后期材质（PostProcess Material）+ Custom Node 实现"描边"和"马赛克"效果【UE4】

//input SceneTexSize
//input UV
//input NotUse
//input OutLineSize
//input MaxZ
//input OutLineColor
float3 w=float3(0.2125,0.7154,0.0721);
float2 Sampler[]={float2(-1,-1),float2(-2,0),float2(-1,1),
                    float2(0,-2),float2(0,0),float2(0,2),
                    float2(1,-1),float2(2,0),float2(1,1)};
float2 UVOffset[]={float2(-1,-1),float2(0,-1),float2(1,-1),
                   float2(-1,0),float2(0,0),float2(1,0),
                   float2(-1,1),float2(0,1),float2(1,1),};
float2 Edge=0;
for(int i=0;i<9 ;i++)
{
    Edge+=Sampler[i]*dot(SceneTextureLookup(UV+UVOffset[i]*SceneTexSize*OutLineSize,14,false).xyz,w);
}
//最后的length可以改成1-abs(Edge.x)-abs(Edge.y),这样可以减少运算量
return lerp(
SceneTextureLookup(UV,14,false),OutLineColor,length(Edge));

//input BaseUV 屏幕UV
//intput Tiling
//input Ratio
//input NotUse
float2 UV=BaseUV;
UV*=Tiling;
UV.y*=Ratio;
UV=ceil(UV);
UV/=Tiling;
UV.y/=Ratio;
return SceneTextureLookup(UV,14,false);