Unity3D Shader实现扫描显示效果

本文实例为大家分享了Unity3D Shader实现扫描显示的具体代码，供大家参考，具体内容如下

通过Shader实现，从左向右的扫描显示，可自定义扫描颜色、宽度、速度。

效果图如下

编辑器界面如下

Shader源码如下

Shader "XM/ScanEffect"
{
Properties
{
_MainTex("Main Tex", 2D) = "white"{}
_lineColor("Line Color", Color) = (0,0,0,0)
_lineWidth("Line width", Range(0, 1.0)) = 0.1
_rangeX("Range X", Range(0,1.0)) = 1.0
}

SubShader
{
Tags {
"Queue" = "Transparent"
}

ZWrite Off
Blend SrcAlpha OneMinusSrcAlpha
Cull back

Pass
{
CGPROGRAM

#pragma vertex vert
#pragma fragment frag

#include "Lighting.cginc"

sampler2D _MainTex;
float4 _MainTex_ST;
float4 _lineColor;
float _lineWidth;
float _rangeX;

struct a2v
{
float4 vertex : POSITION;
float4 texcoord : TEXCOORD0;
};

struct v2f
{
float4 pos : SV_POSITION;
float2 uv : TEXCOORD0;
};

v2f vert(a2v v)
{
v2f o;
o.pos = mul(UNITY_MATRIX_MVP, v.vertex);
o.uv = TRANSFORM_TEX(v.texcoord, _MainTex);
return o;
}

fixed4 frag(v2f i) : SV_TARGET
{
fixed4 col = tex2D(_MainTex, i.uv);

if(i.uv.x > _rangeX)
{
clip(-1);
}
else if (i.uv.x > _rangeX - _lineWidth)
{
float offsetX = i.uv.x - _rangeX +_lineWidth;
fixed xAlpha = offsetX / _lineWidth;
col = col * (1 - xAlpha) + _lineColor * xAlpha;
}

return col;
}

ENDCG
}
}

FallBack "Diffuse"
}

代码调用如下

using UnityEngine;
using System.Collections;
public class ScanEffect : MonoBehaviour
{
//默认扫描线的宽
[Range(0,1)]
public float _defaultLineW = 0.2f;
//扫描的速度
[Range(0, 1)]
public float _showSpeed = 0.02f;

private MeshRenderer _render;

private void Awake()
{
_render = GetComponent<MeshRenderer>();
SetX(0);
SetLineWidth(0);
}

public void SetLineWidth(float val)
{
_render.material.SetFloat("_lineWidth", val);
}
public void SetX(float val)
{
_render.material.SetFloat("_rangeX", val);
}

public void Show()
{
StopCoroutine("Showing");
StartCoroutine("Showing");
}
public void Hide()
{
StopCoroutine("Showing");

SetX(0);
SetLineWidth(0);
}

private IEnumerator Showing()
{
float deltaX = 0;
float deltaWidth = _defaultLineW;

SetX(deltaX);
SetLineWidth(deltaWidth);

while (true)
{
if (deltaX != 1)
{
deltaX = Mathf.Clamp01(deltaX + _showSpeed);
SetX(deltaX);
}
else
{
if (deltaWidth != 0)
{
deltaWidth = Mathf.Clamp01(deltaWidth - _showSpeed);
SetLineWidth(deltaWidth);
}
else
{
break;
}
}
yield return new WaitForEndOfFrame();
}
}

public void OnGUI()
{
if (GUILayout.Button("Show"))
{
Show();
}
if (GUILayout.Button("Hide"))
{
Hide();
}
}
}

来源：https://blog.csdn.net/u012741077/article/details/53386209