🎮 Summer Coding Quest
Week 1 · Day 2

Build a 3D World

Turn yesterday's blank grey window into a real 3D scene — a ground to stand on, a sun in the sky, a camera to see through, and a player.

⏱ About 45–60 minutes
🎯 Today's mission Raviv, by the end of today you'll press Play and see a proper 3D world: a green floor, a glowing box standing on it, lit by sunlight, viewed through your own camera. The first time your own 3D world appears on screen is a brilliant feeling — let's get there.

What you'll learn

💡 Before you start Open the My First Game project you made yesterday (double-click your Godot shortcut, then click the project). Everything today builds on it.

Part 1 — A fresh 3D scene

  1. Start a new scene

    Top menu: Scene → New Scene. You'll see options for the type of root node.

  2. Choose "3D Scene"

    Click 3D Scene. A node called Node3D appears, and the middle of the screen switches to a 3D view with a grid floor and coloured arrows. This is your empty world.

  3. Rename it and save

    Double-click Node3D in the Scene panel and rename it World. Press Ctrl + S and save it as world.tscn.
💡 Getting around the 3D view Hold the middle mouse button (the scroll wheel) and move the mouse to orbit the camera. Scroll to zoom. Hold Shift + middle button to slide sideways. Have a quick play — you can't break anything by looking around.

Part 2 — Add the ground

  1. Add a shape node

    Click World, then + Add Child Node. Search for MeshInstance3D and create it. A MeshInstance3D is "a slot for a 3D shape" — right now the slot is empty, so nothing shows yet.

  2. Put a flat shape in the slot

    With the MeshInstance3D selected, look at the Inspector on the right. Find Mesh, click the box next to it that says <empty>, and choose New PlaneMesh. A flat square appears — that's your ground.

  3. Make it bigger

    Click the word PlaneMesh that just appeared in the Inspector to open its settings. Set Size to 20 × 20. Now it's a proper field, not a tile. Rename this node Ground.

Part 3 — Add the sun and a player

  1. Add sunlight

    Select World → + Add Child Node → DirectionalLight3D. This is the sun. To stop it shining straight down flat, select it and in the Inspector set Rotation X to about -45.

  2. Add the player block

    Add another child of World: a MeshInstance3D. Give it a New BoxMesh (same way as the plane). Rename it Player.

  3. Lift the box onto the ground

    The box is half-buried in the floor. With Player selected, set its Position Y to 0.5 in the Inspector. Now it sits neatly on top.
💡 X, Y and Z — the three directions Everything in 3D has a position made of three numbers: X is left/right, Y is up/down, and Z is forward/back. The box was sunk halfway because the floor sits at Y = 0 and the box is 1 tall, so its middle needed to go up by 0.5. You'll think in X/Y/Z constantly from now on.

Part 4 — Add a camera and press Play

  1. Add the camera

    Add one more child of World: a Camera3D. This is the eye your game looks through. Right now it's at the centre looking forward, which isn't a great view.

  2. Pull the camera back and up

    Select Camera3D and in the Inspector set Position to X 0, Y 4, Z 8. Then set Rotation X to about -25 so it tilts down towards the box.

  3. Run it

    Press F5. Godot asks for a main scene the first time for this scene — pick Select Current. Your 3D world opens: a green-grey floor, a box standing on it, lit from the side. 🎉
✅ You did it! That box on a sunlit field is the seed of your whole game. Everything — the trees, monsters, villages — gets added to a world built exactly like this one.

Understand it — the four ingredients

Every 3D scene you'll ever build needs the same four kinds of thing. You just added all four:

1. A world to hold everything — your World (a Node3D). A Node3D is simply "anything that has a position in 3D space". It's the tray everything else sits on.

2. Something to see — your Ground and Player (MeshInstance3D). A mesh is any 3D shape: a box, a sphere, a whole castle. If you can see it, it's a mesh.

3. Light — your DirectionalLight3D. Without light, a 3D world is pitch black, exactly like a real room with the curtains shut. "Directional" light acts like the sun: parallel rays coming from one direction.

4. A camera — your Camera3D. The world might exist, but you only see the slice the camera is pointed at. Move the camera, change what the player sees.

💡 The logic to remember World + Mesh + Light + Camera = a scene you can see. If you ever press Play and get a black screen, run through the list: is there a light? is the camera pointing the right way? Nine times out of ten that's the problem.

Play around — level up 🎮

🟢 Level 1 — Easy Give your player some colour. Select Player → in the Inspector find Material Override → New StandardMaterial3D → click it → set Albedo (that just means "base colour") to your favourite colour. Run it.
🟡 Level 2 — Medium Add a second box somewhere on the field as an obstacle. Give it a different colour and a different Position X and Z so it sits apart from the player. Now your world has scenery.
🔴 Level 3 — Spicy Move the Camera3D to a bird's-eye view: try Position Y 12 and Rotation X -90 (straight down). How does the whole game feel different from above? Lots of strategy games use exactly this camera.
🔬 Experiment: turn off the sun Select the DirectionalLight3D and untick Visible at the top of the Inspector (or just delete it). Run the game — everything goes dark! Put it back. Now you can feel why every scene needs a light.

If something went wrong

"Everything is black when I press Play." You're missing a light, or the light is rotated to point away. Add a DirectionalLight3D to World and set its Rotation X to about -45.

"I press Play and see nothing / a tiny dot." The camera is probably inside the floor or facing the wrong way. Re-check Camera3D Position (0, 4, 8) and Rotation X (-25).

"My box is sunk into the floor." Set the Player's Position Y to 0.5 so its middle sits half a box above the ground.

"I added MeshInstance3D but nothing showed up." The Mesh slot is still empty. Select the node and give it a New PlaneMesh or New BoxMesh in the Inspector.

Tomorrow that box stops standing still — you'll drive it around with the keyboard. 🕹️

Previous← Day 1 — Set up & Hello World