Minecraft coding classes

The first mistake

Writing (0, 5, 0) looks like "five blocks up". In a world position it means five blocks above the world origin, which can be far from the player.

Working it out

From (100, 64, -20) to (0, 5, 0) is 100 blocks in x, 59 in y and 20 in z. Squaring, adding and taking the square root gives about 117.8 blocks in a straight line.

The fix

Use a relative position when something should follow the player, and a world position when it must stay put, such as the exact spot of a finish line.

The second, sneakier mistake

Relative positions move with the player. MakeCode warns that they "move" because they start from the player's feet. If a program builds a tower one block at a time while the child walks away, each new block lands next to the player's new position, and the tower comes out crooked.

The fix is to read the player's position once at the start, keep it in a variable, and build every block from that saved spot. That is the moment a child understands why variables exist.

What children learn from it

That the same three numbers can mean completely different places depending on what they are measured from. Programmers call this a frame of reference, and it appears everywhere, from maps to screens to robots.

Older children meet a third kind, the player position, set by the direction the player faces. MakeCode creates it with posCamera, so "three blocks in front of me" works whichever way the player turns.