Pausing a game

engine.set_paused(true) holds the tree. A node set to process = "always" keeps its own subtree running, which is what a pause menu is.

process is a key on a node like visible, and the subtree under it inherits the answer:

• pausable stops while paused. The default, and what everything above gets from the root.
• always runs either way. A pause menu, a loading screen, the script that lifts the pause.
• when_paused runs only while paused.
• disabled never runs.
• inherit takes the nearest ancestor's answer.

That one key stops everything that ticks per node:

• Scripts, animation players, tweens, state machines and the timer component.
• Physics is one world and is held whole, so a body under an always node stops with the rest. Godot draws the line in the same place.
• Every script's on_paused(bool) is called when the state changes, the scripts the pause just stopped included.

Slow motion, and the frames between ticks

engine.set_time_scale(0.25) multiplies wall-clock time before the simulation is owed it. Half speed takes half the fixed steps, double takes twice, and each step is still the same length. The cap on catch-up steps scales with it, so fast forward is not quietly clipped. Three settings come with it:

• [window] max_fps caps the loop where vsync does not.
• [time] tick_hz replaces the built-in 60. A recording carries the rate it was made at.
• [time] interpolate draws bodies and fixed_update nodes between steps, so they move on every frame of a 144 Hz display. Off by default: it costs one tick of latency, which a run taking one step per frame pays for nothing.