[Unreal/Material] Gaussian Blur 구현

노드 구조

Blur_Size 파라미터

값을 조절하면 블러가 적용된다.

 

IsNormal 파라미터

노말맵이라면 체크 해주어야한다.

이유는 https://monggus.tistory.com/375 참고

Custom 코드

// Var

float3 out_color = float3(0.0, 0.0, 0.0);

float Pi = 6.28318530718;

float Directions = 16.0; // BLUR DIRECTIONS (Default 16.0 - More is better but slower)

float Quality = 4.0; // BLUR QUALITY (Default 4.0 - More is better but slower)

float Size = in_size; // BLUR SIZE (Radius)

float2 Radius = Size; // temp

// Blur

for(float d=0.0; d<Pi; d += Pi/Directions)

{

    for(float i = 1.0/Quality; i <= 1.0; i += 1.0/Quality)

    {

        if(in_isNormal != 0) {

            out_color += UnpackNormalMap(Texture2DSample(in_tex, in_texSampler, in_uv+float2(cos(d),sin(d))*Radius*i));

        }

        else {

            out_color += Texture2DSample(in_tex, in_texSampler, in_uv+float2(cos(d),sin(d))*Radius*i);

        }

    }

}

out_color /= Quality * Directions - 15.0;

return out_color;

 

참고 자료

// --- [GLSL] Shadertoy ---

// https://www.shadertoy.com/view/Xltfzj

void mainImage( out vec4 fragColor, in vec2 fragCoord )

{

    float Pi = 6.28318530718; // Pi*2

   

    // GAUSSIAN BLUR SETTINGS {{{

    float Directions = 16.0; // BLUR DIRECTIONS (Default 16.0 - More is better but slower)

    float Quality = 3.0; // BLUR QUALITY (Default 4.0 - More is better but slower)

    float Size = 8.0; // BLUR SIZE (Radius)

    // GAUSSIAN BLUR SETTINGS }}}

   

    vec2 Radius = Size/iResolution.xy;

   

    // Normalized pixel coordinates (from 0 to 1)

    vec2 uv = fragCoord/iResolution.xy;

    // Pixel colour

    vec4 Color = texture(iChannel0, uv);

   

    // Blur calculations

    for( float d=0.0; d<Pi; d+=Pi/Directions)

    {

        for(float i=1.0/Quality; i<=1.0; i+=1.0/Quality)

        {

            Color += texture( iChannel0, uv+vec2(cos(d),sin(d))*Radius*i);      

        }

    }

   

    // Output to screen

    Color /= Quality * Directions - 15.0;

    fragColor =  Color;

}

// --- [HLSL] Blog ---

// https://odederell3d.blog/2021/07/04/ue4-hlsl-texture-sample-quick-tip/

int blur_samples = int(samples * 0.5f);

float3 col = 0.0f;

float2 sample_coords = 0.0f;

for (int i = -blur_samples; i < blur_samples; i ++)

{  

    sample_coords.x = i * (size / blur_samples * 2);

    col += Texture2DSample(tex_in, tex_inSampler, coords + sample_coords ) / (blur_samples * 2);

}

return col;

위 두가지 자료를 참고하여 만든 것이다.