Layer Types

A cloud layer's type decides where it has cloud: the layer reads one weather value at every spot of the sky, and its forms-at and full-at turn that reading into cloud. Type names are not case-sensitive. A layer without a type, or with one that does not exist, is skipped with a console line.

Types

• A layer with the default thickness: -1 only draws where the simulation holds cloud, whatever its type. For fog, dust or high cloud of its own, make it a band, see Layer Options.
• simulated and humidity read 0 outside the simulated sky, so a band of these types above it, such as one on top-clearance, draws nothing. Use outflow, noise or none there.
• noise is a fixed pattern that drifts with the wind, and coverage sets how much of the sky it fills. Leave its forms-at and full-at at the defaults. A shape on it gets half strength and the console warns, so use none for shapes.
• none draws only inside the patches of a shape, so it ignores the weather. Set patches.share, which defaults to 0.

type: humidity
forms-at: 0.7
full-at: 1.0
opacity: 0.3
visible-from-inside: false
voxel-height: 8
thickness: 16
min-y: 160

A see-through band at y160 that shows where the air at that height is damp.

From reading to cloud

The layer turns the reading into a strength: (reading - forms-at) / (full-at - forms-at), kept between 0 and 1.

• Without a shape, nothing is drawn up to a strength of 0.1. Above that the cloud is thin and patchy, and coverage with noise-scale, noise-scale-y and noise-seed decides how much shows. From 0.5 it turns solid, and at 1 only its edges are carved.
• With a shape, the strength sets the share of the form that is drawn: cover at 1, proportionally less below, nothing at 0 outside the patches.
• Where precipitation is above weather.rain-precip-threshold, a thickness: -1 layer is filled in from its base wherever the strength is above 0.1.
• The defaults, 0 and 0.5, suit simulated. surface-humidity, humidity, surface-wind and outflow need a pair in their own unit: with the defaults, a surface-humidity layer draws from 5 percent humidity and is full at 50 percent.
• A full-at above 12.75 for simulated or 25.5 for surface-wind is never reached.

Storm outflow

Storm outflow is thin high cloud that spreads downwind from storms and the tallest clouds.

• Clouds feed it where their tops rise above physics.tropopause-height, or above the bottom of the top 4 levels (4 x grid.cell-size.y blocks) of the simulated sky where that is lower: y256 on a default overworld with the shipped settings, y250 in the shipped winter.
• The wind at clouds.outflow.wind-y carries it. About 37 percent is left after clouds.outflow.minutes weather minutes. With minutes: 0 there is no outflow and outflow layers show only their patches.
• It is not saved, so after a restart outflow layers show only their patches until storms feed it again.

See Cloud Options for the two clouds.outflow settings.

Types from other plugins

• Other plugins can add types, but cannot replace the seven built-in names.
• Until the plugin registers the type, a listed layer of that type is skipped with cloud layer '<name>' has type '<type>', which is not a known cloud layer type; skipping it. The layer appears once the type is registered, without a reload.
• A type that fails draws nothing and logs cloud layer '<name>' (type <type>) failed and draws nothing: <error>, once until the next load.
• For developers: Cloud Layer Types.

Checking the readings

/ms atmosphere stats shows the readings of the weather cell you stand in, before any sample-size averaging:

• Air: the ground humidity in percent (100 percent is a reading of 1.0) and the ground wind in m/s.
• By height: each level's humidity from the top down, and its cloud water in g/kg (cloud) from 0.05. It lists levels with cloud, rain or at least 50 percent humidity, plus your own, marked with >.
• Outflow: the outflow where you stand and the share of the sky above 0.15, while there is any.