gov.nasa.worldwind.globe

Interface Terrain

All Known Implementing Classes:

BasicTerrain

public interface Terrain

Surface of a planet or celestial object. Models the geometric surface defined by an ellipsoidal globe and its associated elevations. A terrain uses the Cartesian coordinate system specified by the globe's GeographicProjection, and therefore may model either an ellipsoid or an arbitrary 2D projection.

Implementations of this interface may model a subset of the globe's surface, and at an arbitrary (or varying) resolution. Unless the terrain implementation is known to represent a pre-determined region of the Globe's surface, method such as intersect and surfacePoint are not guaranteed to compute the desired Cartesian coordinate. Additionally, the results of these methods must be interpreted as representing an arbitrary resolution, unless the terrain implementation is known to represent a pre-determined resolution.

Method Summary

Modifier and Type	Method and Description
Globe	getGlobe() Indicates the globe modeled by this terrain.
Sector	getSector() Indicates the geographic rectangular region that contains this terrain.
double	getVerticalExaggeration() Indicates the geometric surface's vertical exaggeration.
boolean	intersect(Line line, Vec3 result) Computes the first intersection of this terrain with a specified line in Cartesian coordinates.
boolean	surfacePoint(double latitude, double longitude, double offset, Vec3 result) Computes the Cartesian coordinates of a geographic location on the terrain surface.

Method Detail

getGlobe

Globe getGlobe()

Indicates the globe modeled by this terrain.

Returns:

the terrain's globe

getVerticalExaggeration

double getVerticalExaggeration()

Indicates the geometric surface's vertical exaggeration.

Returns:

the terrain's vertical exaggeration

getSector

Sector getSector()

Indicates the geographic rectangular region that contains this terrain. The returned sector may contain geographic areas where the terrain is nonexistent.

Returns:

the terrain's bounding sector

intersect

boolean intersect(Line line,
                  Vec3 result)

Computes the first intersection of this terrain with a specified line in Cartesian coordinates. The line is interpreted as a ray; intersection points behind the line's origin are ignored. If the line does not intersect the geometric surface modeled by this terrain, this returns false and does not modify the result argument.

Parameters:

line - the line to intersect with this terrain

result - a pre-allocated Vec3 in which to return the intersection point

Returns:

true if the ray intersects this terrain, otherwise false

Throws:

java.lang.IllegalArgumentException - if either argument is null

surfacePoint

boolean surfacePoint(double latitude,
                     double longitude,
                     double offset,
                     Vec3 result)

Computes the Cartesian coordinates of a geographic location on the terrain surface. If the latitude and longitude are outside the geometric surface modeled by this terrain, this returns false and does not modify the result argument.

Parameters:

latitude - the location's latitude in degrees

longitude - the location's longitude in degrees

offset - a vertical offset in meters applied to the terrain height

result - a pre-allocated Vec3 in which to store the computed X, Y and Z Cartesian coordinates

Returns:

true if the geographic location is on the terrain surface, otherwise false

Throws:

java.lang.IllegalArgumentException - if the result is null