Shader—双面渲染

1、双面渲染

Shader " DoubleSideShader" {
              Properties {
               //正面5个参数
                    _Color ("Main Color", Color) = (1,1,1,1)
                     _SpecColor ("Specular Color", Color) = (0.5, 0.5, 0.5, 1)
                     _Shininess ("Shininess", Range (0.03, 1)) = 0.078125
                     _MainTex ("Base (RGB) Gloss (A)", 2D) = "white" {}
                    _BumpMap ("Normalmap", 2D) = "bump" {}
                //反面拷贝 改名 也是5个
                    _BackColor ("Back Main Color", Color) = (1,1,1,1)
                    _BackSpecColor ("Back Specular Color", Color) = (0.5, 0.5, 0.5, 1)
                    _BackShininess ("Back Shininess", Range (0.03, 1)) = 0.078125
                    _BackMainTex ("Back Base (RGB) Gloss (A)", 2D) = "white" {}
                    _BackBumpMap ("Back Normalmap", 2D) = "bump" {}
                }
                SubShader {
                Tags { "RenderType"="Opaque" }
                    LOD 400
                    Cull back
                //开始渲染正面    
                CGPROGRAM
                //表明是surface渲染方式 主渲染程序是surf 光照模型是BLinnPhong
                #pragma surface surf BlinnPhong              
               sampler2D _MainTex;
               sampler2D _BumpMap;
                fixed4 _Color;
                half _Shininess;
                
                struct Input {
                    float2 uv_MainTex;
                    float2 uv_BumpMap;
                };            
                void surf (Input IN, inout SurfaceOutput o) {
                    fixed4 tex = tex2D(_MainTex, IN.uv_MainTex);
                   o.Albedo = tex.rgb * _Color.rgb;
                    o.Gloss = tex.a;
                    o.Alpha = tex.a * _Color.a;
                    o.Specular = _Shininess;
                   o.Normal = UnpackNormal(tex2D(_BumpMap, IN.uv_BumpMap));}
                ENDCG      
                    Cull front
                //开始渲染反面 其实和就是拷贝了一份正面渲染的代码 除了变量名要改    
                CGPROGRAM
             #pragma surface surf BlinnPhong 
                sampler2D _BackMainTex;
                sampler2D _BackBumpMap;
                fixed4 _BackColor;
                half _BackShininess;
                struct Input 
              {
                    float2 uv_BackMainTex;
                    float2 uv_BackBumpMap;
              };
                
                void surf (Input IN, inout SurfaceOutput o) {
                     fixed4 tex = tex2D(_BackMainTex, IN.uv_BackMainTex);
                     o.Albedo = tex.rgb * _BackColor.rgb;
                   o.Gloss = tex.a;
                    o.Alpha = tex.a * _BackColor.a;
                     o.Specular = _BackShininess;
                     o.Normal = UnpackNormal(tex2D(_BackBumpMap, IN.uv_BackBumpMap));}
                 ENDCG
                }
                 FallBack "Specular"
                }

2、旗帜飘扬

/ Upgrade NOTE: replaced '_Object2World' with 'unity_ObjectToWorld'
// Upgrade NOTE: replaced 'mul(UNITY_MATRIX_MVP,*)' with 'UnityObjectToClipPos(*)'

Shader "Demo_Flag/Flag"  // 旗帜飘动
{
    Properties
    {
        _MainTex("Main Tex", 2D) = "white" {}                         //主纹理
    _FlagColor("Flag Color", Color) = (1, 1, 1, 1)                //旗子颜色
        _Frequency("Frequency", float) = 5                            //波动频率
        _AmplitudeStrength("Amplitude Strength", float) = 5          // 振幅强度
        _InvWaveLength("Inverse Wave Length", float) = 1             //波长的倒数（_InvWaveLength越小，波长越大）
        _Fold("Fold", Range(0.0, 2.0)) = 0.5                         //旗帜褶皱程度
    }
        SubShader
    {
        // Need to disable batching because of the vertex animation
        Tags{ "DisableBatching" = "True" "RenderType" = "Opaque" }

        Pass
    {
        Tags{ "LightMode" = "ForwardBase" }

        Cull Off

        CGPROGRAM
#pragma vertex vert
#pragma fragment frag

#include "UnityCG.cginc"

        sampler2D _MainTex;
    float4 _MainTex_ST;
    float4 _FlagColor;
    float _Frequency;
    float _AmplitudeStrength;
    float _InvWaveLength;
    float _Fold;

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

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

    v2f vert(a2v v)
    {
        v2f o;
        o.uv = v.texcoord.xy;
        float4 offset;
        // 初始化顶点偏移量
        offset.xyzw = float4(0.0, 0.0, 0.0, 0.0);
        // 计算偏移之前的顶点位置
        float4 v_before = mul(unity_ObjectToWorld, v.vertex);
        // 我们只希望对顶点的 Y 方向进行偏移（正弦型函数y=Asin(ωx+φ)+b）
        offset.y = _AmplitudeStrength * sin(_Frequency * _Time.y + (v_before.x + v_before.y* _Fold) * _InvWaveLength) * o.uv.x;

        //我们只需要把偏移量添加到顶点位置上，再进行正常的顶点变换即可
        o.pos = UnityObjectToClipPos(v.vertex + offset);

        o.uv = TRANSFORM_TEX(v.texcoord, _MainTex);
        return o;
    }

    fixed4 frag(v2f i) : SV_Target
    {
        fixed4 col = tex2D(_MainTex, i.uv);
    col.rgb *= _FlagColor.rgb;
    return col;
    }
        ENDCG
    }
    }
        FallBack "VertexLit"
}