📐 Lesson 2.2: The Transform — Position, Rotation, Scale

Every GameObject has a Transform. It answers three questions: where is it, which way is it facing, and how big is it? Master these three and you can place anything, anywhere.

🎯 Learning Objectives

Understand the 3D axis system: X, Y, Z
Use Position, Rotation, and Scale to place objects
Use the on-screen Move, Rotate, and Scale tools
Understand parenting and local vs world space (gently)

Estimated Time: 35 minutes

In This Lesson

The 3D Axis System

3D space has three directions, and Unity gives each a colour you'll see everywhere:

X (red) — left ↔ right
Y (green) — down ↕ up
Z (blue) — back ↔ forward

A position like (2, 0.5, -3) means "2 right, 0.5 up, 3 back" from the world centre. Memorize the colours now — they appear on the move tool, the Transform fields, and the scene gizmo.

💡 Memory aid: Red = Right-left (X). Green grows up (Y). Blue goes into the screen (Z).

Position, Rotation, Scale

These three cubes are identical GameObjects — only their Transforms differ. The left cube is normal, the middle is rotated 45° around Y, and the right is scaled to be twice as tall:

A real Unity render of three cubes on a floor: a normal cube, a cube rotated 45 degrees, and a taller stretched cube. — Figure 1: Same object, three Transforms — real render. Rotation turns it; Scale stretches it.

Field	Meaning	Example
Position	Where the object sits, in units	`(0, 0.5, 0)` = half a unit up
Rotation	How it's turned, in degrees	`(0, 45, 0)` = turned 45° around Y
Scale	Its size multiplier (1 = normal)	`(1, 2, 1)` = twice as tall

The Transform Tools

You can type exact values in the Inspector or drag with the on-screen tools. The tool buttons live at the top-left of the Toolbar, and each has a keyboard shortcut:

Move (W) — drag the coloured arrows to reposition.
Rotate (E) — drag the coloured rings to turn.
Scale (R) — drag the coloured handles to resize.

✅ Pro Tip

Drag for rough placement, then fine-tune with exact numbers in the Inspector. For anything that needs to be precise (like sitting exactly on the floor), always type the value.

Parenting: Transforms Inside Transforms

In the Hierarchy you can drag one GameObject onto another to make it a child. A child moves, rotates, and scales with its parent — like a hat on a head.

graph TD P[Car ] --> W1[Wheel FL] P --> W2[Wheel FR] P --> W3[Wheel RL] P --> W4[Wheel RR]

Move the Car and all four wheels follow. A child's Transform values are measured relative to its parent — that's called local space. This is why the robot in our example scene has dozens of child bones that all move with it.

💡 Don't overthink this yet. Just remember: children follow their parent. We'll use parenting practically when we build the mini-game.

Hands-on Exercise

🏋️ Exercise: Recreate Figure 1

In a scene with a floor, add three Cubes.
Cube 1: Position (-2.5, 0.5, 0), leave rotation and scale default.
Cube 2: Position (0, 0.5, 0), Rotation (0, 45, 0).
Cube 3: Scale (1, 2, 1), then Position (2.5, 1, 0) so it rests on the floor.

💡 Why Position Y = 1 for the tall cube?

Scaling to height 2 makes it 2 units tall, so its centre must be 1 unit up to sit on the floor (half of 2).

🎯 Quick Quiz

Question 1: Which axis points up?

Question 2: A child GameObject's position moves when...

Summary

🎉 Key Takeaways

3D uses three colour-coded axes: X right/left, Y up/down, Z forward/back.
The Transform holds Position, Rotation, and Scale.
Use the Move (W), Rotate (E), Scale (R) tools or type exact values.
Children follow their parent's Transform.

🚀 What's Next?

Objects have shape and position — next we make them look good. Lesson 2.3 covers meshes and materials (colour!).