In The Machinery, we make a distinction between simulating and editing. When you are editing, you see a static view of the scene. All the runtime behaviors like physics, animation, destruction, entity spawning, etc are disabled. (Editing the scene with everything moving around would be very tricky.)

In contrast, when you are simulating or running, all the dynamic behaviors are enabled. This allows you to see the runtime behavior of your entities. If you are building a game, the simulation mode would correspond to running the game.

To simulate a scene, open a scene in the Simulate tab.

Simulate tab.

You can use the controls in the tab to pause, play, or restart the simulation or change the simulation speed. Note that if you haven't added any simulation components to the scene, the Simulate tab will be just as static as the Scene tab. In order to get something to happen, you need to add some runtime components.

The Entity Graph gives you a visual scripting language for controlling entity behavior. It will be described in the next section.

You can launch the engine in simulation mode from the command line:

the-machinery.exe --load-project project.the_machinery --simulate scene

Here project.the_machinery should be the name of your project file and scene the name of the entity you want to simulate. This will open a window with just the Simulate tab, simulating the scene that you specified.