Unityshader学习记录（透明效果1）

感悟&＃xff1a;

1、首先进行深度测试&＃xff08;是否开启&＃xff09;和深度检验&＃xff0c;然后写入颜色缓冲&＃xff0c;深度缓冲&＃xff08;深度缓冲要看是否开启深度写入&＃xff09;

2、颜色缓冲和深度写入是两个不同的东西&＃xff0c;每次得到结果会写入颜色缓冲中

3、透明物体进行排序时&＃xff0c;都考虑到有些情况会有循环覆盖物体遮挡的问题&＃xff0c;但是还是没什么比较通用的解决方法&＃xff08;推荐的方法是分割网格&＃xff09;&＃xff0c;所以这就是渲染透明物体大家都谨慎的原因吧。&＃xff08;就像明知道有个渣男&＃xff0c;却说忍忍吧的感觉&＃xff09;

总结&＃xff1a;

透明效果可以通过两种方式实现&＃xff1a;透明度测试、透明度混合。在实际应用中&＃xff0c;我们大多选择透明度混合。

透明度测试&＃xff1a;只要一个片元的透明度不满足条件&＃xff0c;那么它会被舍弃。满足条件的会按照普通的不透明物体进行处理。

透明度混合&＃xff1a;使用当前片元的透明度作为混合因子&＃xff0c;与已经存储在颜色缓冲中的颜色值进行混合&＃xff0c;得到新的颜色。但是透明度混合需要关闭深度写入&＃xff0c;不关闭深度测试。

透明度测试代码&＃xff1a;&＃xff08;使用clip函数&＃xff09;

Shader "Custom/AlphaTest" { Properties {_Color ("Color Tint", Color) &＃61; (1, 1, 1, 1)_MainTex ("Main Tex", 2D) &＃61; "white" {}_Cutoff ("Alpha Cutoff", Range(0, 1)) &＃61; 0.5}SubShader {Tags {"Queue"&＃61;"AlphaTest" "IgnoreProjector"&＃61;"True" "RenderType"&＃61;"TransparentCutout"}Pass {Tags { "LightMode"&＃61;"ForwardBase" }CGPROGRAM#pragma vertex vert#pragma fragment frag#include "Lighting.cginc"fixed4 _Color;sampler2D _MainTex;float4 _MainTex_ST;fixed _Cutoff;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;o.pos &＃61; UnityObjectToClipPos(v.vertex);o.worldNormal &＃61; UnityObjectToWorldNormal(v.normal);o.worldPos &＃61; mul(unity_ObjectToWorld, v.vertex).xyz;o.uv &＃61; TRANSFORM_TEX(v.texcoord, _MainTex);return o;}fixed4 frag(v2f i) : SV_Target {fixed3 worldNormal &＃61; normalize(i.worldNormal);fixed3 worldLightDir &＃61; normalize(UnityWorldSpaceLightDir(i.worldPos));fixed4 texColor &＃61; tex2D(_MainTex, i.uv);// Alpha test通过判断clip内的值若小于0对fragment进行discardclip (texColor.a - _Cutoff);fixed3 albedo &＃61; texColor.rgb * _Color.rgb;fixed3 ambient &＃61; UNITY_LIGHTMODEL_AMBIENT.xyz * albedo;fixed3 diffuse &＃61; _LightColor0.rgb * albedo * max(0, dot(worldNormal, worldLightDir));return fixed4(ambient &＃43; diffuse, 1.0);}ENDCG}} FallBack "Transparent/Cutout/VertexLit"
}

透明度混合代码&＃xff1a;使用blend命令

Shader "Custom/AlphaBlend" {Properties {_MainTex ("Main Tex", 2D) &＃61; "white" {}_AlphaScale ("Alpha Scale", Range(0, 1)) &＃61; 1}SubShader {Tags {"Queue"&＃61;"Transparent" "IgnoreProjector"&＃61;"True" "RenderType"&＃61;"Transparent"}Pass {Tags { "LightMode"&＃61;"ForwardBase" }ZWrite OffBlend SrcAlpha OneMinusSrcAlphaCGPROGRAM#pragma vertex vert#pragma fragment frag#include "Lighting.cginc"sampler2D _MainTex;float4 _MainTex_ST;fixed _AlphaScale;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;o.pos &＃61; UnityObjectToClipPos(v.vertex);o.worldNormal &＃61; UnityObjectToWorldNormal(v.normal);o.worldPos &＃61; mul(unity_ObjectToWorld, v.vertex).xyz;o.uv &＃61; TRANSFORM_TEX(v.texcoord, _MainTex);return o;}fixed4 frag(v2f i) : SV_Target {fixed3 worldNormal &＃61; normalize(i.worldNormal);fixed3 worldLightDir &＃61; normalize(UnityWorldSpaceLightDir(i.worldPos));fixed4 texColor &＃61; tex2D(_MainTex, i.uv);fixed3 albedo &＃61; texColor.rgb;fixed3 ambient &＃61; UNITY_LIGHTMODEL_AMBIENT.xyz * albedo;fixed3 diffuse &＃61; _LightColor0.rgb * albedo * max(0, dot(worldNormal, worldLightDir));return fixed4(ambient &＃43; diffuse, texColor.a * _AlphaScale);}ENDCG}} FallBack "Transparent/VertexLit"
}