Shader学习14——平面扫描效果

之前一直有人找我要EasyAR那种摄像头的扫描线效果shader，这个其实是我几年前写的，这里也懒得注释了，直接发出来分享给大家吧，做了一些过渡渐隐的效果。
效果如下：

shader代码：

Shader "Unlit/平面扫描"
{
    Properties 
    {
        _MainTex ("Main Tex", 2D) = "white" {}

        _SacnLinePosition("扫描线位置",Range (0,1))=1
        _SacnLineWidth("扫描线宽度",Range (0,0.1))=0.05


        _StrokeRange("描边厚度",Range (0,0.2))=0.05
        _StrokeColor ("描边颜色", Color) = (1, 1, 1, 1)
        _SacnLineAlpha("扫描线淡度",Range (0,1))=1


        jingdu("jingdu",Range (0.00000001,0.1))=0.001
    }
     
    SubShader 
    {
        Tags {"Queue"="Transparent" "IgnoreProjector"="True" "RenderType"="Transparent" "PreviewType"="Plane" "CanUseSpriteAtlas"="True"}
         
        Pass 
        {
            Tags { "LightMode"="ForwardBase" }
            ZTest off
            ZWrite Off
            Cull Off
            Lighting Off
            Fog { Mode Off }
            Blend SrcAlpha OneMinusSrcAlpha
             
    
            CGPROGRAM
            #pragma vertex vert  
            #pragma fragment frag
            #pragma multi_compile DUMMY PIXELSNAP_ON
             
             
            sampler2D _MainTex;
            fixed3 _MaskColor;

            float _StrokeRange;
            fixed3 _ComparColor;
            fixed4 _StrokeColor;
            float _SacnLinePosition;
            float _SacnLineWidth;

            float _SacnLineAlpha;

            float jingdu;
            struct a2v 
            {  
                float4 vertex : POSITION; 
                float3 texcoord : TEXCOORD0;
            };  
             
            struct v2f 
            {  
                float4 pos : SV_POSITION;
                float2 uv : TEXCOORD0;
            };  

            v2f vert (a2v v) 
            {  
                v2f o;  
                o.pos = UnityObjectToClipPos(v.vertex);  
                o.uv = v.texcoord;
                return o;
            }  
            fixed r_abs;
            fixed g_abs;
            fixed b_abs;

            fixed4 frag (v2f i) : SV_Target 
            {
                fixed4 c = tex2D(_MainTex, i.uv);

                if(i.uv.y>=_SacnLinePosition)
                {
                    if(i.uv.y<=_SacnLinePosition+_SacnLineWidth)
                    c.rgb+=_SacnLineAlpha*0.1*_StrokeColor*(_SacnLinePosition+_SacnLineWidth-i.uv.y)/_SacnLineWidth;
                
                    _ComparColor=tex2D(_MainTex, i.uv+ float2(0,jingdu)).rgb;   
                    r_abs=abs(c.r-_ComparColor.r);
                    g_abs=abs(c.g-_ComparColor.g);
                    b_abs=abs(c.b-_ComparColor.b);
                    if((r_abs>_StrokeRange&&g_abs>_StrokeRange)||(r_abs>_StrokeRange&&b_abs>_StrokeRange)||(b_abs>_StrokeRange&&b_abs>_StrokeRange))
                    {
                        c.rgb+=_SacnLineAlpha*_StrokeColor;
                    }

                    _ComparColor=tex2D(_MainTex, i.uv+ float2(jingdu,0)).rgb;   
                    r_abs=abs(c.r-_ComparColor.r);
                    g_abs=abs(c.g-_ComparColor.g);
                    b_abs=abs(c.b-_ComparColor.b);
                    if((r_abs>_StrokeRange&&g_abs>_StrokeRange)||(r_abs>_StrokeRange&&b_abs>_StrokeRange)||(b_abs>_StrokeRange&&b_abs>_StrokeRange))
                    {
                        c.rgb+=_SacnLineAlpha*_StrokeColor;
                    }

                }
                return c;
            }
            ENDCG
        }  
    }
    FallBack "Transparent/VertexLit"
}

c#控制脚本代码：

using UnityEngine;
using System.Collections;

public class LineScan : MonoBehaviour
{
    public LineState LineState = new LineState ();
        
    //扫描的速度
    [Range (0.001f, 1)]
    public float _showSpeed = 0.01f;
    [Range (0.001f, 0.2f)]
    public float _missSpeed=0.05f;
    [Range (0.1f, 5f)]
    public float IntervalTime=1f;
    private MeshRenderer _render;

    private void Awake ()
    {
        _render = GetComponent<MeshRenderer> ();
        LineState = LineState.end;
        SetX (1);
        StartCoroutine (ChangeLineStateDown());
    }

    public void SetX (float val)
    {
        _render.material.SetFloat ("_SacnLinePosition", val);
    }
    public void Set_AlphaRange (float val)
    {
        _render.material.SetFloat ("_SacnLineAlpha", val);
    }

    public float deltaX = 1;
    public float _AlphaRange=1;
    void Update(){
        switch (LineState) {
        case LineState.down:
            _AlphaRange = 1;
            Set_AlphaRange (_AlphaRange);
            if (deltaX > 0) {
                deltaX = Mathf.Clamp01 (deltaX - _showSpeed);
                SetX (deltaX);
            } else {
                deltaX = 1;
                LineState = LineState.miss;
            }
            break;
        case LineState.miss:
            if (_AlphaRange > 0.01f) {
                _AlphaRange = Mathf.Lerp (_AlphaRange ,0,_missSpeed);
                Set_AlphaRange (_AlphaRange);
            } else {
                deltaX = 1;
                LineState = LineState.end;
                StartCoroutine (ChangeLineStateDown());
            }
            break;
        case LineState.end:
            break;
        }
    }

    IEnumerator ChangeLineStateDown(){
        yield return new WaitForSeconds (IntervalTime);
        LineState = LineState.down;
    }
}

public enum LineState
{
    down,
    miss,
    end
}

包下载：链接: https://pan.baidu.com/s/1vlnljL32A8FezpnXrnTq7w 密码: cf22