class Geometry in Tinman.Terrain.Geometries

Base class for default IGeometry implementations in the Tinman SDK.

abstract class

Geometry

extends

GeometryBase

Public / Attributes

Handedness

Returns the handedness of this geometry object.

[ThreadSafe]
public override property	Handedness { get }
type	CartesianHandedness
value		The coordinate system handedness.
implements	GeometryBase.Handedness

Remarks:

The handedness of a geometry is taken into account when vertex normal vectors are computed: Normal vectors are computed from vertex positions using a counter-clockwise winding in heightmap space. Since heightmap space is always right-handed, all computed normal vectors must be flipped when the application uses a left-handed world coordinate system.

Map

Returns a MapInfo value that describes the used map raster.

public property	Map { get }
type	MapInfo
value		The map info value.
inherited	GeometryBase.Map

ToGeocentric

Returns an instance of Geocentric that corresponds to this geometry.

public virtual property	ToGeocentric { get }
type	Geocentric
value		The Geocentric object or null if this is a custom geometry object.
inherited	GeometryBase.ToGeocentric

Unit

The terrain-space unit.

public virtual property	Unit { get }
type	UnitOfMeasure
value	[not-null]	The terrain-space unit.
inherited	GeometryBase.Unit

Remarks:

The default unit is Metre.

Public / Constructors

ForCoordinateSystem

Creates a new instance of IGeometry that computes geocentric coordinates based on the given georeference.

public static method	ForCoordinateSystem (CoordinateSystem coordSys, MapInfo map, IRasterTransform raster = null)
type	IGeometry
params	coordSys	[not-null]	The coordinate system.
	map		The map raster.
	raster		Optional raster transform. If null, the geometry will be of type Cube; otherwise it will be Rect. Defaults to null.
returns		[not-null]	The created IGeometry object.

Remarks:

Please refer to Cubemap, LatLon and Geocentric for details on the mapping between terrain-space, heightmap, geographic and geocentric coordinates.

For local coordinate systems (see IsLocal ), this method will delegate to Plane.

ForRaster

Creates a new instance of IGeometry that computes geocentric coordinates based on the given georeference.

public static method	ForRaster (Raster raster, MapInfo map)
type	IGeometry
params	raster	[not-null]	The georeference.
	map		The map raster.
returns		[not-null]	The created IGeometry object.

Remarks:

Please refer to Cubemap, LatLon and Geocentric for details on the mapping between terrain-space, heightmap, geographic and geocentric coordinates.

For local coordinate systems (see IsLocal ), this method will delegate to Plane.

Plane

Creates a new instance of IGeometry of type Rect that uses a plane as base geometry.

public static method	Plane (int32 width, int32 height, float64 scale, UnitOfMeasure unit = null)
type	IGeometry
params	width	[>0]	The heightmap width.
	height	[>0]	The heightmap height.
	scale		Scale factor from heightmap coordinates to terrain-space.
	unit		The terrain-space unit. If null, Metre will be used. Defaults to null.
returns		[not-null]	The created IGeometry object.

Remarks:

The positive heightmap space X-axis is mapped to the positive terrain space X-axis, the positive heightmap space Y-axis is mapped to the positive terrain space Z-axis and the heightmap elevation is mapped to the positive terrain space Y-axis. The center sample of the heightmap is mapped to the terrain space origin:

Heightmap space:
----------------

O--------+     +----> X
|(0,0)   |     |
|        |     |
|        |     V
|   (w,h)|
+--------O     Y

Terrain space:
--------------
                  | Z-
 (-w/2,-h/2)      |      (w/2,-h/2)
            +-----+-----+
            |     |     |
            |     |     |
     X- ----+-----0-----+---- X+
            |     |     |
            |     |     |
            +-----+-----+
 (-w/2,-h/2)      |      (w/2,h/2)
                  | Z+

w := Heightmap width, minus one
h := Heightmap height, minus one

Sphere

Creates a new instance of IGeometry that uses a sphere as base geometry.

public static method	Sphere (int32 cubeSize, float64 radius, UnitOfMeasure unit = null)
type	IGeometry
params	cubeSize	[pow2+1]	The heightmap which will be used with the geometry object.
	radius	[>0]	Radius of zero-altitude sphere, in terrain-space.
	unit		The terrain-space unit. If null, Metre will be used. Defaults to null.
returns		[not-null]	The created IGeometry object.

Remarks:

Please refer to Cubemap, LatLon and Geocentric for details on the mapping between terrain-space, heightmap, geographic and geocentric coordinates.

Public / Methods

ComputeCoordinates

Computes the heightmap coordinates that correspond to the given geographic coordinates.

[ThreadSafe]
public virtual method	ComputeCoordinates (LatLon geographic)
type	Vec3D
params	geographic		The geographic coordinates.
returns			The heightmap coordinates or Undefined is this geometry object is not geo-referenced (see ToGeocentric).
inherited	GeometryBase.ComputeCoordinates

---

Computes the heightmap coordinates and elevation that correspond to the given position.

[ThreadSafe]
public abstract method	ComputeCoordinates (float64 positionX, float64 positionY, float64 positionZ, out Vec3D heightmap)
type	float64
params	positionX		X-coordinate of position in terrain-space.
	positionY		Y-coordinate of position in terrain-space.
	positionZ		Z-coordinate of position in terrain-space.
	heightmap		Output for heightmap coordinates.
returns			The terrain-space elevation, in terrain-space units (see Unit).
inherited	GeometryBase.ComputeCoordinates

ComputeLatLon

Computes the geographic coordinates that correspond to the given heightmap coordinates.

[ThreadSafe]
public virtual method	ComputeLatLon (float64 heightmapX, float64 heightmapY, float64 heightmapZ)
type	LatLon
params	heightmapX		The heightmap X-coordinate.
	heightmapY		The heightmap Y-coordinate.
	heightmapZ		The heightmap Z-coordinate.
returns			The geographic coordinates or Undefined if this geometry object is not geo-referenced (see ToGeocentric).
inherited	GeometryBase.ComputeLatLon

ComputeNorth

Computes the vertex north-vector for the given heightmap coordinates.

[ThreadSafe]
public abstract method	ComputeNorth (float64 heightmapX, float64 heightmapY, float64 heightmapZ)
type	Vec3D
params	heightmapX		The heightmap X-coordinate.
	heightmapY		The heightmap Y-coordinate.
	heightmapZ		The heightmap Z-coordinate.
returns			The unit-length vertex north-vector.
inherited	GeometryBase.ComputeNorth

Remarks:

The north-vector is perpendicular to the up-vector and points towards the terrain North Pole, which is defined by the implementing class and can assume different meanings.

ComputePosition

Computes the vertex position that corresponds to the given heightmap coordinates and elevation.

[ThreadSafe]
public abstract method	ComputePosition (float64 heightmapX, float64 heightmapY, float64 heightmapZ, float64 elevation, out Vec3D position, out Vec3D up)
params	heightmapX		The heightmap X-coordinate.
	heightmapY		The heightmap Y-coordinate.
	heightmapZ		The heightmap Z-coordinate.
	elevation		The terrain-space elevation, in terrain-space units (see Unit).
	position		Output for vertex position.
	up		Output for unit-length up-vector.
returns			The vertex position.
inherited	GeometryBase.ComputePosition

ComputeUp

Computes the vertex up-vector for the given heightmap coordinates.

[ThreadSafe]
public virtual method	ComputeUp (float64 heightmapX, float64 heightmapY, float64 heightmapZ)
type	Vec3D
params	heightmapX		The heightmap X-coordinate.
	heightmapY		The heightmap Y-coordinate.
	heightmapZ		The heightmap Z-coordinate.
returns			The unit-length vertex up-vector.
inherited	GeometryBase.ComputeUp

ToHandedness

Transforms this geometry to the given handedness by flipping the Z-axis if necessary.

public virtual method	ToHandedness (CartesianHandedness handedness)
type	IGeometry
params	handedness		The requested handedness.
returns		[not-null]	The resulting geometry.
inherited	GeometryBase.ToHandedness

Transform

Creates a geometry that transforms the output coordinates of this geometry with the given matrix.

public virtual method	Transform (Mat4D matrix)
type	IGeometry
params	matrix		The transformation matrix.
returns		[not-null]	The resulting geometry.
inherited	GeometryBase.Transform

Protected / Constructors

Geometry

Creates a new instance of Geometry for Cube.

protected constructor	Geometry (int32 size)
params	size	[pow2+1]	The map size.

---

Creates a new instance of Geometry for Rect.

protected constructor	Geometry (int32 width, int32 height)
params	width	[>0]	The map width.
	height	[>0]	The map height.