Shadow Cast

ESM:

Use dark colors for code blocksCopy
import "@arcgis/map-components/components/arcgis-shadow-cast";

CDN:

No specific import is needed for this component.

Since:ArcGIS Maps SDK for JavaScript 4.28

The Shadow Cast component displays the cumulative shadows of 3D features in a Scene. This type of analysis is helpful in urban development, where new projects have to satisfy certain shadow duration constraints.

The component calculates the cumulative shadows for a time range during a single day. The user can configure the time range and select a calendar date. This time range and calendar date are only used for the shadow analysis and are not connected to the lighting in the scene. To control the lighting in the scene, the Daylight component can be used. Changing the timezone in the component updates the visualization by interpreting the time range as being in that timezone. This behavior is different from the Daylight component, where selecting a timezone updates the environment lighting's date and time according to the camera position.

The component provides three visualization modes: threshold, duration, and discrete mode.

In the threshold mode, only the areas that receive shadows for more than a certain amount of time are displayed. In the image below, on May 1, 2021 the red areas receive shadow for more than 4 hours within the time interval of 10AM to 4PM.

Total shadow duration mode displays the duration of the cumulative shadow using opacity: areas that don't receive any shadow are fully transparent and areas that receive a maximum amount of shadow have a default opacity of 0.7. The values in between are interpolated. Hovering over the Scene will display a tooltip showing the amount of time that location is in shadow, rounded to 15-minute intervals. In this mode, the visualization can display shadow cast in a continuous way or in 1-hour intervals.

Discrete shadows is a third visualization mode which displays individual shadows at a given time interval. For example, setting the time range to 10AM-11AM and the visualization time interval to 30 minutes will display shadows for 10AM, 10:30AM and 11:00AM.

The defaults for the time range and visualization settings can be changed using the startTimeOfDay, endTimeOfDay, and visualizationType properties.

Known limitations

Shadow Cast is only supported in a 3D Scene component.
Terrain does not cast shadows and it is therefore not taken into account in this analysis. This influences the results when the start time of the range is before sunrise or when the end time is after the sunset.
The component does not take into account the daylight savings. Use the timezone dropdown to adjust the offset from the Coordinated Universal Time (UTC) and account for the daylight saving time.
The timezone is automatically detected by the component based on the camera location. In some situations, this might not be accurate. In case of an inaccurate timezone, users can set it manually using the timezone dropdown.

See also

Sample - Shadow cast component

Demo

Properties

Property	Attribute	Type
`autoDestroyDisabled`	`auto-destroy-disabled`	`boolean`
`date`	`date`	`Date \| number \| string`
`discreteOptions`		`DiscreteOptions`
`durationOptions`		`DurationOptions`
`endTimeOfDay`	`end-time-of-day`	`number`
`headingLevel`	`heading-level`	`number`
`hideColorPicker`	`hide-color-picker`	`boolean`
`hideDatePicker`	`hide-date-picker`	`boolean`
`hideThresholdContext`	`hide-threshold-context`	`boolean`
`hideThresholdContextColor`	`hide-threshold-context-color`	`boolean`
`hideThresholdContextTimeInterval`	`hide-threshold-context-time-interval`	`boolean`
`hideThresholdContextToggle`	`hide-threshold-context-toggle`	`boolean`
`hideTimeRangeSlider`	`hide-time-range-slider`	`boolean`
`hideTimezone`	`hide-timezone`	`boolean`
`hideTooltip`	`hide-tooltip`	`boolean`
`hideVisualizationOptions`	`hide-visualization-options`	`boolean`
`icon`	`icon`	`string`
`label`	`label`	`string`
`position` deprecated	`position`	`"bottom-leading" \| "bottom-left" \| "bottom-right" \| "bottom-trailing" \| "manual" \| "top-leading" \| "top-left" \| "top-right" \| "top-trailing"`
`referenceElement`	`reference-element`	`HTMLArcgisLinkChartElement \| HTMLArcgisMapElement \| HTMLArcgisSceneElement \| string`
`startTimeOfDay`	`start-time-of-day`	`number`
`state` readonlyreflected	`state`	`"disabled" \| "ready"`
`thresholdOptions`		`ThresholdOptions`
`utcOffset`	`utc-offset`	`number`
`view`		`SceneView`
`visualizationType`	`visualization-type`	`"discrete" \| "duration" \| "threshold"`

autoDestroyDisabled

Property

autoDestroyDisabled: boolean

If true, the component will not be destroyed automatically when it is disconnected from the document. This is useful when you want to move the component to a different place on the page, or temporarily hide it. If this is set, make sure to call the destroy method when you are done to prevent memory leaks.

Attribute: auto-destroy-disabled
Default value: false

date

Property

date: Date | number | string

The calendar date used to calculate the shadow cast. This date excludes the time. If a date with a time is set, the time value will be set to midnight (00:00:00) of that date in local system time. If no date is set, then it defaults to the current date in local system time.

See also

Date

Attribute: date

discreteOptions

Property

discreteOptions: DiscreteOptions

The configuration used when the component's visualizationType is set to "discrete".

durationOptions

Property

durationOptions: DurationOptions

The configuration used when the component's visualizationType is set to "duration".

endTimeOfDay

Property

endTimeOfDay: number

Time (in milliseconds from midnight of the date) when the shadow cast computation should stop.

Attribute: end-time-of-day
Default value: 16 * 3600 * 1000

headingLevel

Property

headingLevel: number

Indicates the heading level to use for the titles "Time range" and "Visualization".

Attribute: heading-level
Default value: 4

hideColorPicker

Property

hideColorPicker: boolean

Attribute: hide-color-picker
Default value: false

hideDatePicker

Property

hideDatePicker: boolean

Attribute: hide-date-picker
Default value: false

hideThresholdContext

Property

hideThresholdContext: boolean

Attribute: hide-threshold-context
Default value: false

hideThresholdContextColor

Property

hideThresholdContextColor: boolean

Attribute: hide-threshold-context-color
Default value: false

hideThresholdContextTimeInterval

Property

hideThresholdContextTimeInterval: boolean

Attribute: hide-threshold-context-time-interval
Default value: false

hideThresholdContextToggle

Property

hideThresholdContextToggle: boolean

Attribute: hide-threshold-context-toggle
Default value: false

hideTimeRangeSlider

Property

hideTimeRangeSlider: boolean

Attribute: hide-time-range-slider
Default value: false

hideTimezone

Property

hideTimezone: boolean

Attribute: hide-timezone
Default value: false

hideTooltip

Property

hideTooltip: boolean

Attribute: hide-tooltip
Default value: false

hideVisualizationOptions

Property

hideVisualizationOptions: boolean

Attribute: hide-visualization-options
Default value: false

icon

Property

icon: string

Icon which represents the component. Typically used when the component is controlled by another component (e.g. by the Expand component).

See also

Calcite Icons

Attribute: icon
Default value: "measure-building-height-shadow"

label

Property

label: string

The component's default label.

Attribute: label

position

deprecatedProperty

position: "bottom-leading" | "bottom-left" | "bottom-right" | "bottom-trailing" | "manual" | "top-leading" | "top-left" | "top-right" | "top-trailing"

Deprecatedsince 4.34, use slot instead.

Attribute: position

referenceElement

Property

referenceElement: HTMLArcgisLinkChartElement | HTMLArcgisMapElement | HTMLArcgisSceneElement | string

By assigning the id attribute of the Map or Scene component to this property, you can position a child component anywhere in the DOM while still maintaining a connection to the Map or Scene.

See also

Associate components with a Map or Scene component

Attribute: reference-element

startTimeOfDay

Property

startTimeOfDay: number

Time (in milliseconds from midnight of the date) when the shadow cast computation should start.

Attribute: start-time-of-day
Default value: 10 * 3600 * 1000

state

readonly

Property

state: "disabled" | "ready"

The component's state. The values mean the following:

disabled - component is being created
ready - component is ready

Attribute: state
Default value: "disabled"

thresholdOptions

Property

thresholdOptions: ThresholdOptions

The configuration used when the component's visualizationType is set to "threshold".

utcOffset

Property

utcOffset: number

The difference in hours between UTC time and the times displayed in the component.

Attribute: utc-offset

view

Property

view: SceneView

The view associated with the component.

Note: The recommended approach is to fully migrate applications to use map and scene components and avoid using MapView and SceneView directly. However, if you are migrating a large application from widgets to components, you might prefer a more gradual transition. To support this use case, the SDK includes this view property which connects a component to a MapView or SceneView. Ultimately, once migration is complete, the Shadow Cast component will be associated with a map or scene component rather than using the view property.

visualizationType

Property

visualizationType: "discrete" | "duration" | "threshold"

Type of visualization to use when showing the shadows. There are 3 types of visualization:

threshold - only displays areas that receive shadows for a period longer than a given threshold value
duration - displays all areas that receive shadows either in a continuous mode or in 1 hour time intervals
discrete - displays individual shadows cast at a given time interval

Attribute: visualization-type
Default value: "threshold"

Methods

Method	Signature
`componentOnReady`	`componentOnReady(): Promise<void>`
`destroy`	`destroy(): Promise<void>`
`getDuration`	`getDuration(point: __esri.Point): Promise<number>`
`start`	`start(): Promise<void>`
`stop`	`stop(): Promise<void>`

componentOnReady

Method

componentOnReady(): Promise<void>

Create a promise that resolves once component is fully loaded.

Example

Use dark colors for code blocksCopy
const arcgisShadowCast = document.querySelector("arcgis-shadow-cast");
document.body.append(arcgisShadowCast);
await arcgisShadowCast.componentOnReady();
console.log("arcgis-shadow-cast is ready to go!");

Returns: Promise<void>

destroy

Method

destroy(): Promise<void>

Permanently destroy the component.

Returns: Promise<void>

getDuration

Method

getDuration(point: __esri.Point): Promise<number>

Returns the time (in milliseconds) spent in shadow for a certain point on the screen.

Parameter	Type	Optional?
point	`Point`

Returns: Promise<number>

start

Method

start(): Promise<void>

Starts the component. While running, it will automatically perform shadow accumulation.

Returns: Promise<void>

stop

Method

stop(): Promise<void>

Stops the component.

Returns: Promise<void>

Events

Event	Type
`arcgisPropertyChange`	`CustomEvent<{ name: "state"; }>`
`arcgisReady`	`CustomEvent<void>`

arcgisPropertyChange

Event

arcgisPropertyChange: CustomEvent<{ name: "state"; }>

Emitted when the value of a property is changed. Use this to listen to changes to properties.

arcgisReady

Event

arcgisReady: CustomEvent<void>

Emitted when the component associated with a map or scene view is ready to be interacted with.

Shadow Cast

Demo

Properties

Methods

Example

Parameters

Events