Codes

Set up attributes
size (250,250);
background(255);
smooth();



Fine/repetitive lines

for (int b=-60;b<290; b= b+6) {

stroke(82,82,82);
strokeWeight(0);
triangle(270,280,-100,b,290,180);
}

for (int a=0;a<160;a=a+2) {
for (int i=100;i<550;i=i+10) {
stroke(i,a*i);
strokeWeight(1);
line(0,0,250,a);

}
}


for (int b=250;b<16500;b=b+4) {
for (int i=100;i<550;i=i+10) {
stroke(i,b*i);
line(250,192,50,b);
}
}


Continuous circles

int circleSize = 15;
int numCircles = 15;
int circleSpacing = 25;


noStroke();

for (int a=1; a<numCircles; a++) {
for (int b=1; b<numCircles; b++) {

float shiftX= random (0,0);
float shiftY=random(0,0);
float bulge = random (-40,5);
fill(124*a,534-a*b,433*a/b,220);

ellipse(a*circleSpacing+shiftX,b*circleSpacing+shiftY,circleSize+bulge,circleSize+bulge);


}
}


save the file in .png format

save("smooth_pattern.png");