Actions
The actions you can pick for "what to do", in the picker's order and with its names. Pick a category on the left and open an entry for its own page. For anything else, Call Udon API under Advanced searches every method and property Udon exposes.
Show / hide
Set ActiveGameObject.SetActiveShow or hide objects.Toggle ActiveGameObject.ToggleActiveFlip each object between shown and hidden.Set Collider EnabledCollider.SetEnabledEnable or disable colliders.Toggle Collider EnabledCollider.ToggleEnabledFlip colliders between enabled and disabled.Set Renderer EnabledRenderer.SetEnabledShow or hide renderers without disabling the object.Toggle Renderer EnabledRenderer.ToggleEnabledFlip renderers between shown and hidden, keeping the object.Set Component EnabledBehaviour.SetEnabledEnable or disable components (Light, Animator, AudioSource, UdonBehaviour, ...).Toggle Component EnabledBehaviour.ToggleEnabledFlip components (Light, AudioSource, ...) between enabled and disabled.