---
title: "WindArrowLayerOptions | Weather SDK | JavaScript maps SDK"
description: "Documentation for Weather JS"
---

# Type Alias WindArrowLayerOptions

type WindArrowLayerOptions \= {  
    [color](#color)?: [RgbaColor](https://docs.maptiler.com/sdk-js/modules/weather/api-reference/types/RgbaColor/);  
    [colorramp](#colorramp)?: [ColorRamp](https://docs.maptiler.com/sdk-js/modules/weather/api-reference/classes/ColorRamp/);  
    [density](#density)?: number;  
    [fastColor](#fastcolor)?: [RgbaColor](https://docs.maptiler.com/sdk-js/modules/weather/api-reference/types/RgbaColor/);  
    [fastSpeedNorm](#fastspeednorm)?: number;  
    [id](#id)?: string;  
    [maxAmount](#maxamount)?: number;  
    [opacity](#opacity)?: number;  
    [refreshInterval](#refreshinterval)?: number;  
    [rttTimestep](#rtttimestep)?: number;  
    [size](#size)?: number;  
    [smooth](#smooth)?: boolean;  
    [speed](#speed)?: number;  
}

##### Index

### Properties

[color?](#color) [colorramp?](#colorramp) [density?](#density) [fastColor?](#fastcolor) [fastSpeedNorm?](#fastspeednorm) [id?](#id) [maxAmount?](#maxamount) [opacity?](#opacity) [refreshInterval?](#refreshinterval) [rttTimestep?](#rtttimestep) [size?](#size) [smooth?](#smooth) [speed?](#speed)

## Properties

### `Optional`color[](#color)

color?: [RgbaColor](https://docs.maptiler.com/sdk-js/modules/weather/api-reference/types/RgbaColor/)

Color of the arrows when slow. RGBA 0-255. Defaults: `[255, 255, 255, 192]`

### `Optional`colorramp[](#colorramp)

colorramp?: [ColorRamp](https://docs.maptiler.com/sdk-js/modules/weather/api-reference/classes/ColorRamp/)

Coloramp to use. Default: VIRIDIS scale from `0` to `40` (speed in m/s)

### `Optional`density[](#density)

density?: number

Number of arrows visible per 1000 px^2. Default: `2`.

### `Optional`fastColor[](#fastcolor)

fastColor?: [RgbaColor](https://docs.maptiler.com/sdk-js/modules/weather/api-reference/types/RgbaColor/)

Color of the arrows when fast. RGBA 0-255. Defaults: `[255, 255, 255, 192]`

### `Optional`fastSpeedNorm[](#fastspeednorm)

fastSpeedNorm?: number

Normalised wind speed threshold (0–1 relative to the data's max wind speed) at which the arrow color fully transitions from `color` to `fastColor`. 0.5 = blend completes at half of the maximum encoded wind speed. Default: `0.5`

### `Optional`id[](#id)

id?: string

ID of the layer

### `Optional`maxAmount[](#maxamount)

maxAmount?: number

Quantity of arrows to be created. Has to be a power of 2 and at least `4`. The actual exact number will be `arrows * arrows`. Try to keep this value as low as possible to optimize performance.

The number of actually visible arrows is determined by `options.density`.

Default:`128`.

### `Optional`opacity[](#opacity)

opacity?: number

Opacity of the background in the range \[0, 1\]. Default: `0.8`.

Note: does not affect the opacity of the arrows, this is defined as part of the arrow color (alpha component)

### `Optional`refreshInterval[](#refreshinterval)

refreshInterval?: number

Time interval (in milliseconds) how often the arrows are refreshed to avoid degradation. Random `1/4` of the arrows is always randomly reset. Default value is `800`.

### `Optional`rttTimestep[](#rtttimestep)

rttTimestep?: number

Max ms between particle simulation steps. Lower = smoother motion; `0` = every frame. Default: `1000/60` (~60Hz).

### `Optional`size[](#size)

size?: number

Size of the arrows. Default: `18`

### `Optional`smooth[](#smooth)

smooth?: boolean

Whether or not the colorramp must be smooth

### `Optional`speed[](#speed)

speed?: number

Speed factor of the arrows. Defaults: `0.001`