getSeperableBlurMaterial method

dynamic getSeperableBlurMaterial(dynamic kernelRadius)

Implementation

getSeperableBlurMaterial(kernelRadius) {
  return ShaderMaterial({
    "defines": {'KERNEL_RADIUS': kernelRadius, 'SIGMA': kernelRadius},
    "uniforms": {
      'colorTexture': {},
      'texSize': {"value": Vector2(0.5, 0.5)},
      'direction': {"value": Vector2(0.5, 0.5)}
    },
    "vertexShader": """
				varying vec2 vUv;
				void main() {
					vUv = uv;
					gl_Position = projectionMatrix * modelViewMatrix * vec4( position, 1.0 );
				}
    """,
    "fragmentShader": """
				#include <common>
				varying vec2 vUv;
				uniform sampler2D colorTexture;
				uniform vec2 texSize;
				uniform vec2 direction;

				float gaussianPdf(in float x, in float sigma) {
					return 0.39894 * exp( -0.5 * x * x/( sigma * sigma))/sigma;
				}
				void main() {
					vec2 invSize = 1.0 / texSize;
					float fSigma = float(SIGMA);
					float weightSum = gaussianPdf(0.0, fSigma);
					vec3 diffuseSum = texture2D( colorTexture, vUv).rgb * weightSum;
					for( int i = 1; i < KERNEL_RADIUS; i ++ ) {
						float x = float(i);
						float w = gaussianPdf(x, fSigma);
						vec2 uvOffset = direction * invSize * x;
						vec3 sample1 = texture2D( colorTexture, vUv + uvOffset).rgb;
						vec3 sample2 = texture2D( colorTexture, vUv - uvOffset).rgb;
						diffuseSum += (sample1 + sample2) * w;
						weightSum += 2.0 * w;
					}
					gl_FragColor = vec4(diffuseSum/weightSum, 1.0);
				}

    """
  });
}