MGLFillExtrusionStyleLayer

 

@interface MGLFillExtrusionStyleLayer : MGLVectorStyleLayer

An MGLFillExtrusionStyleLayer is a style layer that renders one or more 3D extruded polygons on the map.

Use a fill-extrusion style layer to configure the visual appearance of polygon or multipolygon features. These features can come from vector tiles loaded by an MGLVectorTileSource object, or they can be MGLPolygon, MGLPolygonFeature, MGLMultiPolygon, or MGLMultiPolygonFeature instances in an MGLShapeSource or MGLComputedShapeSource object.

You can access an existing fill-extrusion style layer using the -[MGLStyle layerWithIdentifier:] method if you know its identifier; otherwise, find it using the MGLStyle.layers property. You can also create a new fill-extrusion style layer and add it to the style using a method such as -[MGLStyle addLayer:].

See the Display 3D buildings example to learn how to add and style 3D layers on a map.

Example

let layer = MGLFillExtrusionStyleLayer(identifier: "buildings", source: buildings)
layer.sourceLayerIdentifier = "building"
layer.fillExtrusionHeight = NSExpression(forKeyPath: "height")
layer.fillExtrusionBase = NSExpression(forKeyPath: "min_height")
layer.predicate = NSPredicate(format: "extrude == 'true'")
mapView.style?.addLayer(layer)

  • Returns a fill-extrusion style layer initialized with an identifier and source.

    After initializing and configuring the style layer, add it to a map view’s style using the -[MGLStyle addLayer:] or -[MGLStyle insertLayer:belowLayer:] method.

    Declaration

    Objective-C

    - (nonnull instancetype)initWithIdentifier:(nonnull NSString *)identifier
                                    source:(nonnull MGLSource *)source;

    Swift

    init(identifier: String, source: MGLSource)

    Parameters

    identifier

    A string that uniquely identifies the source in the style to which it is added.
    source

    The source from which to obtain the data to style. If the source has not yet been added to the current style, the behavior is undefined.

    Return Value

    An initialized foreground style layer.

    View Source on GitHub

Accessing the Paint Attributes

  • The height with which to extrude the base of this layer. Must be less than or equal to fillExtrusionHeight.

    This property is measured in meters.

    The default value of this property is an expression that evaluates to the float 0. Set this property to nil to reset it to the default value.

    This property is only applied to the style if fillExtrusionHeight is non-nil. Otherwise, it is ignored.

    You can set this property to an expression containing any of the following:

    • Constant numeric values no less than 0
    • Predefined functions, including mathematical and string operators
    • Conditional expressions
    • Variable assignments and references to assigned variables
    • Interpolation and step functions applied to the $zoomLevel variable and/or feature attributes

    Declaration

    Objective-C

    @property (assign, readwrite, nonatomic, null_resettable)
    NSExpression *fillExtrusionBase;

    Swift

    var fillExtrusionBase: NSExpression! { get set }
    View Source on GitHub

  • The transition affecting any changes to this layer’s fillExtrusionBase property.

    This property corresponds to the fill-extrusion-base-transition property in the style JSON file format.

    Declaration

    Objective-C

    @property (assign, readwrite, nonatomic)
    MGLTransition fillExtrusionBaseTransition;

    Swift

    var fillExtrusionBaseTransition: MGLTransition { get set }
    View Source on GitHub

  • The base color of this layer. The extrusion’s surfaces will be shaded differently based on this color in combination with the light settings. If this color is specified with an alpha component, the alpha component will be ignored; use fillExtrusionOpacity to set layer opacityco.

    The default value of this property is an expression that evaluates to UIColor.blackColor. Set this property to nil to reset it to the default value.

    This property is only applied to the style if fillExtrusionPattern is set to nil. Otherwise, it is ignored.

    You can set this property to an expression containing any of the following:

    • Constant UIColor values
    • Predefined functions, including mathematical and string operators
    • Conditional expressions
    • Variable assignments and references to assigned variables
    • Interpolation and step functions applied to the $zoomLevel variable and/or feature attributes

    Declaration

    Objective-C

    @property (assign, readwrite, nonatomic, null_resettable)
    NSExpression *fillExtrusionColor;

    Swift

    var fillExtrusionColor: NSExpression! { get set }
    View Source on GitHub

  • The transition affecting any changes to this layer’s fillExtrusionColor property.

    This property corresponds to the fill-extrusion-color-transition property in the style JSON file format.

    Declaration

    Objective-C

    @property (assign, readwrite, nonatomic)
    MGLTransition fillExtrusionColorTransition;

    Swift

    var fillExtrusionColorTransition: MGLTransition { get set }
    View Source on GitHub

  • Whether to apply a vertical gradient to the sides of a fill-extrusion layer. If true, sides will be shaded slightly darker farther down.

    The default value of this property is an expression that evaluates to YES. Set this property to nil to reset it to the default value.

    This attribute corresponds to the fill-extrusion-vertical-gradient layout property in the Mapbox Style Specification.

    You can set this property to an expression containing any of the following:

    • Constant Boolean values
    • Predefined functions, including mathematical and string operators
    • Conditional expressions
    • Variable assignments and references to assigned variables
    • Step functions applied to the $zoomLevel variable

    This property does not support applying interpolation functions to the $zoomLevel variable or applying interpolation or step functions to feature attributes.

    Declaration

    Objective-C

    @property (assign, readwrite, nonatomic, null_resettable)
    NSExpression *fillExtrusionHasVerticalGradient;

    Swift

    var fillExtrusionHasVerticalGradient: NSExpression! { get set }
    View Source on GitHub

  • The height with which to extrude this layer.

    This property is measured in meters.

    The default value of this property is an expression that evaluates to the float 0. Set this property to nil to reset it to the default value.

    You can set this property to an expression containing any of the following:

    • Constant numeric values no less than 0
    • Predefined functions, including mathematical and string operators
    • Conditional expressions
    • Variable assignments and references to assigned variables
    • Interpolation and step functions applied to the $zoomLevel variable and/or feature attributes

    Declaration

    Objective-C

    @property (assign, readwrite, nonatomic, null_resettable)
    NSExpression *fillExtrusionHeight;

    Swift

    var fillExtrusionHeight: NSExpression! { get set }
    View Source on GitHub

  • The transition affecting any changes to this layer’s fillExtrusionHeight property.

    This property corresponds to the fill-extrusion-height-transition property in the style JSON file format.

    Declaration

    Objective-C

    @property (assign, readwrite, nonatomic)
    MGLTransition fillExtrusionHeightTransition;

    Swift

    var fillExtrusionHeightTransition: MGLTransition { get set }
    View Source on GitHub

  • The opacity of the entire fill extrusion layer. This is rendered on a per-layer, not per-feature, basis, and data-driven styling is not available.

    The default value of this property is an expression that evaluates to the float 1. Set this property to nil to reset it to the default value.

    You can set this property to an expression containing any of the following:

    • Constant numeric values between 0 and 1 inclusive
    • Predefined functions, including mathematical and string operators
    • Conditional expressions
    • Variable assignments and references to assigned variables
    • Interpolation and step functions applied to the $zoomLevel variable

    This property does not support applying interpolation or step functions to feature attributes.

    Declaration

    Objective-C

    @property (assign, readwrite, nonatomic, null_resettable)
    NSExpression *fillExtrusionOpacity;

    Swift

    var fillExtrusionOpacity: NSExpression! { get set }
    View Source on GitHub

  • The transition affecting any changes to this layer’s fillExtrusionOpacity property.

    This property corresponds to the fill-extrusion-opacity-transition property in the style JSON file format.

    Declaration

    Objective-C

    @property (assign, readwrite, nonatomic)
    MGLTransition fillExtrusionOpacityTransition;

    Swift

    var fillExtrusionOpacityTransition: MGLTransition { get set }
    View Source on GitHub

  • Name of image in style images to use for drawing image fill-extrusions. For seamless patterns, image width and height must be a factor of two (2, 4, 8, …, 512).

    You can set this property to an expression containing any of the following:

    • Constant string values
    • Predefined functions, including mathematical and string operators
    • Conditional expressions
    • Variable assignments and references to assigned variables
    • Interpolation and step functions applied to the $zoomLevel variable and/or feature attributes

    Declaration

    Objective-C

    @property (assign, readwrite, nonatomic, null_resettable)
    NSExpression *fillExtrusionPattern;

    Swift

    var fillExtrusionPattern: NSExpression! { get set }
    View Source on GitHub

  • The transition affecting any changes to this layer’s fillExtrusionPattern property.

    This property corresponds to the fill-extrusion-pattern-transition property in the style JSON file format.

    Declaration

    Objective-C

    @property (assign, readwrite, nonatomic)
    MGLTransition fillExtrusionPatternTransition;

    Swift

    var fillExtrusionPatternTransition: MGLTransition { get set }
    View Source on GitHub

  • The geometry’s offset.

    This property is measured in points.

    The default value of this property is an expression that evaluates to an NSValue object containing a CGVector struct set to 0 points rightward and 0 points downward. Set this property to nil to reset it to the default value.

    This attribute corresponds to the fill-extrusion-translate layout property in the Mapbox Style Specification.

    You can set this property to an expression containing any of the following:

    • Constant CGVector values
    • Predefined functions, including mathematical and string operators
    • Conditional expressions
    • Variable assignments and references to assigned variables
    • Interpolation and step functions applied to the $zoomLevel variable

    This property does not support applying interpolation or step functions to feature attributes.

    Declaration

    Objective-C

    @property (assign, readwrite, nonatomic, null_resettable)
    NSExpression *fillExtrusionTranslation;

    Swift

    var fillExtrusionTranslation: NSExpression! { get set }
    View Source on GitHub

  • The transition affecting any changes to this layer’s fillExtrusionTranslation property.

    This property corresponds to the fill-extrusion-translate-transition property in the style JSON file format.

    Declaration

    Objective-C

    @property (assign, readwrite, nonatomic)
    MGLTransition fillExtrusionTranslationTransition;

    Swift

    var fillExtrusionTranslationTransition: MGLTransition { get set }
    View Source on GitHub

  • Controls the frame of reference for fillExtrusionTranslation.

    The default value of this property is an expression that evaluates to map. Set this property to nil to reset it to the default value.

    This property is only applied to the style if fillExtrusionTranslation is non-nil. Otherwise, it is ignored.

    This attribute corresponds to the fill-extrusion-translate-anchor layout property in the Mapbox Style Specification.

    You can set this property to an expression containing any of the following:

    • Constant MGLFillExtrusionTranslationAnchor values
    • Any of the following constant string values:
      • map: The fill extrusion is translated relative to the map.
      • viewport: The fill extrusion is translated relative to the viewport.
    • Predefined functions, including mathematical and string operators
    • Conditional expressions
    • Variable assignments and references to assigned variables
    • Step functions applied to the $zoomLevel variable

    This property does not support applying interpolation functions to the $zoomLevel variable or applying interpolation or step functions to feature attributes.

    Declaration

    Objective-C

    @property (assign, readwrite, nonatomic, null_resettable)
    NSExpression *fillExtrusionTranslationAnchor;

    Swift

    var fillExtrusionTranslationAnchor: NSExpression! { get set }
    View Source on GitHub