Ambient snakes · Torreta-wiki

Now and then a snake slips out of a crevice at the foot of one cliff, crosses the pit floor between the towers and the rubble along its own route, and goes into the rock on the far side; or it crosses the plain above the cliffs, from beyond the frame to beyond it, round the factory, barrack and radar. By day it is a Schokari sand racer, weaving fast; at dusk and at night a Saharan horned viper, sidewinding. Neither comes out in rain or a sandstorm. Rarely a hunter comes for one: by default a buzzard by day or an owl by night stoops on it, takes it in its talons and carries it off. Both leave tracks in the sand: the racer a winding groove, the viper the slanted parallel bars of a sidewinder.

They are scenery only. They have no collision, never touch the combat RNG and are never saved, so a mod that only changes snakes keeps the vanilla profile (achievements, XP and leaderboards stay on).

A mod changes snakes with two optional files beside mod.json:

my_snakes/
  mod.json
  snakes.json           species, timing, limits and hunts
  models.json           Snakes/<Name> GLBs (new species or replacements)
  Models/Cobra.glb

The shipped values are in vanilla_reference/snakes.json (a copy of the game's Data/snakes.json). The stock models are built by tools/art/build_blender_snakes.py; their editable source is Assets/Models/Source/Snakes.blend.

snakes.json

{
  "version": 1,
  "settings": { "capture_chance": 0.3, "hunters": ["buzzard", "owl", "raven"] },
  "species": {
    "horned_viper": { "size": [1.6, 1.8] },
    "sand_racer": { "active": {} },
    "desert_cobra": {
      "model": "Snakes/Cobra", "active": {"twilight": 2},
      "gait": "serpentine", "speed": [20, 28], "size": [1, 1.2],
      "wave_amplitude": 0.07, "wavelength": 0.55
    }
  }
}

The file is merged over the vanilla one key by key: settings field by field, species by id. An empty active silences a species; a new id adds one and needs a model, and inherits the sand racer's other fields. Unknown or invalid fields are named in the mod errors and left out.

settings

Field	Meaning
`enabled`	`false` turns the snakes off.
`density`	Multiplies how often a snake comes out, 0-5.
`first_arrival_seconds`	`[min, max]` before the first one of a run.
`interval_seconds`	`[min, max]` between arrivals, divided by `density`.
`max_snakes`	At most this many at once, per preset (Low, Medium, High, Ultra), up to 8.
`shadows`	Whether they cast shadows, per preset.
`hidden_by_rain`, `hidden_by_sand`	Above this much rain or sand, none come out.
`plateau_share`	The share of crossings on the plain above the cliffs rather than the pit floor, 0-1.
`light_bands`	`day`/`twilight`/`night` as `[min, max]` of the hour's light, like the birds.
`capture_chance`	The chance a snake is hunted, 0-1.
`hunt_delay_seconds`	`[min, max]` after it is clear of its crevice before the hunter is sent.
`hunters`	Bird species ids that hunt snakes; one flying at that hour is sent.

species

Field	Meaning
`model`	A `Snakes/<Name>` model key.
`active`	Bands it comes out in, as a list or `{band: weight}`.
`gait`	`serpentine` (the body follows the head's trail) or `sidewinding`.
`speed`	`[min, max]` in world units per second.
`size`	`[min, max]` scale of the model.
`wave_amplitude`	Sideways swing, as a fraction of the body length (0-0.4).
`wavelength`	Length of one wave, as a fraction of the body length (0.1-2).
`wave_hz`	`[min, max]` waves per second; only sidewinding uses it.
`sidewind_degrees`	How slanted a sidewinder's body lies to its travel.
`lift`	How far a sidewinder lifts the stretches between its contacts.
`sheen`, `scale_lines`	How glossy the scales are, and how strongly their rows show.
`scale_texture`	`"smooth"` or `"keeled"`: a stock scale relief patch drawn over the model (`""`: the procedural lattice).
`scale_rows`, `scale_density`	Scale rows round the body, and along it per unit of the first UV set's U.
`relief`	How deep the scale relief is, 0-2.
`tracks`	How visible its tracks in the sand are, 0-1 (0: none).

Models

A snake model is one straight mesh, in its in-game size: the snout at x = 0, the body along -X (the tail tip at x = -length), the belly on the ground at y = 0 in Godot's frame (+Y up). The game bends it around a spine every frame on the GPU, so it needs no bones. Give it a second UV set (UV2) with U from 0 at the tail tip to 1 at the snout, the spine coordinate, and V as the part code (0 body, 1 head, 2 eye, 3 horn): the eyes get a wet gloss. Without a second UV set the game builds one from the model's length, all body.

Colour comes from the vertex colours (COLOR_0, linear); the scale rows come from the first UV set (U along the body in scale rows, V around it). The stock snakes also read a colour pattern texture beside their GLB (Snakes/<Name>_pattern.png, U the spine coordinate, V round the body from the belly); a mod model keeps its vertex colours, and may still borrow a stock scale relief with scale_texture.