Triangle mesh representation of a terrain surface. More...

#include <terrain_tri_mesh.hpp>

Classes
struct	BoundingBox
	Axis-aligned 2D bounding box. More...

struct	Edge
	Undirected edge between two vertices. More...

struct	EdgeHash
	Hash functor for Edge. More...

struct	Neighbor
	Neighbor vertex information. More...

struct	NeighborData
	Vertex adjacency lists. More...

struct	ShortestPathResult
	Result of a shortest-path computation. More...

struct	Triangle
	Triangle defined by three vertex indices. More...

Public Member Functions
	TerrainTriMesh ()=default
	Construct an empty mesh.

	TerrainTriMesh (const std::vector< glm::vec3 > &ref_points)
	Construct a mesh from 3D points.

	TerrainTriMesh (const std::vector< float > &x, const std::vector< float > &y, const std::vector< float > &z)
	Construct a mesh from coordinate arrays.

void	triangulate_delaunay ()
	Build the Delaunay triangulation.

void	compute_neighbors ()
	Compute vertex adjacency.

void	compute_gradients ()
	Compute vertex gradients.

void	relax_xy (float lambda=0.5f, int iterations=1, bool preserve_chull=true)
	Relax vertex positions in the XY plane.

void	relax_xyz (float lambda=0.5f, int iterations=1, bool preserve_chull=true)
	Relax vertex positions in 3D.

void	relax_xyz_taubin (float lambda=0.5f, float mu=-0.55f, int iterations=1, bool preserve_chull=true)
	Apply Taubin smoothing.

void	remap_z (float vmin=0.f, float vmax=1.f)
	Remap elevation values.

void	slope_limiter (float max_slope, int iterations=10, float sigma=0.1f)
	Limit terrain slopes.

void	slope_limiter (const std::vector< float > &max_slope, int iterations=10, float sigma=0.1f)
	Limit terrain slopes with per-vertex thresholds.

void	subdivise ()
	Subdivide mesh triangles.

void	flow_breach (float epsilon, float uphill_tolerance=0.f)
	Breach terrain depressions for flow routing.

bool	barycentric (const glm::vec2 &p, size_t i0, size_t i1, size_t i2, float &w0, float &w1, float &w2) const
	Compute barycentric coordinates.

int	find_triangle (const glm::vec2 &p, int start_tri=0, bool linear_search=false) const
	Find the triangle containing a point.

int	neighbor_triangle (int tri_index, int edge_index) const
	Return the neighboring triangle across an edge.

float	interpolate_z_linear (const glm::vec2 &p, int &last_tri, float fill_value=0.f) const
	Linearly interpolate elevation.

float	interpolate_z_linear_gradient (const glm::vec2 &p, int &last_tri, float fill_value=0.f, float gradient_scaling=1.f) const
	Gradient-enhanced linear interpolation.

float	interpolate_z_nearest (const glm::vec2 &p) const
	Nearest-neighbor interpolation.

float	interpolate_z_nearest_approx (const glm::vec2 &p, int &last_tri, float fill_value=0.f) const
	Approximate nearest-neighbor interpolation.

BoundingBox	get_bbox () const
	Return the mesh bounding box.

glm::vec2	get_range_z () const
	Return the elevation range.

glm::vec3	get_reference_lengths () const
	Return reference mesh dimensions.

std::vector< float >	get_vertex_areas (bool normalized) const
	Compute vertex areas.

float	get_reference_area_xy () const
	Return the projected mesh area.

float	get_reference_area () const
	Return the mesh surface area.

size_t	size () const
	Return the number of vertices.

ShortestPathResult	compute_shortest_paths_to_hull (bool use_delta_z=false, float elevation_weight=1.f) const
	Compute shortest paths to the convex hull.

ShortestPathResult	compute_shortest_paths (size_t start, bool use_delta_z=false, float elevation_weight=1.f) const
	Compute shortest paths from a source vertex.

std::vector< size_t >	shortest_path (size_t start, size_t end, bool use_delta_z=false, float elevation_weight=1.f) const
	Compute the shortest path between two vertices.

std::vector< size_t >	path_to_hull (size_t start, const ShortestPathResult &result) const
	Reconstruct a path to the convex hull.

const std::vector< glm::vec3 > &	get_points () const
	Return mesh vertices.

std::vector< glm::vec3 > &	get_points ()
	Return mesh vertices.

const std::vector< Triangle > &	get_triangles () const
	Return mesh triangles.

const std::vector< size_t > &	get_convex_hull () const
	Return convex hull vertex indices.

const NeighborData &	get_neighbors () const
	Return vertex neighbors.

bool	export_obj (const std::string &filepath) const
	Export the mesh as an OBJ file.

std::string	info_string () const
	Return a mesh summary string.

void	print_info () const
	Print mesh information.

Array	to_array (const glm::ivec2 &shape, const std::vector< float > &values={}, const glm::vec4 &bbox={0.f, 1.f, 0.f, 1.f}) const
	Rasterize the mesh into an array.

void	to_csv (const std::string &fname) const
	Export vertices to CSV.

Detailed Description

Triangle mesh representation of a terrain surface.

Stores vertices, triangulation, connectivity, and provides geometry, interpolation, smoothing, and pathfinding utilities.

Constructor & Destructor Documentation

◆ TerrainTriMesh() [1/3]

hmap::TerrainTriMesh::TerrainTriMesh ( )

default

Construct an empty mesh.

◆ TerrainTriMesh() [2/3]

hmap::TerrainTriMesh::TerrainTriMesh ( const std::vector< glm::vec3 > & ref_points )

Construct a mesh from 3D points.

◆ TerrainTriMesh() [3/3]

hmap::TerrainTriMesh::TerrainTriMesh	(	const std::vector< float > &	x,
		const std::vector< float > &	y,
		const std::vector< float > &	z
	)

Construct a mesh from coordinate arrays.

Member Function Documentation

◆ triangulate_delaunay()

void hmap::TerrainTriMesh::triangulate_delaunay ( )

Build the Delaunay triangulation.

◆ compute_neighbors()

void hmap::TerrainTriMesh::compute_neighbors ( )

Compute vertex adjacency.

◆ compute_gradients()

void hmap::TerrainTriMesh::compute_gradients ( )

Compute vertex gradients.

◆ relax_xy()

void hmap::TerrainTriMesh::relax_xy	(	float	lambda = `0.5f`,
		int	iterations = `1`,
		bool	preserve_chull = `true`
	)

Relax vertex positions in the XY plane.

◆ relax_xyz()

void hmap::TerrainTriMesh::relax_xyz	(	float	lambda = `0.5f`,
		int	iterations = `1`,
		bool	preserve_chull = `true`
	)

Relax vertex positions in 3D.

◆ relax_xyz_taubin()

void hmap::TerrainTriMesh::relax_xyz_taubin	(	float	lambda = `0.5f`,
		float	mu = `-0.55f`,
		int	iterations = `1`,
		bool	preserve_chull = `true`
	)

Apply Taubin smoothing.

◆ remap_z()

void hmap::TerrainTriMesh::remap_z	(	float	vmin = `0.f`,
		float	vmax = `1.f`
	)

Remap elevation values.

◆ slope_limiter() [1/2]

void hmap::TerrainTriMesh::slope_limiter	(	float	max_slope,
		int	iterations = `10`,
		float	sigma = `0.1f`
	)

Limit terrain slopes.

◆ slope_limiter() [2/2]

void hmap::TerrainTriMesh::slope_limiter	(	const std::vector< float > &	max_slope,
		int	iterations = `10`,
		float	sigma = `0.1f`
	)

Limit terrain slopes with per-vertex thresholds.

◆ subdivise()

void hmap::TerrainTriMesh::subdivise ( )

Subdivide mesh triangles.

◆ flow_breach()

void hmap::TerrainTriMesh::flow_breach	(	float	epsilon,
		float	uphill_tolerance = `0.f`
	)

Breach terrain depressions for flow routing.

◆ barycentric()

bool hmap::TerrainTriMesh::barycentric	(	const glm::vec2 &	p,
		size_t	i0,
		size_t	i1,
		size_t	i2,
		float &	w0,
		float &	w1,
		float &	w2
	)		const

Compute barycentric coordinates.

◆ find_triangle()

int hmap::TerrainTriMesh::find_triangle	(	const glm::vec2 &	p,
		int	start_tri = `0`,
		bool	linear_search = `false`
	)		const

Find the triangle containing a point.

◆ neighbor_triangle()

int hmap::TerrainTriMesh::neighbor_triangle	(	int	tri_index,
		int	edge_index
	)		const

Return the neighboring triangle across an edge.

◆ interpolate_z_linear()

float hmap::TerrainTriMesh::interpolate_z_linear	(	const glm::vec2 &	p,
		int &	last_tri,
		float	fill_value = `0.f`
	)		const

Linearly interpolate elevation.

◆ interpolate_z_linear_gradient()

float hmap::TerrainTriMesh::interpolate_z_linear_gradient	(	const glm::vec2 &	p,
		int &	last_tri,
		float	fill_value = `0.f`,
		float	gradient_scaling = `1.f`
	)		const

Gradient-enhanced linear interpolation.

◆ interpolate_z_nearest()

float hmap::TerrainTriMesh::interpolate_z_nearest ( const glm::vec2 & p ) const

Nearest-neighbor interpolation.

◆ interpolate_z_nearest_approx()

float hmap::TerrainTriMesh::interpolate_z_nearest_approx	(	const glm::vec2 &	p,
		int &	last_tri,
		float	fill_value = `0.f`
	)		const

Approximate nearest-neighbor interpolation.

◆ get_bbox()

TerrainTriMesh::BoundingBox hmap::TerrainTriMesh::get_bbox ( ) const

Return the mesh bounding box.

◆ get_range_z()

glm::vec2 hmap::TerrainTriMesh::get_range_z ( ) const

Return the elevation range.

◆ get_reference_lengths()

glm::vec3 hmap::TerrainTriMesh::get_reference_lengths ( ) const

Return reference mesh dimensions.

◆ get_vertex_areas()

std::vector< float > hmap::TerrainTriMesh::get_vertex_areas ( bool normalized ) const

Compute vertex areas.

◆ get_reference_area_xy()

float hmap::TerrainTriMesh::get_reference_area_xy ( ) const

Return the projected mesh area.

◆ get_reference_area()

float hmap::TerrainTriMesh::get_reference_area ( ) const

Return the mesh surface area.

◆ size()

size_t hmap::TerrainTriMesh::size ( ) const

Return the number of vertices.

◆ compute_shortest_paths_to_hull()

TerrainTriMesh::ShortestPathResult hmap::TerrainTriMesh::compute_shortest_paths_to_hull	(	bool	use_delta_z = `false`,
		float	elevation_weight = `1.f`
	)		const

Compute shortest paths to the convex hull.

◆ compute_shortest_paths()

TerrainTriMesh::ShortestPathResult hmap::TerrainTriMesh::compute_shortest_paths	(	size_t	start,
		bool	use_delta_z = `false`,
		float	elevation_weight = `1.f`
	)		const

Compute shortest paths from a source vertex.

◆ shortest_path()

std::vector< size_t > hmap::TerrainTriMesh::shortest_path	(	size_t	start,
		size_t	end,
		bool	use_delta_z = `false`,
		float	elevation_weight = `1.f`
	)		const

Compute the shortest path between two vertices.

◆ path_to_hull()

std::vector< size_t > hmap::TerrainTriMesh::path_to_hull	(	size_t	start,
		const ShortestPathResult &	result
	)		const

Reconstruct a path to the convex hull.

◆ get_points() [1/2]

const std::vector< glm::vec3 > & hmap::TerrainTriMesh::get_points ( ) const

Return mesh vertices.

◆ get_points() [2/2]

std::vector< glm::vec3 > & hmap::TerrainTriMesh::get_points ( )

Return mesh vertices.

◆ get_triangles()

const std::vector< TerrainTriMesh::Triangle > & hmap::TerrainTriMesh::get_triangles ( ) const

Return mesh triangles.

◆ get_convex_hull()

const std::vector< size_t > & hmap::TerrainTriMesh::get_convex_hull ( ) const

Return convex hull vertex indices.

◆ get_neighbors()

const TerrainTriMesh::NeighborData & hmap::TerrainTriMesh::get_neighbors ( ) const

Return vertex neighbors.

◆ export_obj()

bool hmap::TerrainTriMesh::export_obj ( const std::string & filepath ) const

Export the mesh as an OBJ file.

◆ info_string()

std::string hmap::TerrainTriMesh::info_string ( ) const

Return a mesh summary string.

◆ print_info()

void hmap::TerrainTriMesh::print_info ( ) const

Print mesh information.

◆ to_array()

Array hmap::TerrainTriMesh::to_array	(	const glm::ivec2 &	shape,
		const std::vector< float > &	values = `{}`,
		const glm::vec4 &	bbox = `{0.f, 1.f, 0.f, 1.f}`
	)		const

Rasterize the mesh into an array.

◆ to_csv()

void hmap::TerrainTriMesh::to_csv ( const std::string & fname ) const

Export vertices to CSV.

The documentation for this class was generated from the following files:

HighMap/include/highmap/terrain_tri_mesh.hpp
HighMap/src/terrain_tri_mesh/flow_breach.cpp
HighMap/src/terrain_tri_mesh/shortest_path.cpp
HighMap/src/terrain_tri_mesh/terrain_tri_mesh.cpp

Classes

Public Member Functions