Pen
pen [▼] is a code block part of the Environment drawer.
Usage
pen [▼](s) adjusts the pen tool. If the pen is down, the agent stamps the terrain at each position as it moves. If the pen is up, the agent does not stamp the terrain.
Syntax
pen [Dropdown: Down/Up]
Nuances
An important difference between pen [▼] and stamp [_] is that pen [▼] allows for continuous marking of the terrain that always follows the agent's movement.