How to produce a effect like this? Adobe Illustrator

Question

How to produce a effect like this? Adobe Illustrator.

Answer 1

This is called Truchet pattern and can easily be created by using script. Script follows as and rest follow gif tutorial attached. Every time you use this script, effect will be random:

object = app.activeDocument.selection [0] ;

for(j=0; j<40; j++)
{
//make a row
for(i=0; i<40; i++)
  {
    newobject = object.duplicate() ;
    newobject.translate(object.width*(i+1),-object.height*(j+1)) ;
    newobject.rotate(Math.floor(Math.random()*4)*90) ;
  }
}