roadrunner.hdmap.MultiPolygon

R2026b

Define multiple polygon geometries for RoadRunner HD Map objects using MATLAB

Since R2022b

Description

The roadrunner.hdmap.MultiPolygon object defines a collection of polygon geometries for RoadRunner HD Map objects. It groups one or more roadrunner.hdmap.Polygon objects to represent complex regions. The polygons in a MultiPolygon object must not overlap each other. However, you can place polygons inside the holes of other polygons. You can use a MultiPolygon object to assign geometry to map features such as junctions, represented by roadrunner.hdmap.Junction objects. For an example of how to create a complete T-junction with roads, maneuver lanes, and traffic signal phases that include bulb-level signal control, see Build Signalized Junction Using RoadRunner HD Map.

Creation

Syntax

multiPoly = roadrunner.hdmap.MultiPolygon

multiPoly = roadrunner.hdmap.MultiPolygon(PropertyName=Value)

Description

multiPoly = roadrunner.hdmap.MultiPolygon creates an empty MultiPolygon object.

multiPoly = roadrunner.hdmap.MultiPolygon(PropertyName=Value) specifies one or more properties of the MultiPolygon object using name-value arguments.

Properties

Polygons — Collection of polygon geometries

roadrunner.hdmap.Polygon.empty (default) | array of roadrunner.hdmap.Polygon objects

Collection of polygon geometries, specified as an array of roadrunner.hdmap.Polygon objects. This property specifies the polygon geometries that define the MultiPolygon region

Examples

Define MultiPolygon Geometry for a RoadRunner HD Map

Create multiple polygon geometries and combine them into a MultiPolygon object to represent a complex region in a RoadRunner HD Map.

Define a closed outer ring for the first polygon.

outer1 = [0 0; 10 0; 10 10; 0 10; 0 0];

Create a roadrunner.hdmap.Polygon object using the outer ring. Leave the InteriorRings property empty so the polygon represents a solid region.

polyNoHole = roadrunner.hdmap.Polygon(ExteriorRing=outer1) % Polygon without a hole

polyNoHole = 
  Polygon with properties:

     ExteriorRing: [5×2 double]
    InteriorRings: {}

Define a closed outer ring and an inner ring for the second polygon.

outer2 = [15 0; 25 0; 25 10; 15 10; 15 0];
inner = [18 3; 22 3; 22 7; 18 7; 18 3];

Create a roadrunner.hdmap.Polygon object with a hole by specifying the inner ring to the InteriorRings property.

polyWithHole = roadrunner.hdmap.Polygon(ExteriorRing=outer2,InteriorRings={inner}) % Polygon with a hole

polyWithHole = 
  Polygon with properties:

     ExteriorRing: [5×2 double]
    InteriorRings: {[5×2 double]}

Combine the Polygon objects into a roadrunner.hdmap.MultiPolygon object.

multiPoly = roadrunner.hdmap.MultiPolygon(Polygons=[polyNoHole polyWithHole])

multiPoly = 
  MultiPolygon with properties:

    Polygons: [2×1 roadrunner.hdmap.Polygon]

Convert each Polygon into a polyshape object to enable you to visualize the MultiPolygon in MATLAB™. Use NaN values to separate the outer and inner rings of polygons that contain holes. Then, plot the polygons side by side.

figure
hold on

% Loop through each Polygon in the MultiPolygon
for i = 1:length(multiPoly.Polygons)
    poly = multiPoly.Polygons(i);
    outer = poly.ExteriorRing;

    % Check if the polygon has no holes
    if isempty(poly.InteriorRings)
        p = polyshape(outer(:,1),outer(:,2),'Simplify',true);
    else
        % Initialize coordinates with outer boundary
        x_outer = outer(:,1);
        y_outer = outer(:,2);

        % Loop through each inner boundary
        for j = 1:length(poly.InteriorRings)
            inner = poly.InteriorRings{j};
            x_inner = [x_outer; NaN; inner(:,1)];
            y_inner = [y_outer; NaN; inner(:,2)];
        end
        p = polyshape(x_inner,y_inner,'Simplify',true);
    end

    % Plot the polygon
    plot(p,FaceAlpha=0.3)
end

axis equal
grid on
title("MultiPolygon Visualization")
xlabel("X(m)")
ylabel("Y(m)")

Version History

Introduced in R2022b