Command System

Unreal Engine 4 has some built-in commands to help game development. These commands can be typed into a built-in console. Using these commands, a developer can profile the game performance and view debug information. To invoke the built-in console of a game, type the ` key (the key above tab).

UnrealCV provides commands useful for computer vision researchers. What is more, these commands can be used by an external program. A built-in command can also be used using the special command vrun.

Command cheatsheet

See this ipython notebook to see an imcomplete demo of available commands.

1. Camera operation

See Source/UnrealCV/Private/Commands/CameraHandler.h(.cpp) for more details.

vget /camera/[id]/location

(v0.2) Get camera location [x, y, z]

vget /camera/[id]/rotation

(v0.2) Get camera rotation [pitch, yaw, roll]

vset /camera/[id]/location [x] [y] [z]

(v0.2) Set camera location [x, y, z]

vset /camera/[id]/rotation [pitch] [yaw] [roll]

(v0.2) Set camera rotation [pitch, yaw, roll]

vget /camera/[id]/[viewmode]

(v0.2) Get [viewmode] from the [id] camera, for example: vget /camera/0/depth

vget /camera/[id]/[viewmode] [filename]

(v0.2) Same as the above, with an extra parameter for filename


Filename is where the file will be stored.


vget /camera/0/lit lit.png

vget /camera/[id]/[viewmode] [format]

(v0.3.7) Support binary data format


If only file format is specified, the binary data will be returned through socket instead of being saved as a file.


vget /camera/0/lit png

vget /camera/[id]/object_mask

(v0.2) The object mask is captured by first switching the viewmode to object_mask mode, then take a screenshot

vset /viewmode [viewmode]

(v0.2) Set ViewMode to (lit, normal, depth, object_mask)

vget /viewmode

(v0.2) Get current ViewMode

vget /camera/[id]/pose

(v0.3.10) Get camera location [x, y, z] and rotation [pitch, yaw, roll]

vset /camera/[id]/pose [x] [y] [z] [pitch] [yaw] [roll]

(v0.3.10) Teleport camera to location [x, y, z] and rotation [pitch, yaw, roll]

vget /camera/[uint]/horizontal_fieldofview

(v0.3.10) Get camera horizontal field of view. This cmd is deprecated, use vget /camera/[uint]/fov instead (v0.4.0).

vset /camera/[uint]/horizontal_fieldofview [FOV]

(v0.3.10) Set camera horizontal field of view. This cmd is deprecated, use vset /camera/[uint]/fov [FOV] instead (v0.4.0).

vget /camera/[uint]/vis_depth npy


vget /camera/[uint]/plane_depth npy


vget /cameras

(v0.4.0) List all cameras in the scene

vset /cameras/spawn

(v0.4.0) Spawn a new camera

2. Object interaction

See Source/UnrealCV/Private/Commands/ObjectHandler.h(.cpp) for more details

vget /objects

(v0.2) Get the name of all objects

vget /object/[obj_name]/color

(v0.2) Get the labeling color of an object (used in object instance mask)

vset /object/[obj_name]/color [r] [g] [b]

(v0.2) Set the labeling color of an object

vset /object/[str]/show

(v0.3.10) Show object

vset /object/[str]/hide

(v0.3.10) Hide object

vset /objects/spawn [class_name] [obj_name]

(v0.4.0) Spawn an object with class name and object name. It can also be used to create a new camera, for example:

  • vset /objects/spawn FusionCameraActor Cam_1 - create a new camera named Cam_1

  • vset /objects/spawn StereoCameraActor StereoCam_1 - create a new stereo camera named StereoCam_1

vset /object/[obj_name]/destroy

(v0.4.0) Destroy object

vset /object/[obj_name]/name [new_obj_name]

(v0.4.0) Rename object

vget /object/[obj_name]/scale

(v0.4.0) Get object scale

vset /object/[str]/scale [x] [y] [z]

(v0.4.0) Set object scale

vget /object/[str]/bounds

(v0.4.0) Get object bounds in the world coordinate, format is [minx, y, z, maxx, y, z]

3. Plugin commands

See Source/UnrealCV/Private/Commands/PluginHandler.h(.cpp) for more details.

vget /unrealcv/status

(v0.2) Get the status of UnrealCV plugin

vget /unrealcv/help

(v0.2) List all available commands and their help message

4. Action commands

See Source/UnrealCV/Private/Commands/ActionHandler.h(.cpp)

vset /action/keyboard [key_name] [delta]

(v0.3.6) Valid key_name can be found in here

vset /action/game/pause

(v0.3.10) Pause the game

vset /action/game/level [level_name]

(v0.3.10) Open a new level

vset /action/input/enable

(v0.3.10) Enable input

vset /action/input/disable

(v0.3.10) Disable input

vset /action/eyes_distance [eye_distance]

(v0.3.10) Set the eye distance between left eye and right eye (camera 1). This command might be marked as deprecated when we finish multiple camera support.

5. Run UE4 built-in commands

vrun [cmd]

(v0.3) This is a special command used to execute Unreal Engine built-in commands. UE4 provides some built-in commands for development and debug. They are not very well documented, but very useful.

A few examples are:

  • stat FPS - show current frame rate

  • shot - take a screenshot

  • show Material - toggle the display of Material

These commands can be executed in the UE4 console. If you want to use them in UnrealCV, you can prefix these commands with vrun stat FPS.

6. Run Blueprint commands

vbp [obj_name] [func_name] [arg1] [arg2] …

(v0.4.0) This is a special command used to execute Blueprint commands. Blueprint is a visual programming language in UE4. It is widely used in UE4 game development. UnrealCV provides a way to call Blueprint functions from the command line.

A few examples are:
  • vbp BP_Player_C GetActorLocation - Get the location of the player

  • vbp BP_Player_C SetActorLocation 100 200 300 - Set the location of the player

Note that the Blueprint function name is case sensitive, depending on how it is defined in the Blueprint editor.