basically,
screen.x = (object.x - object.y) * 0.5
screen.y = (object.x + object.y) * 0.5
if you want 3D,
screen.x = (object.x - object.y) * 0.5
screen.y = ( (object.x + object.y) * 0.5 - object.z )*0.5
that'S it really. this will turn the x and y axis 45 degrees clockwise.
how you modify the object's x and y is up to you, be it instance variables or behaviors, and they will translate to isometric movements
If you want to know more about my game, there's more information and links inside the game, but I'm not going to talk about it here because I don't want to get banned