column-layer.md

import {ColumnLayerDemo} from 'website-components/doc-demos/layers';

ColumnLayer

This is the primitive layer rendered by HexagonLayer after aggregation. Unlike the HexagonLayer, it renders one column for each data object.

The ColumnLayer can be used to render a heatmap of vertical cylinders. It renders a tessellated regular polygon centered at each given position (a "disk"), and extrude it in 3d.

import DeckGL from '@deck.gl/react';
import {ColumnLayer} from '@deck.gl/layers';

function App({data, viewState}) {
  /**
   * Data format:
   * [
   *   {centroid: [-122.4, 37.7], value: 0.2},
   *   ...
   * ]
   */
  const layer = new ColumnLayer({
    id: 'column-layer',
    data,
    diskResolution: 12,
    radius: 250,
    extruded: true,
    pickable: true,
    elevationScale: 5000,
    getPosition: d => d.centroid,
    getFillColor: d => [48, 128, d.value * 255, 255],
    getLineColor: [0, 0, 0],
    getElevation: d => d.value
  });

  return <DeckGL viewState={viewState}
    layers={[layer]}
    getTooltip={({object}) => object && `height: ${object.value * 5000}m`} />;
}

Installation

To install the dependencies from NPM:

npm install deck.gl
# or
npm install @deck.gl/core @deck.gl/layers

import {ColumnLayer} from '@deck.gl/layers';
new ColumnLayer({});

To use pre-bundled scripts:

<script src="https://unpkg.com/deck.gl@^8.0.0/dist.min.js"></script>
<!-- or -->
<script src="https://unpkg.com/@deck.gl/core@^8.0.0/dist.min.js"></script>
<script src="https://unpkg.com/@deck.gl/layers@^8.0.0/dist.min.js"></script>

new deck.ColumnLayer({});

Properties

Inherits from all Base Layer properties.

Render Options

diskResolution (Number, optional)

• Default: 20

The number of sides to render the disk as. The disk is a regular polygon that fits inside the given radius. A higher resolution will yield a smoother look close-up, but also need more resources to render.

radius (Number, optional)

• Default: 1000

Disk size in units specified by radiusUnits (default meters).

angle (Number, optional)

• Default: 0

Disk rotation, counter-clockwise in degrees.

vertices (Array, optional)

Replace the default geometry (regular polygon that fits inside the unit circle) with a custom one. The length of the array must be at least diskResolution. Each vertex is a point [x, y] that is the offset from the instance position, relative to the radius.

offset ([Number, Number], optional)

• Default: [0, 0]

Disk offset from the position, relative to the radius. By default, the disk is centered at each position.

coverage (Number, optional)

• Default: 1

Radius multiplier, between 0 - 1. The radius of the disk is calculated by coverage * radius

elevationScale (Number, optional)

• Default: 1

Column elevation multiplier. The elevation of column is calculated by elevationScale * getElevation(d). elevationScale is a handy property to scale all column elevations without updating the data.

filled (Boolean, optional)

• Default: true

Whether to draw a filled column (solid fill).

stroked (Boolean, optional)

• Default: false

Whether to draw an outline around the disks. Only applies if extruded: false.

extruded (Boolean, optional)

• Default: true

Whether to extrude the columns. If set to false, all columns will be rendered as flat polygons.

wireframe (Boolean, optional)

• Default: false

Whether to generate a line wireframe of the column. The outline will have "horizontal" lines closing the top and bottom polygons and a vertical line (a "strut") for each vertex around the disk. Only applies if extruded: true.

radiusUnits (String, optional)

• Default: 'meters'

The units of the radius, one of 'meters', 'common', and 'pixels'. See unit system.

lineWidthUnits (String, optional)

• Default: 'meters'

The units of the line width, one of 'meters', 'common', and 'pixels'. See unit system.

lineWidthScale (Boolean, optional)

• Default: 1

The line width multiplier that multiplied to all outlines if the stroked attribute is true.

lineWidthMinPixels (Number, optional)

• Default: 0

The minimum outline width in pixels.

lineWidthMaxPixels (Number, optional)

• Default: Number.MAX_SAFE_INTEGER

The maximum outline width in pixels.

material (Object, optional)

• Default: true

This is an object that contains material props for lighting effect applied on extruded polygons. Check the lighting guide for configurable settings.

Data Accessors

getPosition (Function, optional)

• Default: object => object.position

Method called to retrieve the position of each column, in [x, y]. An optional third component can be used to set the elevation of the bottom.

getFillColor (Function|Array, optional)

• Default: [0, 0, 0, 255]

The rgba color is in the format of [r, g, b, [a]]. Each channel is a number between 0-255 and a is 255 if not supplied.

• If an array is provided, it is used as the color for all objects.
• If a function is provided, it is called on each object to retrieve its color.
• If not provided, it falls back to getColor.

getLineColor (Function|Array, optional)

• Default: [0, 0, 0, 255]

The rgba color is in the format of [r, g, b, [a]]. Each channel is a number between 0-255 and a is 255 if not supplied.

• If an array is provided, it is used as the outline color for all columns.
• If a function is provided, it is called on each object to retrieve its outline color.
• If not provided, it falls back to getColor.

getElevation (Function|Number, optional)

• Default: 1000

The elevation of each cell in meters.

• If a number is provided, it is used as the elevation for all objects.
• If a function is provided, it is called on each object to retrieve its elevation.

getLineWidth (Function|Number, optional)

• Default: 1

The width of the outline of the column, in units specified by lineWidthUnits (default meters). Only applies if extruded: false and stroked: true.

• If a number is provided, it is used as the outline width for all columns.
• If a function is provided, it is called on each object to retrieve its outline width.

Source

modules/layers/src/column-layer