Computing plausible road surfaces in 3D from 2D geometry

摘要

Road network data can include two dimensional (2D) coordinates corresponding to junctions and non-junctions in the road network. Height values for roads at junctions can be obtained from optimizing a cost function or as input. Height values for roads at non-junction locations can be obtained from a height function defined using the height values for the junctions. Pitch, yaw, and roll vectors can be obtained for non-junction locations using the height function, the 2D coordinates, and one or more road parameters, respectively. These vectors can define a coordinate frame for the road, along with which a width can provide points for defining polygons for the road. Road surface data can be constructed from the polygons. The polygons can be provided to a device display for rendering of a three dimensional image of navigation data.

主权项

1. A method for generating polygons of a road surface for a road network area that includes a plurality of junctions, the method comprising:
receiving a junction data set for each junction in the road network area, wherein each junction data set includes a first coordinate and a second coordinate; receiving a non-junction data set for each non-junction location in the road network area, wherein each non-junction location includes a first coordinate and a second coordinate, the non-junction data set defining locations of road segments between junctions; determining, by a computing device, height values of the road segments at each junction; for each of a plurality of road segments:
computing, by the computing device, a height function defining a change in height of the road segment between the corresponding two junctions;for each non-junction location of the road segment:
calculating a yaw vector using a two dimensional vector between the non-junction location and a successive location, wherein a road element connects the non-junction location and the successive location;determining a pitch using a change in the height function at the non-junction location; anddetermining a roll based on one or more road parameters;for each road element of the road segment:
constructing, by the computing device, a set of polygons based on:
a road width at the two locations which the road element is between,the pitch at each of the two locations,the yaw vector at each of the two locations, andthe roll at each of the two locations; and transmitting, from the computing device to a display device, data based on the set of polygons for displaying, by the display device, a three-dimensional map of a part of the road network area.