0_Center("Center",vector)=(0,0,0,0)_Silder("Silder",Range(0,1000))=1000}SubShader{Tags {"Queue"="Transparent""IgnoreProjector"="True""RenderType"="Transparent""PreviewType"="Plane""CanUseSpriteAtlas"="True"}Stencil{Ref[_Stencil]Comp[_StencilComp]Pass[_StencilOp]ReadMask[_StencilReadMask]WriteMask[_StencilWriteMask]}Cull OffLighting OffZWrite OffZTest [unity_GUIZTestMode]Blend SrcAlpha OneMinusSrcAlphaColorMask[_ColorMask]Pass{Name "DefauIt"CGPROGRAM#pragma vertex vert#pragma fragment frag#pragma target 2.0#include "UnityCG.cginc"#include "UnityUI.cginc"// make fog work#pragma multi_compile__UNITY_UI_ALPHACLIPstruct appdata_t{float4 vertex : POSITION;float4 color:COLOR;float2 texcoord:TEXCOORD0;UNITY_VERTEX_INPUT_INSTANCE_ID};struct v2f{float4 vertex : SV_POSITION;fixed4 color:COLOR;float2 texcoord:TEXCOORD0;float4 worldPosition:TEXCOORD1;UNITY_VERTEX_OUTPUT_STEREO};fixed4 _Color;fixed4 _TextureSampleAdd;float4 _ClipRect;float _Silder;float2 _Center;v2f vert (appdata_t IN){v2f OUT;UNITY_SETUP_INSTANCE_ID(IN);UNITY_INITIALIZE_VERTEX_OUTPUT_STEREO(OUT);OUT.worldPosition=IN.vertex;OUT.vertex=UnityObjectToClipPos(OUT.worldPosition);OUT.texcoord=IN.texcoord;OUT.color=IN.color*_Color;return OUT;}sampler2D _MainTex;fixed4 frag (v2f IN) : SV_Target{half4 color=(tex2D(_MainTex,IN.texcoord)+_TextureSampleAdd)*IN.color;color.a*=UnityGet2DClipping(IN.worldPosition.xy,_ClipRect);#ifndef UNITY_UI_ALPHACLIPclip(color.a-0.001);#endifcolor.a*=(distance(IN.worldPosition.xy,_Center.xy)> _Silder);color.rgb*=color.a;return color;}ENDCG}}
}

代码

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.UI;public class HollowOut : MonoBehaviour
{//需要聚合的对象public Image target;//Canvas对象public Canvas canvas;private Vector4 m_Center;private Material m_Material;private float m_Diameter;private float m_Currnet = 0f;Vector3[] corners = new Vector3[4];private void Awake(){target.rectTransform.GetWorldCorners(corners);m_Diameter = Vector2.Distance(WordToCanvasPos(canvas, corners[0]), WordToCanvasPos(canvas, corners[2])) / 2f;float x = corners[0].x + ((corners[3].x - corners[0].x) / 2f);float y = corners[0].y + ((corners[1].y - corners[0].y) / 2f);Vector3 center = new Vector3(x, y, 0f);Vector2 position = Vector2.zero;RectTransformUtility.ScreenPointToLocalPointInRectangle(canvas.transform as RectTransform, center, canvas.GetComponent<Camera>(),out position);center = new Vector4(position.x,position.y,0f,0f);m_Material = GetComponent<Image>().material;m_Material.SetVector("_Center", center);(canvas.transform as RectTransform).GetWorldCorners(corners);for (int i = 0; i < corners.Length; i++){m_Currnet = Mathf.Max(Vector3.Distance(WordToCanvasPos(canvas, corners[i]), center),m_Currnet);}m_Material.SetFloat("_Silder", m_Currnet);}Vector2 WordToCanvasPos(Canvas canvas,Vector3 world){Vector2 position = Vector2.zero;RectTransformUtility.ScreenPointToLocalPointInRectangle(canvas.transform as RectTransform, world, canvas.GetComponent<Camera>(),out position);return position;}float yVelocity = 0f;// Update is called once per framevoid Update(){float value = Mathf.SmoothDamp(m_Currnet, m_Diameter, ref yVelocity, 0.3f);if(!Mathf.Approximately(value,m_Currnet)){m_Currnet = value;m_Material.SetFloat("_Silder", m_Currnet);}}private void OnGUI(){if(GUILayout.Button("Test")){Awake();}}
}