Implements CSG objects and instructions. More...

#include <geogram/mesh/mesh_CSG.h>

Public Member Functions
CSGMesh_var	square (vec2 size=vec2(1.0, 1.0), bool center=true)

CSGMesh_var	circle (double r=1.0)

CSGMesh_var	cube (vec3 size=vec3(1.0, 1.0, 1.0), bool center=true)

CSGMesh_var	sphere (double r=1.0)

CSGMesh_var	cylinder (double h=1.0, double r1=1.0, double r2=1.0, bool center=true)

CSGMesh_var	import (const std::string &filename, const std::string &layer="", index_t timestamp=0, vec2 origin=vec2(0.0, 0.0), vec2 scale=vec2(1.0, 1.0))

CSGMesh_var	surface (const std::string &filename, bool center, bool invert)

CSGMesh_var	multmatrix (const mat4 &M, const CSGScope &scope)
	Groups several meshes into a single one and transforms them. More...

CSGMesh_var	union_instr (const CSGScope &scope)
	Computes the union of two or more meshes. More...

CSGMesh_var	intersection (const CSGScope &scope)
	Computes the intersection between two or more meshes. More...

CSGMesh_var	difference (const CSGScope &scope)
	Computes the intersection between two meshes. More...

CSGMesh_var	group (const CSGScope &scope)
	synonym for union. More...

CSGMesh_var	color (vec4 color, const CSGScope &scope)
	Groups several meshes into a single one and sets their color. More...

CSGMesh_var	hull (const CSGScope &scope)
	Computes the convex hull of several meshes. More...

CSGMesh_var	linear_extrude (const CSGScope &scope, double height=1.0, bool center=true, vec2 scale=vec2(1.0, 1.0), index_t slices=0, double twist=0.0)
	Computes a 3D extrusion from a 2D shape. More...

CSGMesh_var	rotate_extrude (const CSGScope &scope, double angle=360.0)
	Computes a 3D extrusion from a 2D shape. More...

CSGMesh_var	projection (const CSGScope &scope, bool cut)
	Creates a 2D mesh from 3D mesh. More...

CSGMesh_var	append (const CSGScope &scope)
	Appends all meshes in scope into a unique mesh, without testing for intersections.

void	reset_defaults ()
	Resets defaults value for fn, fs, fa. More...

void	set_fn (double fn)
	Sets the number of fragments. More...

void	set_fs (double fs)
	Sets the minimum size for a fragment. More...

void	set_fa (double fa)
	Sets the minimum angle for a fragment. More...

void	set_delaunay (bool x)
	If set, compute constrained Delaunay triangulation in the intersected triangles. If there are intersections in coplanar facets, it guarantees uniqueness of their triangulation. Default is set.

void	set_detect_intersecting_neighbors (bool x)
	detect and compute intersections between facets that share a facet or an edge. Set to false if input is a set of conformal meshes. Default is set.

void	set_simplify_coplanar_facets (bool x, double angle_tolerance=0.0)
	Specifies whether coplanar facets should be simplified. More...

void	set_fast_union (bool x)
	Sets fast union mode. More...

void	set_verbose (bool x)
	Displays (lots of) additional information. More...

bool	verbose () const
	Tests wheter verbose mode is set. More...

void	add_file_path (const std::string &path)
	Adds a path to the file path. More...

void	reset_file_path ()
	Resets the file path to its default value, with only the current directory ".".

Static Public Attributes
static constexpr double	DEFAULT_FA = 12.0

static constexpr double	DEFAULT_FS = 2.0

static constexpr double	DEFAULT_FN = 0.0

Protected Member Functions
bool	find_file (std::string &filename)

void	do_CSG (CSGMesh_var mesh, const std::string &boolean_expr)

void	triangulate (CSGMesh_var mesh, const std::string &boolean_expr, bool keep_border_only=false)
	Triangulates a 2D mesh. More...

CSGMesh_var	import_with_openSCAD (const std::string &filename, const std::string &layer="", index_t timestamp=0)
	For the file formats that are not supported by geogram, get help from OpenSCAD to convert them. More...

Image *	load_dat_image (const std::string &file_name)
	Loads an ascii data file as an image. More...

void	post_process (CSGMesh_var mesh)
	Post-processes the result of a previous intersection. More...

index_t	get_fragments_from_r (double r, double twist=360.0)
	Computes the number of fragments, that is, edges in a polygonal approximation of a circle. More...

Detailed Description

Implements CSG objects and instructions.

Can be used to construct volumes in C++ with a syntax very similar to OpenSCAD .csg files.

Definition at line 134 of file mesh_CSG.h.

Member Function Documentation

◆ add_file_path()

void GEO::CSGBuilder::add_file_path ( const std::string & path )

inline

Adds a path to the file path.

The file path is where import() searches files. The default file path contains the current directory "."

Parameters

[in] path the file path to be added, without trailing '/'

Definition at line 373 of file mesh_CSG.h.

◆ color()

CSGMesh_var GEO::CSGBuilder::color	(	vec4	color,
		const CSGScope &	scope
	)

Groups several meshes into a single one and sets their color.

Parameters

[in] color the color, as r,g,b,a.

ignored for now, just behaves as group().

◆ difference()

CSGMesh_var GEO::CSGBuilder::difference ( const CSGScope & scope )

Computes the intersection between two meshes.

If scope contains more than two meshes, it computes the difference between the first mesh and the union of the rest.

Parameters

[in] scope the meshes

◆ get_fragments_from_r()

index_t GEO::CSGBuilder::get_fragments_from_r	(	double	r,
		double	twist = `360.0`
	)

protected

Computes the number of fragments, that is, edges in a polygonal approximation of a circle.

Parameters

[in]	r	the radius of the circle
[in]	twist	the portion of the circle that will be drawn, in degrees

Uses fn,fs,fa

See also: set_fn(), set_fs(), set_fa()

◆ group()

CSGMesh_var GEO::CSGBuilder::group ( const CSGScope & scope )

inline

synonym for union.

Maybe there's something I did not understand in OpenSCAD, but I do not see the difference between group and union.

Definition at line 204 of file mesh_CSG.h.

◆ hull()

CSGMesh_var GEO::CSGBuilder::hull ( const CSGScope & scope )

Computes the convex hull of several meshes.

Parameters

[in] scope the meshes

◆ import_with_openSCAD()

CSGMesh_var GEO::CSGBuilder::import_with_openSCAD	(	const std::string &	filename,
		const std::string &	layer = `""`,
		index_t	timestamp = `0`
	)

protected

For the file formats that are not supported by geogram, get help from OpenSCAD to convert them.

Converts STEP files.

◆ intersection()

CSGMesh_var GEO::CSGBuilder::intersection ( const CSGScope & scope )

Computes the intersection between two or more meshes.

Parameters

[in] scope the meshes

◆ linear_extrude()

CSGMesh_var GEO::CSGBuilder::linear_extrude	(	const CSGScope &	scope,
		double	height = `1.0`,
		bool	center = `true`,
		vec2	scale = `vec2(1.0, 1.0)`,
		index_t	slices = `0`,
		double	twist = `0.0`
	)

Computes a 3D extrusion from a 2D shape.

Parameters

[in]	scope	one or more 2D shapes
[in]	height	total height of the extrusion
[in]	center	if set, z will go from -height/2 to height/2, else from 0 to height
[in]	scale	scaling factor to be applied to x and y coordinates when reaching `height`
[in]	slices	number of slices along the z axis
[in]	twist	rotation to be applied when sweeping, in degrees

◆ load_dat_image()

Image* GEO::CSGBuilder::load_dat_image ( const std::string & file_name )

protected

Loads an ascii data file as an image.

Parameters

[in] file_name the name of the file, containing a matrix in the octave file format

Returns: a pointer to the created image. Color encoding is Image::GRAY and component encoding is Image::FLOAT64.

◆ multmatrix()

CSGMesh_var GEO::CSGBuilder::multmatrix	(	const mat4 &	M,
		const CSGScope &	scope
	)

Groups several meshes into a single one and transforms them.

Parameters

[in]	M	the transformation matrix. It follows the same convention as OpenSCAD, that is, not the OpenGL convention. For instance, a translation matrix has the translation vector as its third column.
[in]	scope	one or several meshes to be merged.

◆ post_process()

void GEO::CSGBuilder::post_process ( CSGMesh_var mesh )

protected

Post-processes the result of a previous intersection.

After converting exact coordinates to doubles, some problems may occur. This function tentatively fixes this problems. TODO: correct snap-rounding.

Parameters

[in] mesh the mesh to be processed

◆ projection()

CSGMesh_var GEO::CSGBuilder::projection	(	const CSGScope &	scope,
		bool	cut
	)

Creates a 2D mesh from 3D mesh.

Parameters

[in] cut if set, computes the boundary of the intersection between the object and the X,Y plane, else computes the boundary of the projection.

◆ reset_defaults()

void GEO::CSGBuilder::reset_defaults ( )

Resets defaults value for fn, fs, fa.

See also: set_fn(), set_fs(), set_fa()

◆ rotate_extrude()

CSGMesh_var GEO::CSGBuilder::rotate_extrude	(	const CSGScope &	scope,
		double	angle = `360.0`
	)

Computes a 3D extrusion from a 2D shape.

Parameters

[in]	scope	one or more 2D shapes. Everything should be on the same side of the Y axis, preferably the positive side.
[in]	angle	optional angle

◆ set_fa()

void GEO::CSGBuilder::set_fa ( double fa )

inline

Sets the minimum angle for a fragment.

Parameters

[in] fa minimum angle for a fragment, in degrees.

This determines the number of edges in a polygonal approximation of a circle.

Definition at line 301 of file mesh_CSG.h.

◆ set_fast_union()

void GEO::CSGBuilder::set_fast_union ( bool x )

inline

Sets fast union mode.

In fast union mode, all intersections are computed and the external shell is kept. It may give incorrect result if an object is floating inside another one (completely included).

Parameters

[in] x true if fast union mode should be used, false otherwise.

Definition at line 345 of file mesh_CSG.h.

◆ set_fn()

void GEO::CSGBuilder::set_fn ( double fn )

inline

Sets the number of fragments.

This corresponds to the number of edges in a polygonal approximation of a circle. If left to 0, it is automatically computed from fs and fa

Parameters

[in] fn the number of fragments.

See also: set_fs(), set_fa()

Definition at line 281 of file mesh_CSG.h.

◆ set_fs()

void GEO::CSGBuilder::set_fs ( double fs )

inline

Sets the minimum size for a fragment.

Parameters

[in] fs minimum size for a fragment.

This determines the number of edges in a polygonal approximation of a circle.

Definition at line 291 of file mesh_CSG.h.

◆ set_simplify_coplanar_facets()

void GEO::CSGBuilder::set_simplify_coplanar_facets	(	bool	x,
		double	angle_tolerance = `0.0`
	)

inline

Specifies whether coplanar facets should be simplified.

Parameters

[in]	x	if set, coplanar facets are simplified, else they are kept as is (faster but generates many triangles). Default is set.
[in]	angle_tolerance	(in degree) the pairs of adjacent facets with normals that make an angle smaller than this threshold as considered to be coplanar.

Definition at line 333 of file mesh_CSG.h.

◆ set_verbose()

void GEO::CSGBuilder::set_verbose ( bool x )

inline

Displays (lots of) additional information.

Parameters

[in] x whether additional information should be displayed. Default is off

Definition at line 354 of file mesh_CSG.h.

◆ triangulate()

void GEO::CSGBuilder::triangulate	(	CSGMesh_var	mesh,
		const std::string &	boolean_expr,
		bool	keep_border_only = `false`
	)

protected

Triangulates a 2D mesh.

Parameters

[in,out]	mesh	the input is a set of vertices and edges. The output has a set of triangles inside.
[in]	keep_border_only	if set, then triangles are discarded. It useful to compute 2D boolean operations, where only the border is kept.

◆ union_instr()

CSGMesh_var GEO::CSGBuilder::union_instr ( const CSGScope & scope )

Computes the union of two or more meshes.

Parameters

[in] scope the meshes

◆ verbose()

bool GEO::CSGBuilder::verbose ( ) const

inline

Tests wheter verbose mode is set.

Return values

true	if additional information will be displayed.
false	otherwise.

Definition at line 363 of file mesh_CSG.h.

Member Data Documentation

◆ DEFAULT_FA

constexpr double GEO::CSGBuilder::DEFAULT_FA = 12.0

staticconstexpr

See also: set_fa()

Definition at line 137 of file mesh_CSG.h.

◆ DEFAULT_FN

constexpr double GEO::CSGBuilder::DEFAULT_FN = 0.0

staticconstexpr

See also: set_fn()

Definition at line 143 of file mesh_CSG.h.

◆ DEFAULT_FS

constexpr double GEO::CSGBuilder::DEFAULT_FS = 2.0

staticconstexpr

See also: set_fs()

Definition at line 140 of file mesh_CSG.h.

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

geogram/mesh/mesh_CSG.h

Public Member Functions

Static Public Attributes

Protected Member Functions

Detailed Description

Member Function Documentation

◆ add_file_path()

◆ color()

◆ difference()

◆ get_fragments_from_r()

◆ group()

◆ hull()

◆ import_with_openSCAD()

◆ intersection()

◆ linear_extrude()

◆ load_dat_image()

◆ multmatrix()

◆ post_process()

◆ projection()

◆ reset_defaults()

◆ rotate_extrude()

◆ set_fa()

◆ set_fast_union()

◆ set_fn()

◆ set_fs()

◆ set_simplify_coplanar_facets()

◆ set_verbose()

◆ triangulate()

◆ union_instr()

◆ verbose()

Member Data Documentation

◆ DEFAULT_FA

◆ DEFAULT_FN

◆ DEFAULT_FS