[游戏开发]Unity3D开发之在表面着色器shader中使用顶点着色器制造流光效果

先上流光效果。

变动的是世界坐标x值。当顶点世界坐标靠近变动值，则在附近取流光贴图颜色值附加到物体上。

首先，我们需要在使用shader模型位置处加上vertex:Myvert 后面名字是顶点着色器函数名字

#pragma surface surf Lambert alpha:fade keepalpha noshadow vertex:Myvert

然后编写顶点着色器片段。这里在结构体处增加了世界坐标。

        struct Input
		{
			float2 uv_texcoord;
			float3 worldSpacePos;
		};
        void Myvert(inout appdata_full v, out Input i)
        {
            UNITY_INITIALIZE_OUTPUT(Input, i);
            i.worldSpacePos = mul(unity_ObjectToWorld, v.vertex);
        }

然后就可以在表面着色器片段中编写自己的需求了。

整体代码如下：

Shader "Map-base"
{
	Properties
	{
		_Color("_Color", Color) = (0,0,0,1)
		_Normal("Normal", 2D) = "white" {}
		[HDR]_linecolor("line-color", Color) = (0,0,0,0)
		_linemap("line-map", 2D) = "white" {}
		[HideInInspector] _texcoord( "", 2D ) = "white" {}
		[HideInInspector] __dirty( "", Int ) = 1
		_FlowX("_FlowX",float)=0
		_FlowTex("_FlowTex",2D)="white" {}
		_FlowWidth("_FlowWidth",Range(0.01,1))=1
	}

	SubShader
	{
		Tags{ "RenderType" = "Transparent"  "Queue" = "Transparent+100" "IgnoreProjector" = "True" "IsEmissive" = "true"  }
		Cull Back
		CGPROGRAM
		#include "UnityStandardUtils.cginc"
		#pragma target 3.0
		#pragma surface surf Lambert alpha:fade keepalpha noshadow vertex:Myvert
		struct Input
		{
			float2 uv_texcoord;
			float3 worldSpacePos;
		};

		uniform sampler2D _Normal;
		uniform float4 _Normal_ST;
		uniform float4 _Color;
		uniform float4 _linecolor;
		uniform sampler2D _linemap;
		uniform float4 _linemap_ST;
		uniform float _FlowX;
		uniform sampler2D _FlowTex;
		uniform float _FlowWidth;



		void Myvert(inout appdata_full v, out Input i)
        {
            UNITY_INITIALIZE_OUTPUT(Input, i);
            i.worldSpacePos = mul(unity_ObjectToWorld, v.vertex);
        }

		void surf( Input i , inout SurfaceOutput o )
		{
			float2 uv_Normal = i.uv_texcoord * _Normal_ST.xy + _Normal_ST.zw;
			o.Normal = UnpackScaleNormal( tex2D( _Normal, uv_Normal ), 2.0 );
			float2 uv_linemap = i.uv_texcoord * _linemap_ST.xy + _linemap_ST.zw;
			o.Emission = ( _linecolor * tex2D( _linemap, uv_linemap ).a ).rgb;
			float d1=i.worldSpacePos.x-_FlowX;
			fixed4 c=fixed4(0,0,0,1);
			if(abs(d1)>_FlowWidth/2)
				c=fixed4(0,0,0,1);
			else c=tex2D(_FlowTex, fixed2(0.5+d1/_FlowWidth,1));
			o.Albedo = _Color.rgb+c.rgb;
			o.Alpha = _Color.a*c.a;
		}

		ENDCG
	}
	CustomEditor "ASEMaterialInspector"
}