Wireframe 2019

wfmag.cc \ 33

Creating a jetpack in Unreal Engine 4

Toolbox

WORKING WITH BLUEPRINTS
We’re going to build on the first-person
blueprint to create our Jetpack mechanic. First,
a quick tour of the interface: along the taskbar
are the standard options for saving and loading
maps, preferences we can set for the project,
and windows for specific tools in the editor. The
window to the top-left, called Modes, contains
various editing modes and objects that are
available within those modes. Currently, we have
Place mode selected,
which allows us to
place game objects into
our scene.
To the right of this
is our viewport; it also
has some large icons above it that have a few
different uses, including the option to preview
our game inside the viewport. To the right
of that is the World Outliner, and this is the
hierarchy of the objects we currently have in the
scene. Any details on a selected object appear
below in the details panel. Finally, the window on
the bottom left-hand side is the content browser
and shows all the content that is imported
and usable in our project, such as materials,
animations, and meshes.
Sticking with the content browser, we first
need to access the Content folder. If you can’t
see the folder, then select the icon to the
left-hand side of the word Filters. Expand the
Content folder by clicking the right arrow and
then navigating to FirstPersonBP > Blueprints,
and then double-click the icon named
FirstPersonCharacter, which is our blueprint
object. To make working on the blueprint easier,
select the window and drag it up to the main
window next to the FirstPersonExampleMap
tab. This makes the entire blueprint full screen
instead of a smaller, free-floating window.

Now we have the blueprint open, we should

be able to see the Event Graph: this is where

we can do most of the setup for our blueprint.

We’re going to look for the code that relates to

the character’s jump

input. This should be

commented in the

blueprint, so move

around the viewport

and look for the word

Jump. We essentially want to remove the jump

and replace it with our Jetpack mechanic. So,

we need to delete the two function nodes,

which are the blue nodes named Jump and

Stop Jumping.

We will create our own boolean, or true and

false value, to evaluate whether we’re using

the jetpack or not. To add the new variable,

move over to the left-hand side of the blueprint

interface. Look for the panel called My Blueprint

• this should have an entry called Variables. Click
  the + button to add a new variable. Now look at
  the Details panel on the right-hand side of the

“By moving to UE4,

we can look at another

way of scripting logic”

 All together now:

“Fly, my pretty... Fly!”

 Each frame, we need to know the current

frame rate, and if we have our key for the

jetpack activated. The following layout in

the Event Graph will achieve this.

EVENT

GRAPHS

You can navigate the Event

Graph by holding the right

mouse button to drag around

the viewport and using the

scroll wheel to zoom in and

out. You can also select

multiple nodes by dragging

across them with the left

mouse button. To add our

own comments, you can

select multiple nodes and

then press the C key on

the keyboard. Feel free to

comment the elements of the

Jetpack code as you follow

the tutorial.