Functions for mesh intersections. More...

#include <imesh/imesh_mesh.h>
#include <vgl/vgl_vector_3d.h>
#include <vcl_limits.h>

Functions
bool	imesh_intersect_triangle (const vgl_point_3d< double > &p, const vgl_vector_3d< double > &d, const vgl_point_3d< double > &a, const vgl_point_3d< double > &b, const vgl_point_3d< double > &c, double &dist, double &u, double &v)
	Intersect the ray from point p with direction d and the triangle defined by a,b,c.
bool	imesh_intersect_triangle (const vgl_point_3d< double > &p, const vgl_vector_3d< double > &d, const vgl_point_3d< double > &a, const vgl_point_3d< double > &b, const vgl_point_3d< double > &c, const vgl_vector_3d< double > &n, double &dist, double &u, double &v)
	Intersect the ray from point p with direction d and the triangle defined by a,b,c.
bool	imesh_intersect_triangle_min_dist (const vgl_point_3d< double > &p, const vgl_vector_3d< double > &d, const vgl_point_3d< double > &a, const vgl_point_3d< double > &b, const vgl_point_3d< double > &c, const vgl_vector_3d< double > &n, double &dist, double &u, double &v)
	Intersect the ray from point p with direction d and the triangle defined by a,b,c.
int	imesh_intersect_min_dist (const vgl_point_3d< double > &p, const vgl_vector_3d< double > &d, const imesh_mesh &mesh, double &dist, double u=0, double v=0)
	Intersect the ray from point p with direction d and the triangulated mesh.
unsigned char	imesh_triangle_closest_point (const vgl_point_3d< double > &p, const vgl_point_3d< double > &a, const vgl_point_3d< double > &b, const vgl_point_3d< double > &c, const vgl_vector_3d< double > &n, double &dist, double &u, double &v)
	Find the closest point on the triangle a,b,c to point p.
unsigned char	imesh_triangle_closest_point (const vgl_point_3d< double > &p, const vgl_point_3d< double > &a, const vgl_point_3d< double > &b, const vgl_point_3d< double > &c, double &dist, double &u, double &v)
	Find the closest point on the triangle a,b,c to point p.
vgl_point_3d< double >	imesh_triangle_closest_point (const vgl_point_3d< double > &p, const vgl_point_3d< double > &a, const vgl_point_3d< double > &b, const vgl_point_3d< double > &c, double &dist)
	Find the closest point on the triangle a,b,c to point p.
int	imesh_closest_point (const vgl_point_3d< double > &p, const imesh_mesh &mesh, vgl_point_3d< double > &cp, double u=0, double v=0)
	Find the closest point on the triangulated mesh to point p.
unsigned char	imesh_triangle_intersect (const vgl_point_2d< double > &p, const vgl_vector_2d< double > &d, const vgl_point_2d< double > &a, const vgl_point_2d< double > &b, const vgl_point_2d< double > &c, double &u, double &v)
	Find the closest intersection point from p along d with triangle a,b,c.
unsigned char	imesh_triangle_intersect (double &u, double &v, const double &du, const double &dv, const double &eps=vcl_numeric_limits< double >::epsilon())
	Find the closest intersection point along the vector (du,dv).

Detailed Description

Functions for mesh intersections.

Author:: Matt Leotta (mleotta@lems.brown.edu)

Date:: May 9, 2008

    Modifications
     <none yet>

Definition in file imesh_intersect.h.

Function Documentation

int imesh_closest_point	(	const vgl_point_3d< double > &	p,
		const imesh_mesh &	mesh,
		vgl_point_3d< double > &	cp,
		double *	u,
		double *	v
	)

Find the closest point on the triangulated mesh to point p.

Returns:: the face index of the closest triangle (one of them if on an edge or vertex)

Parameters:

cp	is the closest point on the mesh (returned by reference)
u	and
v	(optional) are the barycentric coordinates of the closest point

Definition at line 317 of file imesh_intersect.cxx.

int imesh_intersect_min_dist	(	const vgl_point_3d< double > &	p,
		const vgl_vector_3d< double > &	d,
		const imesh_mesh &	mesh,
		double &	dist,
		double *	u,
		double *	v
	)

Intersect the ray from point p with direction d and the triangulated mesh.

Returns:: the face index of the closest intersecting triangle

Parameters:

dist	is the distance to the triangle (returned by reference)
u	and
v	(optional) are the barycentric coordinates of the intersection

Definition at line 136 of file imesh_intersect.cxx.

bool imesh_intersect_triangle	(	const vgl_point_3d< double > &	p,
		const vgl_vector_3d< double > &	d,
		const vgl_point_3d< double > &	a,
		const vgl_point_3d< double > &	b,
		const vgl_point_3d< double > &	c,
		double &	dist,
		double &	u,
		double &	v
	)

Intersect the ray from point p with direction d and the triangle defined by a,b,c.

Returns:: true if intersection occurs

Parameters:

dist	is the distance to the triangle (returned by reference)
u	and
v	are the barycentric coordinates of the intersection Barycentric coordinates are u and v such that (1-u-v)a + ub + vc = p+distd

Returns:: true if intersection occurs

Parameters:

dist	is the distance to the triangle (returned by reference)
u	and
v	are the barycentric coordinates of the intersection

Definition at line 39 of file imesh_intersect.cxx.

bool imesh_intersect_triangle	(	const vgl_point_3d< double > &	p,
		const vgl_vector_3d< double > &	d,
		const vgl_point_3d< double > &	a,
		const vgl_point_3d< double > &	b,
		const vgl_point_3d< double > &	c,
		const vgl_vector_3d< double > &	n,
		double &	dist,
		double &	u,
		double &	v
	)

Intersect the ray from point p with direction d and the triangle defined by a,b,c.

The un-normalized normal vector (b-a)x(c-a) is precomputed and also passed in

Returns:: true if intersection occurs

Parameters:

dist	is the distance to the triangle (returned by reference)
u	and
v	are the barycentric coordinates of the intersection

Definition at line 57 of file imesh_intersect.cxx.

bool imesh_intersect_triangle_min_dist	(	const vgl_point_3d< double > &	p,
		const vgl_vector_3d< double > &	d,
		const vgl_point_3d< double > &	a,
		const vgl_point_3d< double > &	b,
		const vgl_point_3d< double > &	c,
		const vgl_vector_3d< double > &	n,
		double &	dist,
		double &	u,
		double &	v
	)

Intersect the ray from point p with direction d and the triangle defined by a,b,c.

The un-normalized normal vector (b-a)x(c-a) is precomputed and also passed in

Returns:: true if intersection occurs and the new dist is less than the old distance (but > 0)

Parameters:

dist	is the distance to the triangle (returned by reference)
u	and
v	are the barycentric coordinates of the intersection

Definition at line 97 of file imesh_intersect.cxx.

unsigned char imesh_triangle_closest_point	(	const vgl_point_3d< double > &	p,
		const vgl_point_3d< double > &	a,
		const vgl_point_3d< double > &	b,
		const vgl_point_3d< double > &	c,
		const vgl_vector_3d< double > &	n,
		double &	dist,
		double &	u,
		double &	v
	)

Find the closest point on the triangle a,b,c to point p.

The un-normalized normal vector (b-a)x(c-a) is precomputed and also passed in

Returns:

a code indicating that the closest point:

0 does not exist (should not occur)
1 is a
2 is b
3 is on the edge from a to b
4 is c
5 is on the edge from a to c
6 is on the edge from b to c
7 is on the face of the triangle

Parameters:

dist	is the distance to the triangle (returned by reference)
u	and
v	are the barycentric coordinates of the closest point

Definition at line 185 of file imesh_intersect.cxx.

unsigned char imesh_triangle_closest_point	(	const vgl_point_3d< double > &	p,
		const vgl_point_3d< double > &	a,
		const vgl_point_3d< double > &	b,
		const vgl_point_3d< double > &	c,
		double &	dist,
		double &	u,
		double &	v
	)

Find the closest point on the triangle a,b,c to point p.

Returns:: a code same as other version of this function

Parameters:

dist	is the distance to the triangle (returned by reference)
u	and
v	are the barycentric coordinates of the closest point

Definition at line 284 of file imesh_intersect.cxx.

vgl_point_3d<double> imesh_triangle_closest_point	(	const vgl_point_3d< double > &	p,
		const vgl_point_3d< double > &	a,
		const vgl_point_3d< double > &	b,
		const vgl_point_3d< double > &	c,
		double &	dist
	)

Find the closest point on the triangle a,b,c to point p.

Parameters:

dist	is the distance to the triangle (returned by reference)

Definition at line 299 of file imesh_intersect.cxx.

unsigned char imesh_triangle_intersect	(	const vgl_point_2d< double > &	p,
		const vgl_vector_2d< double > &	d,
		const vgl_point_2d< double > &	a,
		const vgl_point_2d< double > &	b,
		const vgl_point_2d< double > &	c,
		double &	u,
		double &	v
	)

Find the closest intersection point from p along d with triangle a,b,c.

Returns:

a code indicating that the intersection point:

0 does not exist
1 is a
2 is b
3 is on the edge from a to b
4 is c
5 is on the edge from a to c
6 is on the edge from b to c
7 could not be computed (error)

Parameters:

u	and
v	are the barycentric coordinates of the intersection

Definition at line 362 of file imesh_intersect.cxx.

unsigned char imesh_triangle_intersect	(	double &	u,
		double &	v,
		const double &	du,
		const double &	dv,
		const double &	eps
	)

Find the closest intersection point along the vector (du,dv).

Both the vector (du,dv) and the intersection point are in barycentric coordinates

Returns:

a code indicating that the intersection point:

0 does not exist
1 is at corner (0,0)
2 is at corner (1,0)
3 is on the edge v=0
4 is at corner (0,1)
5 is on the edge from u=0
6 is on the edge from u+v=1
7 could not be computed (error)

Parameters:

u	and
v	are updated to the coordinates of the intersection

Find the closest intersection point along the vector (du,dv).

Returns:

a code indicating that the intersection point:

0 does not exist
1 is at corner (0,0)
2 is at corner (1,0)
3 is on the edge v=0
4 is at corner (0,1)
5 is on the edge from u=0
6 is on the edge from u+v=1
7 could not be computed (error)

Parameters:

u	and
v	are updated to the coordinates of the intersection

Definition at line 396 of file imesh_intersect.cxx.