## 2. What option 11 shows

- **The bot is built from an icosahedron,** a 20-faced solid. Each step on the slider splits every face into 4: 20 → 80 → 320 → 1,280 faces.
- **Flat facets vs smooth:**
  - Flat lights each face as one colour, so you see every fold.
  - Smooth blends light across the corners.
  - At 80 faces, smooth shading already fakes a round ball. Only the outline still gives away the facets.
- **Most of the world has no textures.** Trees, rocks and mountains are coloured per corner (vertex colours). That kept the tiny texture memory free for the grass.
- **The grass texture is only 16×16 pixels.** Switch filters to see what hardware did with so little:

| Filter | Look |
|---|---|
| Nearest | Crisp, blocky squares (PS1 style) |
| 3-point (N64) | Soft, with faint diagonal seams, blending 3 texels instead of 4 |
| Bilinear | Smooth blur, the modern default |

## 3. Less obvious details

- **3-point filtering is a real N64 quirk.** It split each texel square into two triangles and blended 3 corners, saving hardware. Look closely at the grass checker edges: the blur has a diagonal bias.
- **Texture memory was 4 KB.** A 32×32 texture in full colour nearly filled it. That's why N64 games were famously blurry and leaned on vertex colours.
- **"Video blur" imitates the output stage.** The console softened each line horizontally before sending it to the TV. It smoothed jaggies and looked like a smudge.
- **The eyes are decals.** Flat black shapes sit just above the facets, re-fitted to whatever facet they cross. At 20 faces you can see them bend over the sharp ridges.
- **Fog was everywhere on the N64.** It hid the short draw distance. Untick it and the mountain ring pops out as hard, flat cut-outs.
- **The waddle and somersault** borrow 3D platformer body language: side-to-side roll while hopping, plus a full flip on a higher arc.

## Examples

**Icosphere subdivision**
```
level 0: 20 faces        level 1: each face → 4
    ▲                        ▲
   ╱ ╲                      ╱▼╲
  ╱   ╲         →          ╱▲─▲╲
 ▔▔▔▔▔▔▔                  ▔▔▔▔▔▔▔
new corners pushed out to the sphere → rounder each step
```

**3-point vs bilinear**
```
bilinear: blend all 4        3-point: pick a triangle, blend 3
 A ─── B                      A ─── B
 │  ●  │  weights A,B,C,D     │ ● ╱ │  if fx+fy<1: A,B,C
 C ─── D                      C ╱── D  else:        D,B,C
```

**N64 vs PS1 at a glance**
```
                 PS1                 N64
depth buffer     no (sorting)        yes
textures         affine, sharp       perspective-correct, filtered
texture memory   ~1 MB VRAM          4 KB TMEM
common look      wobbly, crisp       stable, soft, foggy
```