Membrane

void mainImage( out vec4 fragColor, in vec2 fragCoord ) { vec2 uv = fragCoord/iResolution.xy; vec2 u = uv * 100.; float t = iTime * .37; uv.x += sin(uv.y * 2.) * .1; u.x += sin(uv.x * 4. + t) * 20.; float k = sin(u.x * 3.23) ; k = fract(u.x * .3); vec3 a = vec3(1.1, .05, .2); vec3 b = vec3(1., .4, .547); vec3 c = mix(a, b, k + sin(uv.y) - .5); fragColor = vec4(c,1.); }