QgsTriangularMesh class

Triangular/Derived Mesh is mesh with vertices in map coordinates.

It creates spatial index for identification of a triangle that contains a particular point on the map.

Constructors, destructors, conversion operators

auto centroids() const -> const QVector<QgsMeshVertex>&: Returns centroids of the native faces in map CRS.
auto faceIndexesForRectangle(const QgsRectangle& rectangle) const -> QList<int>: Finds indexes of triangles intersecting given bounding box It uses spatial indexing.
auto faceIndexForPoint(const QgsPointXY& point) const -> int: Finds index of triangle at given point It uses spatial indexing.
auto triangles() const -> const QVector<QgsMeshFace>&: Returns triangles.
auto trianglesToNativeFaces() const -> const QVector<int>&: Returns mapping between triangles and original faces.
void update(QgsMesh* nativeMesh, QgsRenderContext* context): Constructs triangular mesh from layer's native mesh and context.
auto vertices() const -> const QVector<QgsMeshVertex>&: Returns vertices in map coordinate system.

Finds indexes of triangles intersecting given bounding box It uses spatial indexing.

Parameters
rectangle	bounding box in map coordinate system
Returns	triangle indexes that intersect the rectangle

Finds index of triangle at given point It uses spatial indexing.

Parameters
point	point in map coordinate system
Returns	triangle index that contains the given point, -1 if no such triangle exists

Constructs triangular mesh from layer's native mesh and context.

Parameters
nativeMesh	QgsMesh to access native vertices and faces
context	Rendering context to estimate number of triagles to create for an face

Populates spatial index.

Returns vertices in map coordinate system.

The list of consist of vertices from native mesh (0-N) and extra vertices needed to create triangles (N+1 - len)