Shader学习笔记4

前两篇写的大多是表面着色器（SurfaceShader），有官方的，网上的，自己写的。自己看着都乱，当做仓库用吧。。。

然后就研究到了顶点和片段着色器，发现很自由，功能很多，但是不能处理光照。还有屏幕特效什么的特别炫酷，可惜我太菜看不懂。写完这篇博客，Shader也要停一下，需要消化一段时间，以后也许会写一些Shader的插件，原理，实现技巧什么的，嗯，就这么多。下面就是2个我感觉常用的屏幕特效：

屏幕特效

摄像机灰度（死亡视角）

在Camera中设置脚本，设置Material ---mat

调用回调

OnRenderImage（RenderTexuture source,RenderTexture dest）{

      

Graphics.Blit(source, dest, mat);

}

_MainTex 不需要赋值，_Num控制灰度，0是不灰，1是灰，可以实现从死亡视角转化为正常视角

Shader"Custom/MatShader"

{

                Properties

                {

                                //主纹理

                                _MainTex ("Albedo (RGB)",2D) ="white"{}

                                _Num("Num",Range(0,1))=0

                }

                SubShader

                {

                                Tags{"RenderType"="Opaque"}

                                LOD200

       Pass{

       CGPROGRAM

                                #pragma vertex vert

                                #pragma fragment frag

                                #include "UnityCG.cginc"

                                sampler2D_MainTex;

                                fixed_Num;

       voidvert(inoutappdata_basev)

        {

             v.vertex =mul(UNITY_MATRIX_MVP,v.vertex);

        }

       fixed4frag(appdata_basev):Color

        {

            fixed4c =tex2D(_MainTex,v.texcoord);

            fixedval = c.r*0.3+c.g*0.59+c.b*0.11;

            fixed4now =fixed4(val,val,val,1);

            returnlerp(c,now,_Num);

        }

       

       ENDCG

        }

         }

                //备胎为漫反射

                FallBack"Diffuse"

}

径向模糊

•   步骤一：定义径向模糊的中心点，通常取图像的正中心点。
•   步骤二：计算采样像素与中心点的距离，根据距离确定偏移程度，即离中心点越远，偏移量越大。
•   步骤三：将采样点的颜色值做平均求和。

Shader"径向模糊Shader"{

                Properties{

                                _MainTex("纹理",2D)="while"{}

                                _Level("强度",Range(0,100))=10

                }

                SubShader{

                                Pass

                                {

                                  CGPROGRAM

                                  #pragma vertex vert

                                  #pragma fragment frag

                                  #include "unitycg.cginc"

                                  sampler2D_MainTex;

                                  float_Level;

                                   structv2f{

                                                                fixed4vertex:POSITION;

                                                                fixed2uv:TEXCOORD;

                                                };

                                                v2f vert(appdata_basev){

                                                                v2f o;

                                                                o.vertex=mul(UNITY_MATRIX_MVP,v.vertex);

                                                                o.uv=v.texcoord;

                                                                returno;

                                                }

                                                fixed4frag(v2f i):COLOR{ 

                                                                fixed4c;

                                                                fixed2center=fixed2(.5,.5);

                                                                fixed2uv=i.uv-center;

                                                                fixed3c1=fixed3(0,0,0);

                                                                for(fixedj=0;j<_Level;j++){

                                                                                c1+=tex2D(_MainTex,uv*(1-0.01*j)+center).rgb;

                                                                }

                                                                c.rgb=c1/_Level;

                                                                c.a=1;

                                                                returnc;

                                                }

                                  ENDCG

                                }

                }

}