# The asteroid-field tables (`AsteroidGroup_00N`)

**Status: ✅ decoded statically, 2026-08-28.** Every number below is an exact
disc census over all 41 `.pak` archives using the corpus reader.

## Where it sits in the chain

[[stage-definition-table]] and [[stage-mission-tables]] already record that a
stage's `Phase_N` block carries an **`AsteroidDefinition`** field naming a `.tbl`
(`test_s8p1_asteroid.tbl` in the `_Test` template, `""` in most phases), and
[[unit-datasheet-static]] already partitions the `Generic` records and finds
**10 per pack whose only field is `{EnumAsteroidGroup}` — "an asteroid-group
file"**. What neither says is what is *inside* those ten files.

```
Stage_SNN . Phase_N . AsteroidDefinition = "S04_asteroid.tbl"
      └── that object:  Generic . EnumAsteroidGroup = "7"
                        AsteroidGroup_000 … AsteroidGroup_006
                              AsteroidModelName  = mob_n050
                              AsteroidFrameName  = Frame_S04_Asteroid_01
                              EnumAsteroid       = 39
```

## ✅ The table

**10 objects per pack × 6 `GP_MAIN_GAME_<lang>` packs = 60**, holding **384
`AsteroidGroup_*` records** in total. Each object has **4 or 7** groups (12
objects with 4, 48 with 7). Every group record carries exactly **three** fields,
present on all 384 with no partials:

| field | distinct values | what it is |
|---|---:|---|
| `AsteroidModelName` | 28 | the mesh — `mob_n050`…`mob_n056` (24 uses each) and `mob_n040`…`mob_n043` (18 each) |
| `AsteroidFrameName` | 64 | `Frame_S<NN>[_pN]_Asteroid_NN` — the placement frame |
| `EnumAsteroid` | 37 | a **count**, 1 … 588; 6 633 asteroids per pack summed |

`Frame_S<NN>_Asteroid` is the same name [[regn-map-grid]] reports the mission
`Route` tables showing independently — the frame is the join to the map data.

## ✅ `Enum<Thing>` is a count; `Enumerate<Thing>` names a table

`EnumAsteroidGroup` equals the number of `AsteroidGroup_*` records in its own
object in **54 of 60** objects, and `EnumAsteroid` is a plain integer. That is
the opposite of the `Enumerate*` convention, where the value is a child table's
file name. **The `-erate` is the difference**, and it is worth checking the
spelling before assuming which kind a field is.

⚠️ `Count`-style fields still are not safe: the **6 failures are one object,
repeated once per language pack** — it declares `4` and contains `7`.

## 🔑 The tenth object is unreferenced, and it is the one that miscounts

Joining the ten objects to the nine `AsteroidDefinition` values by frame prefix:

| object's frame prefix | groups | declared | named by |
|---|---:|---:|---|
| `Frame_S01_Asteroid` | 4 | 4 | `S01_asteroid.tbl` |
| `Frame_S04/S05/S13/S14_p1/S14_p2/S08_p1/S08_p2_Asteroid` | 7 | 7 | the matching `SNN[_pN]_asteroid.tbl` |
| `Frame_Test_Asteroid` | 4 | 4 | `test_s8p1_asteroid.tbl` |
| **`Frame_Alpha_S01_Asteroid` + `Frame_Alpha_S01_Haze` + `Frame_TAlpha_S01_Asteroid`** | **7** | **4** | **nothing** |

Nine `AsteroidDefinition` names, nine matching objects, and a **tenth that no
phase names** — an `Alpha` Stage-01 variant with its own `Haze` frames and a
`TAlpha` set. It is also the only object whose declared count is wrong, which is
what an abandoned table looks like.

## 🔑 S28 has an asteroid *volume* but no asteroid *definition*

[[mcol-collision]] lists **nine** `_AsteroidVolume_wp` collision meshes: S01,
S04, S05, S08_p1, S08_p2, S13, S14_p1, S14_p2 and **S28_p1**. The nine
`AsteroidDefinition` values are the same eight stages plus **`test_s8p1`**. So
the two sets share eight and differ by one each: **`S28_p1` has the collision
volume for an asteroid field but no table saying which rocks to scatter in it**,
while `test_s8p1` has a table with no volume of its own.

## 🟡 Not settled

* What `EnumAsteroid` counts *of* — instances per frame is the obvious reading
  and the 1…588 range fits, but it is untested.
* Why `S28_p1` has a volume and no definition (S28 is the challenge mission that
  alone flies `rou_f004`, see [[stage-numbering-and-player-craft]]).
* 🔴 **The name→object join did not reproduce by hash.** `AsteroidDefinition`
  values do not map to their objects' pak entry keys under `name_hash`, nor under
  that key reduced `mod 0x00FFF9D7` or masked to 24 bits — the join above is by
  frame prefix, which is direct. Either these keys are not name hashes or
  [[archive-naming]]'s resolver differs from `unitgroup.name_hash`; not chased.