Layers

DeckGL.jl provides a variety of layer types for different visualization needs. This page documents all available layers and their properties.

Core Layers

Core layers render individual data points directly without aggregation.

ScatterplotLayer

Renders circles at given coordinates.

ScatterplotLayer(
    data = data,
    get_position = [:lng, :lat],
    get_radius = 100,
    get_fill_color = [255, 140, 0, 200]
)

Property	Type	Default	Description
data	Any	required	Tables.jl-compatible data source
get_position	Symbol/Vector{Symbol}	required	Position accessor [:lng, :lat]
get_radius	Real/Symbol	1	Circle radius in meters
get_fill_color	Vector/Symbol	[0,0,0,255]	Fill color RGBA
get_line_color	Vector/Symbol	[0,0,0,255]	Outline color RGBA
get_line_width	Real/Symbol	1	Outline width
radius_scale	Real	1	Radius multiplier
radius_min_pixels	Real	0	Minimum radius in pixels
radius_max_pixels	Real	Inf	Maximum radius in pixels
stroked	Bool	false	Draw outline
filled	Bool	true	Draw fill
billboard	Bool	false	Always face camera
opacity	Real	1	Layer opacity (0-1)
pickable	Bool	false	Enable interactions

ArcLayer

Renders arcs between source and target coordinates.

ArcLayer(
    data = trips,
    get_source_position = [:src_lng, :src_lat],
    get_target_position = [:dst_lng, :dst_lat],
    get_source_color = [0, 128, 255],
    get_target_color = [255, 0, 128],
    get_width = 2
)

Property	Type	Default	Description
data	Any	required	Tables.jl-compatible data source
get_source_position	Symbol/Vector{Symbol}	required	Source position
get_target_position	Symbol/Vector{Symbol}	required	Target position
get_source_color	Vector/Symbol	[0,0,0,255]	Source end color
get_target_color	Vector/Symbol	[0,0,0,255]	Target end color
get_width	Real/Symbol	1	Arc width in pixels
get_height	Real/Symbol	1	Arc height multiplier (0-1)
get_tilt	Real/Symbol	0	Arc tilt in degrees
great_circle	Bool	false	Use great circle arcs
width_scale	Real	1	Width multiplier
opacity	Real	1	Layer opacity (0-1)

LineLayer

Renders straight lines between source and target coordinates.

LineLayer(
    data = connections,
    get_source_position = [:from_lng, :from_lat],
    get_target_position = [:to_lng, :to_lat],
    get_color = [255, 0, 0],
    get_width = 2
)

Property	Type	Default	Description
data	Any	required	Tables.jl-compatible data source
get_source_position	Symbol/Vector{Symbol}	required	Source position
get_target_position	Symbol/Vector{Symbol}	required	Target position
get_color	Vector/Symbol	[0,0,0,255]	Line color
get_width	Real/Symbol	1	Line width
width_units	String	"pixels"	Width units
opacity	Real	1	Layer opacity (0-1)

PathLayer

Renders paths/polylines from coordinate sequences.

PathLayer(
    data = routes,
    get_path = :path,  # Column containing [[lng1,lat1], [lng2,lat2], ...]
    get_color = [0, 128, 255],
    get_width = 5,
    cap_rounded = true
)

Property	Type	Default	Description
data	Any	required	Tables.jl-compatible data source
get_path	Symbol	required	Path coordinates column
get_color	Vector/Symbol	[0,0,0,255]	Path color
get_width	Real/Symbol	1	Path width
cap_rounded	Bool	false	Round line caps
joint_rounded	Bool	false	Round line joints
billboard	Bool	false	Always face camera
miter_limit	Real	4	Miter limit for sharp corners
opacity	Real	1	Layer opacity (0-1)

PolygonLayer

Renders filled and/or stroked polygons.

PolygonLayer(
    data = regions,
    get_polygon = :polygon,
    get_fill_color = [255, 140, 0, 100],
    get_line_color = [255, 140, 0, 255],
    extruded = true,
    get_elevation = :value
)

Property	Type	Default	Description
data	Any	required	Tables.jl-compatible data source
get_polygon	Symbol	required	Polygon coordinates column
get_fill_color	Vector/Symbol	[0,0,0,255]	Fill color
get_line_color	Vector/Symbol	[0,0,0,255]	Outline color
get_line_width	Real/Symbol	1	Outline width
filled	Bool	true	Draw fill
stroked	Bool	true	Draw outline
extruded	Bool	false	Extrude as 3D
wireframe	Bool	false	Draw 3D wireframe
get_elevation	Real/Symbol	1000	Polygon height for 3D
elevation_scale	Real	1	Elevation multiplier
opacity	Real	1	Layer opacity (0-1)

TextLayer

Renders text labels at coordinates.

TextLayer(
    data = cities,
    get_position = [:lng, :lat],
    get_text = :name,
    get_size = 16,
    get_color = [0, 0, 0]
)

Property	Type	Default	Description
data	Any	required	Tables.jl-compatible data source
get_position	Symbol/Vector{Symbol}	required	Position accessor
get_text	Symbol	required	Text content column
get_size	Real/Symbol	32	Text size in pixels
get_color	Vector/Symbol	[0,0,0,255]	Text color
get_angle	Real/Symbol	0	Rotation in degrees
get_text_anchor	String	"middle"	Horizontal anchor
get_alignment_baseline	String	"center"	Vertical anchor
font_family	String	"Monaco, monospace"	Font family
billboard	Bool	true	Always face camera
background	Bool	false	Draw background
opacity	Real	1	Layer opacity (0-1)

Aggregation Layers

Aggregation layers bin data points and render aggregated values.

HexagonLayer

Aggregates data into hexagonal bins and renders as 3D hexagons.

HexagonLayer(
    data = earthquakes,
    get_position = [:lng, :lat],
    get_elevation_weight = :magnitude,
    radius = 50000,
    elevation_scale = 100,
    extruded = true
)

Property	Type	Default	Description
data	Any	required	Tables.jl-compatible data source
get_position	Symbol/Vector{Symbol}	required	Position accessor
radius	Real	1000	Hexagon radius in meters
coverage	Real	1	Hexagon coverage (0-1)
extruded	Bool	true	Render as 3D
elevation_scale	Real	1	Elevation multiplier
elevation_range	Vector	[0, 1000]	Min/max elevation
get_color_weight	Real/Symbol	1	Color aggregation weight
get_elevation_weight	Real/Symbol	1	Elevation aggregation weight
color_aggregation	String	"SUM"	Aggregation method
elevation_aggregation	String	"SUM"	Aggregation method
color_range	Vector	yellow-red scale	Color gradient
upper_percentile	Real	100	Upper filter percentile
lower_percentile	Real	0	Lower filter percentile
opacity	Real	1	Layer opacity (0-1)

GridLayer

Aggregates data into rectangular grid cells.

GridLayer(
    data = points,
    get_position = [:lng, :lat],
    cell_size = 200,
    elevation_scale = 4,
    extruded = true
)

Property	Type	Default	Description
data	Any	required	Tables.jl-compatible data source
get_position	Symbol/Vector{Symbol}	required	Position accessor
cell_size	Real	1000	Grid cell size in meters
coverage	Real	1	Cell coverage (0-1)
extruded	Bool	true	Render as 3D
elevation_scale	Real	1	Elevation multiplier
get_color_weight	Real/Symbol	1	Color aggregation weight
get_elevation_weight	Real/Symbol	1	Elevation aggregation weight
color_aggregation	String	"SUM"	Aggregation method
elevation_aggregation	String	"SUM"	Aggregation method
opacity	Real	1	Layer opacity (0-1)

HeatmapLayer

Renders a heatmap based on point density and weights.

HeatmapLayer(
    data = incidents,
    get_position = [:lng, :lat],
    get_weight = :severity,
    radius_pixels = 50,
    intensity = 1,
    threshold = 0.03
)

Property	Type	Default	Description
data	Any	required	Tables.jl-compatible data source
get_position	Symbol/Vector{Symbol}	required	Position accessor
radius_pixels	Real	30	Radius of influence in pixels
intensity	Real	1	Intensity multiplier
threshold	Real	0.05	Minimum density threshold
get_weight	Real/Symbol	1	Point weight
color_range	Vector	blue-green-yellow-red	Color gradient
aggregation	String	"SUM"	Aggregation method
opacity	Real	1	Layer opacity (0-1)

Composite Layers

Composite layers render complex data types using multiple sub-layers.

GeoJsonLayer

Renders GeoJSON data as points, lines, and polygons.

# From Dict
geojson_data = Dict(
    "type" => "FeatureCollection",
    "features" => [...]
)

GeoJsonLayer(
    data = geojson_data,
    get_fill_color = [255, 0, 0, 100],
    get_line_color = [255, 0, 0, 255],
    get_point_radius = 100
)

# From URL
GeoJsonLayer(
    data = "https://example.com/data.geojson",
    filled = true,
    stroked = true
)

Property	Type	Default	Description
data	Dict/String	required	GeoJSON Dict or URL
filled	Bool	true	Fill polygons
stroked	Bool	true	Draw outlines
extruded	Bool	false	Extrude polygons
get_fill_color	Vector/Symbol	[0,0,0,255]	Fill color
get_line_color	Vector/Symbol	[0,0,0,255]	Line color
get_line_width	Real/Symbol	1	Line width
get_point_radius	Real/Symbol	1	Point radius
get_elevation	Real/Symbol	1000	Polygon elevation
point_type	String	"circle"	Point rendering type
opacity	Real	1	Layer opacity (0-1)

GeoInterface.jl Integration

Convert GeoInterface-compatible geometries to GeoJSON:

using Shapefile
using DeckGL

# Load shapefile
shp = Shapefile.Table("boundaries.shp")

# Convert to GeoJSON and create layer
layer = geojson_layer(shp, get_fill_color=[255, 0, 0, 100])

# Or manually convert
geojson_dict = to_geojson(shp)
layer = GeoJsonLayer(data=geojson_dict)

Supported geometry types:

• Point, MultiPoint
• LineString, MultiLineString
• Polygon, MultiPolygon
• GeometryCollection
• Feature, FeatureCollection