# PL EToys Car demo script

In this demo we will see how EToys supports tile-based visual programming of graphical objects by composing scripts from “tiles” consisting of commands, each of which controls some aspect of the object.

First we draw a hi-tech car with the drawing tool.
We make the front fender a bright red so we can detect when it bumps against something.

We click on the “eye” icon to open the script editor.
Here we see several commands that we can directly execute by clicking on the exclamation mark.

We can define variables if we need them. (We don't for now.)

We can create a script and drag commands into it.
We can let a script run repeatedly in the background using the ticking clock.

Next, we'll draw a race track for the car to drive along.
We'll give it a grassy lawn so the car can detect when it veers too far to the right.

We modify the script to detect when the (red) fender sees the (green) lawn.
It then adjusts the steering back to the right.

Similarly if the car veers onto the concrete, we adjust the steering to the right.