UE4 径向模糊radiu blur

hlsl代码为：

　　

 float2 ScreenMult = ;
 int TexIndex = ;
 float samples[] = {-0.08,-0.05,-0.03,-0.02,-0.01,0.01,0.02,0.03,0.05,0.08};
 float2 dir = ScreenMult * float2(0.5,0.5) - UV;
 float4 sum = SceneTextureLookup(UV, TexIndex, false);
 float2 pos = float2(0.0,0.0);
 for(int i = ; i<; i++)
 {
     pos = UV + dir * samples[i] * sampleDist;
     max(min(pos, ScreenMult * float2(1.0, 1.0)), float2(0.0,0.0));
     sum += SceneTextureLookup(pos, TexIndex, false);
 }
 sum *= 1.0/11.0;
 return sum;