Building Your First Level · Beginner · 14 min
Block Out Your First Level with Simple Shapes
Greybox a whole level out of plain cubes and planes before you touch any art — so you nail the layout, the scale and the feel first, and never waste hours decorating a room that was the wrong size.
Before this: Navigate the UE5 Viewport Like You've Done It for Years, Place, Move, Rotate and Scale Actors in UE5
- Explain what blockout (greyboxing) is and why pros do it before any art
- Place basic shapes (cubes and planes) into a level
- Scale and position shapes against a human-sized reference
- Use grid snapping to keep everything aligned and tidy
Build the rough shape first, decorate later
Before a level has a single texture, tree or fancy mesh, it usually exists as a collection of plain grey boxes. That's not laziness — it's the smartest way to start, and it's how professional studios work. The technique is called blockout (you'll also hear 'greyboxing' or 'whiteboxing'), and it just means roughing out your whole level using basic shapes like cubes and planes.
Why bother? Because layout is the hard part, and art is the slow part. If you spend hours decorating a beautiful room and then discover the doorway is too narrow or the jump is impossible, you have to tear it all down. Blockout lets you test the size, the flow and the fun of a space in minutes, using shapes you can move around freely. Once the grey version feels right, you replace the boxes with real art. In this lesson you'll build a simple room you can walk through — all out of shapes.
The vocabulary of blockout
Tap a card to flip it
The golden rule: build to human scale
Here is the one number that will save you the most pain: in Unreal, 1 unit equals 1 centimetre, and a standing human character is about 180 units tall (1.8 metres). Every wall, doorway and step you block out should be sized against that.
It is incredibly easy to build a room that looks fine in the editor but is secretly enormous or tiny — because from the editor camera there's nothing to compare it to. The fix is simple: keep a human-sized reference in your scene. A default cube placed in Unreal is 100 units on each side, so two cubes stacked is roughly head height. Use that as your mental ruler while you work, and your spaces will feel right the moment you walk them in-game.
Before you start
Tick these off so you've got a clean slate to greybox in:
- A project open with a level you can edit (the Third Person template, or a fresh Basic/Open World level both work fine)
- Comfortable moving the camera around — fly with right-mouse + WASD, frame with F
- Comfortable selecting an actor and using the Move, Rotate and Scale tools (the W, E and R gizmos)
- The Details panel visible on the right (it shows the selected actor's Location, Rotation and Scale)
Block out a simple room
Work top to bottom. Each step stays ticked even if you close the page and come back, so you can greybox at your own pace.
- 1Open the Place Actors panel and find the shapes
Look at the toolbar at the top-left of the editor for the 'Create' (or '+ Add') button, and choose 'Shapes' — or open the Place Actors panel from the Window menu. Either way you get a small palette of basic shapes: Cube, Sphere, Cylinder, Cone and Plane.
These are the building blocks of every blockout. We'll mostly use Cube (for walls and props) and Plane (for the floor).
TipIf you can't find it, use the Window menu at the top and look for 'Place Actors' — it opens the same shape palette as a dockable panel you can keep on screen.
- 2Drag a Plane into the level as your floor
Click and drag the 'Plane' from the palette into the viewport and let go. A flat square drops into the scene — this is your floor.
Select it (left-click), and in the Details panel on the right look at its Scale. Bump the X and Y scale up (try 10 each) to make a floor big enough to walk around on. The plane gets bigger without getting any thicker.
TipA default plane is 100 units across at scale 1. Scaling it to 10 makes it 1000 units (10 metres) wide — a comfortable room footprint for a first try.
- 3Place a Cube and scale it into a wall
Drag a 'Cube' into the level. By default it's 100 units on every side — already about waist-high on a person, which makes it a handy ruler.
With the cube selected, switch to the Scale tool (press R) and stretch it: make it long and tall but thin, so it becomes a wall. You can also type exact numbers into the Details panel's Scale fields — for example X 10, Y 0.2, Z 2.5 gives a long, thin, taller-than-human wall.
TipPrefer typing Scale values in the Details panel over dragging the gizmo when you want precision. Walls especially look much better when their numbers are clean.
- 4Turn on grid snapping and line the walls up
Find the snapping controls in the top-right of the viewport toolbar — there's a grid icon with a number next to it (the snap size, e.g. 10). Make sure grid snap is enabled.
Now duplicate your wall (select it and press Ctrl+W, or Alt+drag the Move gizmo to drag off a copy) and position the copies to form the four sides of a room. With snapping on, each wall jumps in clean steps so the corners actually meet instead of leaving gaps.
TipAlt + drag on the Move gizmo is the fastest way to duplicate: it leaves the original in place and pulls a copy out along the axis you drag.
- 5Add a doorway by leaving a gap
Don't build a solid wall on one side. Instead, make two shorter wall segments with a gap between them — that gap is your doorway. Size the gap to be comfortably wider than a person (a person is ~180 units tall and far less than that wide, so a gap of around 150–200 units feels generous).
This is the whole point of blockout: you're testing whether a player can fit and move through, not what the door looks like.
TipStand a spare cube on its end next to the gap as a stand-in human (remember: roughly 180 units tall). If the doorway dwarfs or crowds it, adjust before moving on.
- 6Walk your room
Press Play (the green play button, or Alt+P). If you're in a template with a character, you'll spawn in and can walk around your greybox room using the movement keys.
Walk up to the walls, through the doorway, around the space. This is the moment of truth — a level always feels different at eye level than from the editor camera. Note anything that feels too big, too cramped, or awkward, then press Escape and fix it.
TipNo character spawns? You may need a Player Start actor in the level. That's covered in the next lesson — for now you can also use the editor's 'Simulate' or just inspect the room from the camera at human height.
Shortcuts that make blockout fast
- W Move tool — drag the arrows to slide an actor along an axis
- E Rotate tool — spin an actor
- R Scale tool — stretch a shape into a wall, floor or pillar
- Alt drag Duplicate: hold Alt and drag the Move gizmo to pull off a copy
- Ctrl W Duplicate the selected actor in place
- F Focus — frame the selected shape so you can work on it up close
- End Snap the selected actor straight down onto the surface below it
You built a room that looked perfectly sized in the editor, but when you pressed Play your character was tiny and the walls towered like a cathedral. What went wrong, and how do you avoid it?
The room had no scale reference, so you sized it by eye from the editor camera — which has no sense of how big a person is. It's an extremely common beginner trap: editor 'looks right' and human 'feels right' are not the same thing.
The fix is to always build against a human-sized reference. Remember 1 unit = 1 cm and a character is about 180 units tall. Keep a stand-in (a cube scaled to roughly human height, or the actual character) in the scene while you block out, and check the space by pressing Play and walking it. Adjust in grey — it's cheap — long before you add any art.
Two ways to make your blockout shapes
Drag Cube, Plane, Cylinder and friends straight from the shapes palette. They're simple, instantly editable with the Move/Rotate/Scale tools, and perfect for a first blockout.
This is the fastest way to learn and the route this lesson uses. You can build an entire playable greybox with nothing but scaled cubes and a plane.
Unreal also ships built-in Modeling Mode tools (switch the editor mode dropdown to 'Modeling'). These let you create shapes and then cut, push and edit their faces — handy for carving an actual door hole into a wall instead of leaving a gap, or for more organic blockouts.
It's more powerful but also more to learn. Most beginners block out with simple shapes first and reach for the modeling tools once the basic workflow feels natural. There's no rush.
Block out a two-room layout: a starting room and a second room, connected by a doorway, with a single step or low ledge the player has to get up. Build it all from scaled cubes and a plane floor, keep grid snapping on, and size everything so it feels right for a ~180-unit character. Then press Play and walk the whole path.
Hint 1
Make the floor first (a scaled-up Plane), then build walls as thin, tall cubes around it.
Hint 2
For the connecting doorway, leave a gap between two wall segments wider than a person.
Hint 3
For the step, scale a cube down low (small Z) and place it as a ledge — keep it low enough to walk or jump onto, not a sheer wall.
Hint 4
Use Alt+drag to duplicate walls so they all match, and keep snapping on so corners meet.
Drag in a Plane and scale it (e.g. 20 x 12) for a long footprint covering both rooms. Drag in a Cube, scale it thin and tall for a wall (e.g. X 10, Y 0.2, Z 2.5), then Alt+drag copies to wall off two rooms. Leave a ~150–200 unit gap in the shared wall for the doorway.
For the step, duplicate a cube and scale it low (e.g. Z 0.3) and place it where the floor changes — low enough to step onto. Keep grid snap enabled so everything aligns. Press Play (Alt+P) and walk from the first room, up the step, through the doorway, into the second room.
If the step felt too tall, the doorway too tight, or a room too vast, that's the lesson working — fix it in grey now, while it costs you seconds instead of hours.
QuizCheck yourself
1Why do level designers block out a level with plain grey shapes before adding any art?
Layout is the hard part and art is the slow part. Blockout lets you get the space right in minutes using shapes you can move freely, before committing to art.
2In Unreal, roughly how tall is a standing human character, and what is 1 unit?
1 unit = 1 cm, and a character is roughly 180 units (1.8 m) tall. That's your scale ruler for every wall, doorway and step.
3What does turning on grid snapping do while you move shapes around?
Snapping moves actors in fixed increments (e.g. 10 units), so walls meet at the corners and your blockout stays tidy and aligned.
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Questions beginners ask
Do I have to use the modeling tools, or are simple cubes enough?
Simple cubes and planes from the shapes palette are completely enough for your first blockouts — you can build an entire playable level with nothing but scaled cubes and a floor plane. The built-in Modeling Mode tools are more powerful (they let you cut actual door holes into walls, for example), but they're a next step. Learn with simple shapes first; reach for modeling once the basic flow feels natural.
How big should a room or doorway be?
Size everything against a human at about 180 units (1.8 m) tall, since 1 unit = 1 cm. A doorway gap of roughly 150–200 units feels comfortable to walk through, and a first room of around 1000 units (10 m) across is a friendly size. The real test is always to press Play and walk it — adjust by feel, not just by numbers.
Why does my room feel huge or tiny when I press Play even though it looked fine in the editor?
The editor camera has no sense of human scale, so spaces routinely 'look right' but 'feel wrong' once you're walking them at eye level. Keep a human-sized reference in your scene (a cube scaled to ~180 units, or the actual character) while you build, and always sanity-check by pressing Play. It's the single most common beginner mistake, and the easiest to fix while everything is still grey.
Should I add lights and textures while I block out?
Not yet. Keep the blockout deliberately grey so you judge the space by its shape and flow rather than its looks. Lighting and materials come once the layout is locked — adding them early just means redoing the work every time you move a wall.