VoxelLayer

• Overview
• Creating a VoxelLayer
• Data Visualization
• Exploring a Voxel Layer
• VoxelLayer Volume
• VoxelLayer and time

Overview

A voxel layer represents multidimensional volumetric data. For example, atmospheric or oceanic data, geological underground models, or space-time cubes can be visualized as voxel layer. The VoxelLayer can be visualized in a SceneView with the viewingMode set to local.

Use voxel layers to explore spatial relationships with other content. For example, an underground model visualized as a voxel layer can be viewed together with buildings or subterrain utilities to evaluate the underground for planned construction or maintenance.

Creating a VoxelLayer

From ArcGIS Pro, you can author a voxel layer and publish it as a Scene Service. Scene Services can be hosted on ArcGIS Online or ArcGIS Enterprise by uploading a Scene Layer Package (.slpk) or by sharing it from ArcGIS Pro.

The Scene Service is identified by a service URL or portal item ID and can be used to create an instance of a VoxelLayer.

const voxelLayer = new VoxelLayer({
   url: "https://tiles.arcgis.com/tiles/z2tnIkrLQ2BRzr6P/arcgis/rest/services/EMU_Caribbean_Voxel/SceneServer"
});
const map = new Map({
   layers: [voxelLayer],
   basemap: {
     baseLayers: [
       new VectorTileLayer({
         url: "https://basemaps.arcgis.com/arcgis/rest/services/OpenStreetMap_GCS_v2/VectorTileServer"
       })
     ]
   }
});

const voxelLayer = new VoxelLayer({
   portalItem: {
     id: "3a922ed0c7a8489ea4fbe8747ac560ba"
   },
});

Data Visualization

Voxel layers can be visualized as volumes or surfaces using the property renderMode. When set to surfaces, only isosurfaces and sections are displayed, whereas volume draws the full volume.

A voxel layer contains variables representing continuous or discrete data. For example, permeability could be defined as a continuous variable and soil type as a discrete variable. Voxel layer only visualizes one variable at a time. A VoxelVariable describes a single variable in the VoxelLayer. The currentVariableId controls which variable is being rendered.

You can define how a continuous or discrete variable can be rendered. You can apply a data filter to, modify the color scheme of, or add transparency to a continuous variable by using VoxelTransferFunctionStyle. For a discrete variable, you can modify the color and label by using uniqueValues.

Exploring a Voxel Layer

Voxel layers often cover large areas. There are various capabilities you can use to explore the voxel layer in detail.

VoxelSlice

Use VoxelSlice to define an area of interest. You can slice a voxel layer vertically to show a smaller volume, or horizontally slice to reduce the voxel layer to a specific height.

It is possible to have multiple slices in a VoxelLayer by modifying the VoxelVolumeStyle's slices or by authoring slices in ArcGIS Pro before publishing the voxel layer as a scene service.

Slices modified using VoxelVolumeStyle's slices and the slices authored from ArcGIS Pro are persistent in the web scene or layer definition respectively.

Position, tilt and orientation of a VoxelSlice can be modified with real-time rendering updates.

VoxelDynamicSection

A section is a plane which cuts through a voxel volume. Sections can reveal valuable information, such as soil composition and contamination across a subsurface profile. The VoxelDynamicSection allows you to define the properties of an individual dynamic section. You can create VoxelDynamicSection to understand structures in the voxel layer. For example, you can create a cross section diagram to explore an underground model at locations where new construction is planned. VoxelDynamicSection can only be visualized when the renderMode is set to surfaces.

Position, tilt and orientation of a VoxelDynamicSection can be modified with real-time rendering updates.

VoxelIsosurface

A VoxelIsosurface is a surface representing a specific value within a continuous variable. For example, you can visualize a threshold value for pollutants in the atmosphere as an isosurface. This allows you to identify the location of key values. You can visualize isosurfaces together with sections. VoxelIsosurface can only be visualized when the renderMode is set to surfaces.

By default, the color of an isosurface matches the color in the colorStops for the specific value. You can choose a different color and lock the color by using the property colorLocked in VoxelIsosurface. You can have up to four isosurfaces in a voxel layer.

Analysis Tool

The Slice, DirectLineMeasurement3D and AreaMeasurement3D works with VoxelLayer.

Slice

The VoxelLayer treats the slice as an infinite plane and ignores the slice plane extent.

Slice widget allows you to interactively modify a single slice. The visualization created using the Slice widget are temporary and cannot be persisted in a WebScene or in slides.

Measurement

The DirectLineMeasurement3D and AreaMeasurement3D allows you to select points in the VoxelLayer to measure. However, the selection of the points and the measurement results may not be accurate. The measurement results include the verticalExaggeration applied to the VoxelLayer.

Popup

You can explore the properties of individual voxels by enabling popups. Take note that popups are not configurable in VoxelLayer and use a default template. The popup will show different attributes depending on the voxel’s volume. All datasets will have the attributes Variable, Value and Voxel Position. If the dataset includes Z coordinate it will have the attribute Depth and if it includes time it will have the attributes Local and Native time.

VoxelLayer Volume

The voxel layer is structured in dimensional regularly gridded cubes that store one or many variables.

A voxel layer can represent different dimensions. The volumeType property in VoxelVolume defines the dimension of the voxel layer.

• X, Y, Z in which each dimension represents a geographic coordinate

• X, Y, T in which X and Y represent a geographic coordinate and T represents time as a level

• X, Y, Z, T in which each dimension represents geographic coordinates and includes a fourth dimension representing time.

VoxelLayer and time

A VoxelLayer enables the visualization of time as the fourth dimension if the volumeType is "xyzt". A volumeType of "xyt" is not a time-aware layer. The time is represented along the z dimension.

You can access the temporal data of a VoxelLayer by using the stops in the TimeInfo. The stops indicates time instants that a layer has data for. You can use the stops with the TimeSlider widget or use it to configure the VoxelLayer's timeExtent.

The layer and the view can have a different TimeExtent. The useViewTime determines if the VoxelLayer will show the data based on the view's timeExtent or the layer's timeExtent.