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UE3 Home > Kismet Visual Scripting > Kismet Visual Debugger User Guide

Kismet Visual Debugger User Guide


The Kismet Visual Debugger allows users to easily track the flow of Kismet sequence in realtime through the use of breakpoints on sequence objects that pause execution of the game when the sequence objects are activated. The Kismet Visual Debugger is only available when using the editor's Play In Editor functionality.

The Kismet Visual Debugger Window

Enabling and disabling of realtime Kismet debugging is done through the "Toggle Realtime Debugging" button Realtime_Kismet_Debugging.png in the editor's main toolbar.

Realtime debugging cannot be enabled or disabled while Play In Editor is active.

When enabled, if Play In Editor is used, any currently opened Kismet windows will be switched to a "debugger" mode. When Play In Editor is ended, the Kismet windows will be restored to their normal state.

If a Kismet window is closed while Play In Editor is active, Kismet window can be reopened by simply clicking the Kismet button Kismet.png in the editor's main toolbar.


The upper-left corner of the graph panel has an info box containing the current runtime of the game along with an "Execution Paused!" notification when the game is paused.

Active links appear in white and active sequence objects have a white border along with an info box above them that displays how many times they've been activated along with the time the object was last activated.

An orange arrow in the upper-left corner of an object indicates which object the Kismet window is currently paused on.


If Realtime Debugging is enabled, setting a breakpoint on a sequence object in Kismet will cause the game to pause (and focus to be given to the Kismet Visual Debugger window) whenever that sequence action is activated during Play In Editor. The intended purpose of breakpoints is to allow the user to better track the order of events within a Kismet sequence.

Breakpoints can be added to and removed from any sequence actions, conditions or event by right-clicking the object in Kismet's graph panel and selecting either "Set Breakpoint on selected object(s)" or "Remove Breakpoint on selected object(s)" in the context menu.


If multiple sequence objects are selected, breakpoints will be added to or removed from each selected object.

Sequence objects with breakpoints will have a red circle near the upper-left corner of the object.


Breakpoints can also be toggled on and off by holding down the Alt key when left-clicking the mouse on a sequence object.

There's also a toolbar button KIS_ClearBreakpoints.png for clearing all breakpoints in all levels currently open in the editor.

Breakpoints can be added to and removed from sequence objects regardless of whether or not a Kismet window is in debugger mode.

Assuming realtime debugging has been enabled, when a sequence object with a breakpoint is activated while Play In Editor is active, the execution of the game will be paused, and a Kismet window in debugging mode will be opened, if one wasn't already, and the sequence object will be centered in the graph panel of the Kismet window.

Toolbar Buttons

Icon Description
KIS_Pause.png Pause – Pauses game execution (Alt+F7)
KIS_Continue.png Continue – Resumes game execution (Alt+F8)
KIS_Next.png Run to next action – Runs the game until the next sequence object... see details below (Alt+F10)
KIS_Step.png Step through – Increments the game time by one unit of game time / tick (Alt+F9)

The Run To Next button has three different behaviors that can be accessed by right-clicking the button.


"Any" just means it will run to the next activated sequence object. "Downstream" means it will run to the next activated sequence object that is directly downstream from the object that it's currently paused on. And "Selected" means it will run to the next activated sequence object that's currently selected.

Keyboard Shortcuts

From the Kismet window while in debugging mode:
Shortcut Description
Alt+F7 Pause
Alt+F8 Continue
Alt+F9 Step through
Alt+F10 Run to next action

From the Play In Editor window:
Shortcut Description
Shift+F1 Toggles whether, or not, the mouse cursor is locked to the Play In Editor window
Alt+F7 Pause