Workshop › Wolfenstein-style 3D Maze › Step 12 of 18

No fish-eye

What we are doing

Look at a flat wall straight ahead: it bulges, taller in the middle. The side rays are longer, because they go slanted. A real eye (or camera) measures distance straight ahead, so we multiply by the cosine of the ray's angle from the middle.

```js
// The distance straight ahead, not along the ray: otherwise flat walls bulge (the fish-eye effect).
const dist = hit.dist * Math.cos(angle - player.angle)
```

What it means

• angle - player.angle is how far the ray turns from the middle of the view.
• Multiplying the slanted length by its cosine gives the straight-ahead part of it.

Your turn

Replace the dist line with the corrected one, and write the comment above it.

Skills: Velocity and gravity

← The 3D view Light and shade →

All steps

1. The map
2. The player
3. Ceiling, floor and a loop
4. Turn around
5. Walk
6. Is it a wall?
7. Stop at walls, slide along them
8. A ray: where it starts
9. A ray: the grid lines
10. A ray: walk to the wall
11. The 3D view
12. No fish-eye
13. Light and shade
14. A timer
15. Escape!
16. Best time
17. Touch controls
18. Build it yourself: run