As objects move through a simulation, they create a visible trail in 3D space showing where they have been. This trail fades with time, such that only the more recent positions of the object are shown in its trail.
Trails are on by default in most simulations. To toggle the displayed trails on and off, the user can use the T hotkey, the Trails toggle in the View menu in the bottom bar, or the Trails toggle in the full View Settings Menu. If displayed trails are turned on for the simulation, the trail for an individual object can be toggled on or off using the Trail toggle in the Appearance tab of the object's properties panel.
By default, trails created by objects in a simulation will remain where they were created, relative to the Simulation Origin, until they fade. However, the user can set one object in the simulation to be the trail center, and the trails will remain in place relative to this object instead. In this case the trails will move with the trail center object if it moves relative to the Simulation Grid.
The trail center can be reset to the Simulation Origin via the Clear Trail Center action in the Actions tab of any object in the simulation.
The current simulation trail center is displayed in the full View Settings menu, which also contains controls for setting and resetting the trail center, and changing the trail mode.
Trail Display Settings
Settings related to the width, length, and brightness of trails are located in the full View Settings Menu.