透明物体的写法：
一种是clip，写zwrite，好处是不会排序混乱，坏处是没法blend，即透明度测试，透明度测试不能实现半透，只会删除一些片元，看上去像镂空一些面。(解释：设定一个透明度的值，如a，当物体的透明度>a时，按透明处理，直接舍弃，当透明度<a时，按正常物体处理，及深度测试，深度写入，然后深度值要小的物体就被舍弃掉了，不会渲染，也就是透明物体之后的物体不会被渲染了)。
另一种就是blend，不写zwrite，这时候就完全依赖于排序，即透明度混合。（解释：必须先渲染不透明物体，再渲染透明物体，再进行深度测试，被不透明物体挡住的就不会被渲染，挡住不透明物体的，就能正确进行颜色的混合）。
如果你有一个物体里面的面片互相穿插，可以使用两个pass，一个写深度，另外一个做alpha blending。
渲染顺序Queue：
Background 1000 通常用这个队列渲染需要绘制在背景上的物体
Geometry 2000 默认值；大部分物体在这个队列。不透明的物体也在这里
AlphaTest 2450 需要透明度测试物体使用的队列
Transparent 3000 在Geometry和AlphaTest渲染后，再从后往前渲染。透明度混合物体都该用
Overlay 4000 实现叠加效果[如镜头光晕]。任何需要最后渲染的，用这个。
自定义 x 用户可以定义任意值，比如”Queue”=”Geometry+10”
RenderType[将Shader分类，用于Shader替换]：
Opaque 绝大部分不透明的物体都使用这个
Transparent 绝大部分透明的物体、包括粒子特效都使用这个
TransparentCutout蒙皮透明着色器
Background 天空盒都使用这个
Overlay GUI/镜头光晕都使用这个
Alpha Blending指令：
Blend Off 关混合
Blend SrcFactor DstFactor
Blend SrcFactor DstFactor, srcFactorA DstFactorA
Blend {code for SrcFactor片元颜色} {code for DstFactor已经在颜色缓冲中的颜色}
resulting RGBA color：
float4 result = SrcFactor * fragment_output + DstFactor * pixel_color;
One float4(1.0, 1.0, 1.0, 1.0)
Zero float4(0.0, 0.0, 0.0, 0.0)
SrcColor fragment_output
SrcAlpha fragment_output.aaaa
DstColor pixel_color
DstAlpha pixel_color.aaaa
OneMinusSrcColor float4(1.0, 1.0, 1.0, 1.0) - fragment_output
OneMinusSrcAlpha float4(1.0, 1.0, 1.0, 1.0) - fragment_output.aaaa
OneMinusDstColor float4(1.0, 1.0, 1.0, 1.0) - pixel_color
OneMinusDstAlpha float4(1.0, 1.0, 1.0, 1.0) - pixel_color.aaaa pixel_color.aaaa=float4(pixel_color.a, pixel_color.a, pixel_color.a, pixel_color.a)
Blend SrcAlpha OneMinusSrcAlpha float4 result = fragment_output.aaaa * fragment_output + (float4(1.0, 1.0, 1.0, 1.0) - fragment_output.aaaa) * pixel_color
Blend One OneMinusSrcAlpha float4 result = float4(1.0, 1.0, 1.0, 1.0) * fragment_output + (float4(1.0, 1.0, 1.0, 1.0) - fragment_output.aaaa) * pixel_color
Blend One One float4 result = float4(1.0, 1.0, 1.0, 1.0) * fragment_output + float4(1.0, 1.0, 1.0, 1.0) * pixel_color
AlphaTest
Shader "Custom/023_AlphaTest" {
Properties
{
_MainTex ("Base (RGB)", 2D) = "white" {}
_NormalMap("NormalMap",2D) = "Bump"{}
_SpecColor("SpecularColor",Color) = (1,1,1,1)
_Shininess("Shininess",Float) = 10
_Cutoff ("Alpha Cutoff", Range(0, 1)) = 0.5
}
SubShader
{
Tags {"Queue"="AlphaTest" "IgnoreProjector"="True" "RenderType"="TransparentCutout"}
Pass
{
Tags { "LightMode"="ForwardBase" }
CGPROGRAM
#pragma vertex vert
#pragma fragment frag
#include "UnityCG.cginc"
uniform sampler2D _MainTex;
uniform sampler2D _NormalMap;
uniform float4 _SpecColor;
//控制凸起程度
uniform float _Shininess;
uniform float4 _LightColor0;
fixed _Cutoff;
struct VertexOutput
{
float4 pos:SV_POSITION;
float2 uv:TEXCOORD0;
float3 lightDir:TEXCOORD1;
float3 viewDir:TEXCOORD2;
};
VertexOutput vert(appdata_tan v)
{
VertexOutput o;
o.pos = mul(UNITY_MATRIX_MVP,v.vertex);
o.uv = v.texcoord.xy;
//得到Object2TangentMatrix矩阵
//这四行代码可以使用Unity定义的一个宏TANGENT_SPACE_ROTATION来代替
float3 normal = v.normal;
float3 tangent = v.tangent;
float3 binormal= cross(v.normal,v.tangent.xyz) * v.tangent.w;//tangent.w决定第三个坐标轴，值为正负1
float3x3 Object2TangentMatrix = float3x3(tangent,binormal,normal);
//之所以变换到切线空间，是为了减少片段着色器的计算量
o.lightDir = mul(Object2TangentMatrix,ObjSpaceLightDir(v.vertex));
o.viewDir = mul(Object2TangentMatrix,ObjSpaceViewDir(v.vertex));
return o;
}
float4 frag(VertexOutput input):COLOR
{
float3 lightDir = normalize(input.lightDir);
float3 viewDir = normalize(input.viewDir);
float4 encodedNormal = tex2D(_NormalMap,input.uv);
//法线[-1,1],颜色[0,1]
float3 normal = float3(2.0*encodedNormal.ag - 1,0.0);
//保证normal为正
normal.z = sqrt(1 - dot(normal,normal));
float4 texColor = tex2D(_MainTex,input.uv);
clip (texColor.a -_Cutoff*0.2);
float3 ambient = texColor.rgb * UNITY_LIGHTMODEL_AMBIENT.rgb;
float3 diffuseReflection = texColor.rgb * _LightColor0.rgb * max(0,dot(normal,lightDir));
float facing;
if(dot(normal,lightDir)<0)
{
facing = 0;
}
else
{
facing = 1;
}
float3 specularRelection =
_SpecColor.rgb * _LightColor0.rgb * facing * pow(max(0,dot(reflect(-lightDir,normal),viewDir)),_Shininess);
return float4(ambient + diffuseReflection + specularRelection,1);
}
ENDCG
}
}
FallBack "Diffuse"
}
效果图如下：
AlphaBlend
//AlphaBlend
Shader "Custom/024_AlphaBlend" {
Properties
{
_MainTex ("Base (RGB)", 2D) = "white" {}
_NormalMap("NormalMap",2D) = "Bump"{}
_SpecColor("SpecularColor",Color) = (1,1,1,1)
_Shininess("Shininess",Float) = 10
_AlphaScale ("Alpha Scale", Range(0, 1)) = 1
}
SubShader
{
Tags {"Queue"="AlphaTest" "IgnoreProjector"="True" "RenderType"="TransparentCutout"}
Pass
{
Tags { "LightMode"="ForwardBase" }
ZWrite Off
Blend SrcAlpha OneMinusSrcAlpha
//float4 result = fragment_output.aaaa * fragment_output + (float4(1.0, 1.0, 1.0, 1.0) - fragment_output.aaaa) * pixel_color
CGPROGRAM
#pragma vertex vert
#pragma fragment frag
#include "UnityCG.cginc"
uniform sampler2D _MainTex;
uniform sampler2D _NormalMap;
uniform float4 _SpecColor;
//控制凸起程度
uniform float _Shininess;
uniform float4 _LightColor0;
fixed _AlphaScale;
struct VertexOutput
{
float4 pos:SV_POSITION;
float2 uv:TEXCOORD0;
float3 lightDir:TEXCOORD1;
float3 viewDir:TEXCOORD2;
};
VertexOutput vert(appdata_tan v)
{
VertexOutput o;
o.pos = mul(UNITY_MATRIX_MVP,v.vertex);
o.uv = v.texcoord.xy;
//得到Object2TangentMatrix矩阵
//这四行代码可以使用Unity定义的一个宏TANGENT_SPACE_ROTATION来代替
float3 normal = v.normal;
float3 tangent = v.tangent;
float3 binormal= cross(v.normal,v.tangent.xyz) * v.tangent.w;//tangent.w决定第三个坐标轴，值为正负1
float3x3 Object2TangentMatrix = float3x3(tangent,binormal,normal);
//之所以变换到切线空间，是为了减少片段着色器的计算量
o.lightDir = mul(Object2TangentMatrix,ObjSpaceLightDir(v.vertex));
o.viewDir = mul(Object2TangentMatrix,ObjSpaceViewDir(v.vertex));
return o;
}
float4 frag(VertexOutput input):COLOR
{
float3 lightDir = normalize(input.lightDir);
float3 viewDir = normalize(input.viewDir);
float4 encodedNormal = tex2D(_NormalMap,input.uv);
//法线[-1,1],颜色[0,1]
float3 normal = float3(2.0*encodedNormal.ag - 1,0.0);
//保证normal为正
normal.z = sqrt(1 - dot(normal,normal));
float4 texColor = tex2D(_MainTex,input.uv);
//clip (texColor.a -_Cutoff*0.2);
float3 ambient = texColor.rgb * UNITY_LIGHTMODEL_AMBIENT.rgb;
float3 diffuseReflection = texColor.rgb * _LightColor0.rgb * max(0,dot(normal,lightDir));
float facing;
if(dot(normal,lightDir)<0)
{
facing = 0;
}
else
{
facing = 1;
}
float3 specularRelection =
_SpecColor.rgb * _LightColor0.rgb * facing * pow(max(0,dot(reflect(-lightDir,normal),viewDir)),_Shininess);
return float4(ambient + diffuseReflection + specularRelection,min(1,texColor.a*_AlphaScale*50));
}
ENDCG
}
}
FallBack "Diffuse"
}
效果图如下：
One Pass ZWrite,Next Pass AlphaBlend
Shader "Custom/025_AlphaBlendZWrite" {
Properties
{
_MainTex ("Base (RGB)", 2D) = "white" {}
_NormalMap("NormalMap",2D) = "Bump"{}
_SpecColor("SpecularColor",Color) = (1,1,1,1)
_Shininess("Shininess",Float) = 10
_AlphaScale ("Alpha Scale", Range(0, 1)) = 1
}
SubShader
{
Tags {"Queue"="AlphaTest" "IgnoreProjector"="True" "RenderType"="TransparentCutout"}
Pass {
ZWrite On
ColorMask 0 //该pass不写入任何颜色通道
}
Pass
{
Tags { "LightMode"="ForwardBase" }
ZWrite Off
Blend SrcAlpha OneMinusSrcAlpha
CGPROGRAM
#pragma vertex vert
#pragma fragment frag
#include "UnityCG.cginc"
uniform sampler2D _MainTex;
uniform sampler2D _NormalMap;
uniform float4 _SpecColor;
//控制凸起程度
uniform float _Shininess;
uniform float4 _LightColor0;
fixed _AlphaScale;
struct VertexOutput
{
float4 pos:SV_POSITION;
float2 uv:TEXCOORD0;
float3 lightDir:TEXCOORD1;
float3 viewDir:TEXCOORD2;
};
VertexOutput vert(appdata_tan v)
{
VertexOutput o;
o.pos = mul(UNITY_MATRIX_MVP,v.vertex);
o.uv = v.texcoord.xy;
//得到Object2TangentMatrix矩阵
//这四行代码可以使用Unity定义的一个宏TANGENT_SPACE_ROTATION来代替
float3 normal = v.normal;
float3 tangent = v.tangent;
float3 binormal= cross(v.normal,v.tangent.xyz) * v.tangent.w;//tangent.w决定第三个坐标轴，值为正负1
float3x3 Object2TangentMatrix = float3x3(tangent,binormal,normal);
//之所以变换到切线空间，是为了减少片段着色器的计算量
o.lightDir = mul(Object2TangentMatrix,ObjSpaceLightDir(v.vertex));
o.viewDir = mul(Object2TangentMatrix,ObjSpaceViewDir(v.vertex));
return o;
}
float4 frag(VertexOutput input):COLOR
{
float3 lightDir = normalize(input.lightDir);
float3 viewDir = normalize(input.viewDir);
float4 encodedNormal = tex2D(_NormalMap,input.uv);
//法线[-1,1],颜色[0,1]
float3 normal = float3(2.0*encodedNormal.ag - 1,0.0);
//保证normal为正
normal.z = sqrt(1 - dot(normal,normal));
float4 texColor = tex2D(_MainTex,input.uv);
//clip (texColor.a -_Cutoff*0.2);
float3 ambient = texColor.rgb * UNITY_LIGHTMODEL_AMBIENT.rgb;
float3 diffuseReflection = texColor.rgb * _LightColor0.rgb * max(0,dot(normal,lightDir));
float facing;
if(dot(normal,lightDir)<0)
{
facing = 0;
}
else
{
facing = 1;
}
float3 specularRelection =
_SpecColor.rgb * _LightColor0.rgb * facing * pow(max(0,dot(reflect(-lightDir,normal),viewDir)),_Shininess);
return float4(ambient + diffuseReflection + specularRelection,min(1,texColor.a*_AlphaScale*50));
}
ENDCG
}
}
FallBack "Diffuse"
}
效果图如下：
