未用平滑的发光环 shader

转载自： http://glslsandbox.com/e#44852.0

#ifdef GL_ES
precision mediump float;
#endif


#extension GL_OES_standard_derivatives : enable


uniform float time;
uniform vec2 resolution;


void main( void ) {
vec2 position = ((gl_FragCoord.xy / resolution.xy) * 2. - 1.) * vec2(resolution.x / resolution.y, 1.0);
vec2 pos = gl_FragCoord.xy / resolution.xy * vec2(resolution.x / resolution.y, 1.);

float d = abs( length(pos* abs(1.2)) - 0.50 * abs(1.2)) * 6.0;



gl_FragColor += vec4(0.08/d, 0.04 / d, 0.02 / d, 1.0
                                   );
}