URP透明效果

作者: BacteriumFox | 来源:发表于2021-01-07 10:55 被阅读0次

URP透明效果
URP多光源阴影处理
URP基础纹理
URP多光源处理
URP标准光照模型
URP卡通水体渲染
透明效果
Ⅲ透明效果
URP初试
透明效果_双面渲染透明效果04

URP透明效果

该节我们会实现URP下透明度测试、透明度混合和开启深度写入的透明度混合效果

本系列URP不再阐述具体的效果实现逻辑与公式推导，侧重于URP下对《Shader入门精要》中Demo的复刻。如果对该Shader实现原理层面不太了解，建议移步我之前对《Shader入门精要》一书的学习笔记博客。在此感谢该书作者冯乐乐女神为我们这些新手铺垫了求学之路。

透明度测试

效果图

使用到的语法

在Tags中声明渲染类型为镂空

      "RenderType" = "TransparentCutout"

声明渲染路径为前向渲染

      Tags { "LightMode" = "UniversalForward" }

clip用于剔除透明度低于参数的像素
```
      clip(texColor.a - _Cutoff);
```

完整代码

Shader "URP/AlphaTestWithBothSide"
{
    Properties
    {
        _Color ("Color Tint", Color) = (1, 1, 1, 1)
        _MainTex ("Main Tex", 2D) = "white" { }
        _Cutoff ("Alpha Cutoff", Range(0.0, 1.0)) = 0.5
    }
    SubShader
    {
        //      指定渲染通道使用URP渲染管线                     渲染队列 = 透明度测试       忽略投影                    渲染类型 = 透明镂空
        Tags { "RenderPipeline" = "UniversalRenderPipeline" "Queue" = "AlphaTest" "IgnoreProjector" = "True" "RenderType" = "TransparentCutout" }
        
        Pass
        {
            Tags { "LightMode" = "UniversalForward" }
            
            // 关闭渲染剔除
            Cull Off
            
            HLSLPROGRAM
            
            #pragma vertex vert
            #pragma fragment frag

            // 引用URP函数库
            #include "Packages/com.unity.render-pipelines.universal/ShaderLibrary/Core.hlsl"
            #include "Packages/com.unity.render-pipelines.universal/ShaderLibrary/Lighting.hlsl"
            #include "Packages/com.unity.render-pipelines.core/ShaderLibrary/SpaceTransforms.hlsl"
            
            // 声明纹理
            TEXTURE2D(_MainTex);
            // 声明采样器
            SAMPLER(sampler_MainTex);
            
            CBUFFER_START(UnityPerMaterial)
            half4 _Color;
            float4 _MainTex_ST;
            half _Cutoff;
            CBUFFER_END
            
            struct a2v
            {
                float4 vertex: POSITION;
                float3 normal: NORMAL;
                float4 texcoord: TEXCOORD0;
            };
            
            struct v2f
            {
                float4 pos: SV_POSITION;
                float3 worldNormal: TEXCOORD0;
                float3 worldPos: TEXCOORD1;
                float2 uv: TEXCOORD2;         
            };
            
            v2f vert(a2v v)
            {
                v2f o;
                // 初始化变量
                ZERO_INITIALIZE(v2f, o);
                
                o.pos = TransformObjectToHClip(v.vertex.xyz);
                
                o.worldNormal = TransformObjectToWorldNormal(v.normal);
                
                o.worldPos = TransformObjectToWorld(v.vertex.xyz);
                
                o.uv = TRANSFORM_TEX(v.texcoord, _MainTex);
          
                return o;
            }
            
            half4 frag(v2f i): SV_Target
            {
                half3 worldNormal = normalize(i.worldNormal);
                half3 worldLightDir = normalize(TransformObjectToWorldDir(_MainLightPosition.xyz));
                
                half4 texColor = SAMPLE_TEXTURE2D(_MainTex, sampler_MainTex, i.uv);
                // 使用clip函数剔除透明像素
                clip(texColor.a - _Cutoff);
                
                half3 albedo = texColor.rgb * _Color.rgb;
                
                half3 ambient = _GlossyEnvironmentColor * albedo;
                
                half3 diffuse = _MainLightColor.rgb * albedo * max(0, dot(worldNormal, worldLightDir));
                
                
                return half4(ambient + diffuse, 1.0);
            }
            
            ENDHLSL
            
        }
    }
    FallBack "Packages/com.unity.render-pipelines.universal/SimpleLit"
}

透明度混合双面渲染

效果

使用到的语法

暂无新语法

完整代码

与CG实现下不同的是，在URP下无需用双Pass进行正反面渲染，直接关闭渲染剔除即可实现对透明物体的双面渲染

Shader "URP/AlphaBlendWithBothSide"
{
    Properties
    {
        _Color ("Color Tint", Color) = (1, 1, 1, 1)
        _MainTex ("Main Tex", 2D) = "white" { }
        _AlphaScale ("Alpha Scale", Range(0, 1)) = 1
    }
    SubShader
    {
        //      指定渲染通道使用URP渲染管线                     渲染队列 = 透明度混合       忽略投影                    渲染类型 = 透明物体
        Tags { "RenderPipeline" = "UniversalRenderPipeline" "Queue" = "Transparent" "IgnoreProjector" = "True" "RenderType" = "Transparent" }
        
        Pass
        {
            Tags { "LightMode" = "UniversalForward" }
            // 关闭渲染剔除
            Cull Off
            // 关闭深度写入
            ZWrite Off
            // 混合因子设置
            Blend SrcAlpha OneMinusSrcAlpha
            
            HLSLPROGRAM
            
            #pragma vertex vert
            #pragma fragment frag
            
            // 引用URP函数库
            #include "Packages/com.unity.render-pipelines.universal/ShaderLibrary/Core.hlsl"
            #include "Packages/com.unity.render-pipelines.universal/ShaderLibrary/Lighting.hlsl"
            #include "Packages/com.unity.render-pipelines.core/ShaderLibrary/SpaceTransforms.hlsl"
            
            // 声明纹理
            TEXTURE2D(_MainTex);
            // 声明采样器
            SAMPLER(sampler_MainTex);
            
            CBUFFER_START(UnityPerMaterial)
            half4 _Color;
            float4 _MainTex_ST;
            half _AlphaScale;
            CBUFFER_END
            
            struct a2v
            {
                float4 vertex: POSITION;
                float3 normal: NORMAL;
                float4 texcoord: TEXCOORD0;
            };
            
            struct v2f
            {
                float4 pos: SV_POSITION;
                float3 worldNormal: TEXCOORD0;
                float3 worldPos: TEXCOORD1;
                float2 uv: TEXCOORD2;
            };
            
            v2f vert(a2v v)
            {
                v2f o;
                // 初始化变量
                ZERO_INITIALIZE(v2f, o);
                
                o.pos = TransformObjectToHClip(v.vertex.xyz);
                
                o.worldNormal = TransformObjectToWorldNormal(v.normal);
                
                o.worldPos = TransformObjectToWorld(v.vertex.xyz);
                
                o.uv = TRANSFORM_TEX(v.texcoord, _MainTex);
                
                return o;
            }
            
            half4 frag(v2f i): SV_Target
            {
                half3 worldNormal = normalize(i.worldNormal);
                half3 worldLightDir = normalize(TransformObjectToWorldDir(_MainLightPosition.xyz));
                
                half4 texColor = SAMPLE_TEXTURE2D(_MainTex, sampler_MainTex, i.uv);
                
                half3 albedo = texColor.rgb * _Color.rgb;
                
                half3 ambient =_GlossyEnvironmentColor.xyz * albedo;
                
                half3 diffuse = _MainLightColor.rgb * albedo * max(0, dot(worldNormal, worldLightDir));
                
                return half4(ambient + diffuse, texColor.a * _AlphaScale);
            }            
            ENDHLSL            
        }        
    }
    FallBack "Packages/com.unity.render-pipelines.universal/SimpleLit"
}

开启深度写入的透明度混合

效果

使用到的语法

暂无新语法

完整代码

与CG实现下不同的是，在URP下无需额外增加一个Pass去单独渲染深度缓冲区，可以直接开启深度写入

Shader "URP/AlphaBlendingWithZWrite"
{
    Properties
    {
        _Color ("Color Tint", Color) = (1, 1, 1, 1)
        _MainTex ("Main Tex", 2D) = "white" { }
        _AlphaScale ("Alpha Scale", Range(0, 1)) = 1
    }
    SubShader
    {
        //         指定渲染通道使用URP渲染管线                  渲染队列 = 透明度混合        忽略投影 = Ture             渲染类型 = 透明物体
        Tags { "RenderPipeline" = "UniversalRenderPipeline" "Queue" = "Transparent" "IgnoreProjector" = "True" "RenderType" = "Transparent" }
        
        /*
        // 添加额外的Pass，仅用于渲染到深度缓冲区
        Pass
        {
            // 开启深度写入
            ZWrite On
            // 用于控制Pass不写入任何颜色通道
            ColorMask 0
        }
        */

        Pass
        {
            Tags { "LightMode" = "UniversalForward" }
            // 关闭渲染剔除
            Cull Off
            ZWrite On
            Blend SrcAlpha OneMinusSrcAlpha
            
            HLSLPROGRAM
            
            #pragma vertex vert
            #pragma fragment frag
            
            // 引用URP函数库
            #include "Packages/com.unity.render-pipelines.universal/ShaderLibrary/Core.hlsl"
            #include "Packages/com.unity.render-pipelines.universal/ShaderLibrary/Lighting.hlsl"
            #include "Packages/com.unity.render-pipelines.core/ShaderLibrary/SpaceTransforms.hlsl"
            
            // 声明纹理
            TEXTURE2D(_MainTex);
            // 声明采样器
            SAMPLER(sampler_MainTex);
            
            CBUFFER_START(UnityPerMaterial)
            half4 _Color;
            float4 _MainTex_ST;
            half _AlphaScale;
            CBUFFER_END
            
            struct a2v
            {
                float4 vertex: POSITION;
                float3 normal: NORMAL;
                float4 texcoord: TEXCOORD0;
            };
            
            struct v2f
            {
                float4 pos: SV_POSITION;
                float3 worldNormal: TEXCOORD0;
                float3 worldPos: TEXCOORD1;
                float2 uv: TEXCOORD2;
            };
            
            v2f vert(a2v v)
            {
                v2f o;
                // 初始化变量
                ZERO_INITIALIZE(v2f, o);
                
                o.pos = TransformObjectToHClip(v.vertex.xyz);
                
                o.worldNormal = TransformObjectToWorldNormal(v.normal);
                
                o.worldPos = TransformObjectToWorld(v.vertex.xyz);
                
                o.uv = TRANSFORM_TEX(v.texcoord, _MainTex);
                
                return o;
            }
            
            half4 frag(v2f i): SV_Target
            {
                half3 worldNormal = normalize(i.worldNormal);
                half3 worldLightDir = normalize(TransformObjectToWorldDir(_MainLightPosition.xyz));
                
                half4 texColor = SAMPLE_TEXTURE2D(_MainTex, sampler_MainTex, i.uv);
                
                half3 albedo = texColor.rgb * _Color.rgb;
                
                half3 ambient = _GlossyEnvironmentColor.xyz * albedo;
                
                half3 diffuse = _MainLightColor.rgb * albedo * max(0, dot(worldNormal, worldLightDir));
                
                return half4(ambient + diffuse, texColor.a * _AlphaScale);
            }
            
            ENDHLSL
            
        }
    }
    FallBack "Packages/com.unity.render-pipelines.universal/SimpleLit"
}