Class: QgsTessellator

class qgis.core.QgsTessellator(originX: float, originY: float, addNormals: bool, invertNormals: bool = False, addBackFaces: bool = False, noZ: bool = False, addTextureCoords: bool = False, facade: int = 3, textureRotation: float = 0)

Bases: sip.wrapper

Creates tessellator with a specified origin point of the world (in map coordinates)

QgsTessellator(bounds: QgsRectangle, addNormals: bool, invertNormals: bool = False, addBackFaces: bool = False, noZ: bool = False, addTextureCoords: bool = False, facade: int = 3, textureRotation: float = 0) Creates tessellator with a specified bounds of input geometry coordinates. This constructor allows the tessellator to map input coordinates to a desirable range for numerical stability during calculations.

If noZ is True, then a 2-dimensional tessellation only will be performed and all z coordinates will be ignored.

New in version 3.10.

QgsTessellator(QgsTessellator)

Class that takes care of tessellation of polygons into triangles.

It is expected that client code will create the tessellator object, then repeatedly call addPolygon() method that will generate triangles, and finally call data() to get final vertex data.

Optionally provides extrusion by adding triangles that serve as walls when extrusion height is non-zero.

New in version 3.4:

Methods

addPolygon

Tessellates a triangle and adds its vertex entries to the output data array

data

Returns array of triangle vertex data

dataVerticesCount

Returns the number of vertices stored in the output data array

stride

Returns size of one vertex entry in bytes

zMaximum

Returns maximal Z value of the data (in world coordinates)

zMinimum

Returns minimal Z value of the data (in world coordinates)

addPolygon(self, polygon: QgsPolygon, extrusionHeight: float)

Tessellates a triangle and adds its vertex entries to the output data array

Parameters
  • polygon (QgsPolygon) –

  • extrusionHeight (float) –

data(self) List[float]

Returns array of triangle vertex data

Vertice coordinates are stored as (x, z, -y)

Return type

List[float]

dataVerticesCount(self) int

Returns the number of vertices stored in the output data array

Return type

int

stride(self) int

Returns size of one vertex entry in bytes

Return type

int

zMaximum(self) float

Returns maximal Z value of the data (in world coordinates)

New in version 3.12.

Return type

float

zMinimum(self) float

Returns minimal Z value of the data (in world coordinates)

New in version 3.12.

Return type

float