Mesh processing algorithms related to cleaning of the mesh. More...

Detailed Description

Mesh processing algorithms related to cleaning of the mesh.

Classes
struct	ImFusionOriginProperty
	Vertex and / or face property indicating the origin of a vertex or face in the mesh, added to the mesh by cropMesh. More...

Enumerations
enum class	CropType { InfrontUnion , InfrontIntersection , BehindUnion , BehindIntersection }
	CropType for cropMesh method. More...

Functions
void	mergeCloseVertices (Mesh &mesh, double delta=0.0, bool allowFaceReordering=false)
	Remove close mesh vertices.
void	removeIsolatedVertices (Mesh &mesh)
	Remove vertices not belonging to any face.
void	crop (Mesh &mesh, const vec3 &boxCenter, const vec3 &boxExtent, const bool discardPointsInside, const mat4 &transformation, bool cap=false, Progress *progress=nullptr)
	Deletes all faces that are not inside the given box.
void	crop (Mesh &mesh, const std::vector< Geometry::Plane > &planes, CropType cropType, bool cap=false, Progress *progress=nullptr)
	Crops a mesh using a set of planes.

Enumeration Type Documentation

◆ CropType

enum class ImFusion::MeshProcessing::Cleaning::CropType

strong

CropType for cropMesh method.

Defines the desired output of the mesh cropping, i.e. which. parts of the mesh are to be kept after cropping.

Enumerator
InfrontUnion	The union of the regions on the normal side of the planes.
InfrontIntersection	The intersection of the regions on the normal side of the planes.
BehindUnion	The union of the regions on the opposite side of the planes normal.
BehindIntersection	The intersection of the regions on the opposite side of the planes normal.

Function Documentation

◆ mergeCloseVertices()

void ImFusion::MeshProcessing::Cleaning::mergeCloseVertices	(	Mesh &	mesh,
		double	delta = 0.0,
		bool	allowFaceReordering = false )

Remove close mesh vertices.

This function merges vertices in a mesh that are closer than delta (using the L2 norm). To do so it builds a graph whose nodes $V = {\mathbf{v}_0,...,\mathbf{v}_n}$ represent the vertices of the mesh and whose edges $E$ contain $e_{i,j} \in E \Leftrightarrow ||v_i-v_j|| < \delta$. Connected components in this graph are subsequentially merged into one representative vertex before faces are reassigned to the new vertices. This means that the total circumference of a merged cluster might exceed delta if there is a long "chain" of vertices which are pairwise closer than delta.

Note: This function keeps properties of unique vertices and faces, but the properties of vertices and faces resulting from a merge are copied from the vertex with maximum index in the cluster and from the face with minimum index, respectively.; For vertex colors, normals, and texture coordinates a respective halfedge property will be added if the properties do not match at any vertex. The vertex property will then be removed.

Warning: Merging vertices might change the topology of the mesh, in particular small holes might be closed in the process.

Parameters

[in,out]	mesh	Mesh
[in]	delta	threshold for the distance between vertices. If distance between vertices is smaller than the threshold, vertices will be merged (optional, default is 0.0)

◆ crop() [1/2]

void ImFusion::MeshProcessing::Cleaning::crop	(	Mesh &	mesh,
		const vec3 &	boxCenter,
		const vec3 &	boxExtent,
		const bool	discardPointsInside,
		const mat4 &	transformation,
		bool	cap = false,
		Progress *	progress = nullptr )

Deletes all faces that are not inside the given box.

Operates directly on the input mesh without making a copy

For a detailed explanation and the handling of properties see

See also: cropMesh(Mesh&, const std::vector<Geometry::Plane>&, CropType, bool, Progress*);

Parameters

[in,out]	mesh	Mesh
[in]	boxCenter	center of the cropping box
[in]	boxExtent	the extent in all axes of the cropping box
[in]	discardPointsInside	should the points inside or outside the box be discarded
[in]	transformation	a transformation that is applied to the cropping box
[in]	cap	(optional) should cap the cropped mesh, default is false
[in]	progress	(optional) a pointer to a progress handler, default is nullptr

◆ crop() [2/2]

void ImFusion::MeshProcessing::Cleaning::crop	(	Mesh &	mesh,
		const std::vector< Geometry::Plane > &	planes,
		CropType	cropType,
		bool	cap = false,
		Progress *	progress = nullptr )

Crops a mesh using a set of planes.

The crop parameter defines the desired output of the mesh cropping. Operates directly on the input mesh without making a copy

Mesh attributes will be handled in the following way:

A vertex property of type ImFusionOriginProperty::element_type is added to the mesh describing the origin of each mesh vertex in the result, see
See also
ImFusionOriginProperty for an explanation
Normal, color, and texture coordinate vertex properties are linear interpolated on the intersection curves between planes and mesh
Other vertex properties on the intersection curves and vertex properties in the filled regions (if cap` == true) are undefined (except normals, see below).
If \a mesh has the vertex normal property the vertex normals in the filled regions are computed. Additionally the halfedge normal property is added and set accordingly to support shading the sharp cropping edges.
If \a mesh has vertex color or texture coordinate properties the respective halfedge properties are added and set.
If \a mesh has the face normal property all face normals are recomputed.
All other existing vertex, face, edge, and halfedge properties are kept at vertices and faces with ImFusionOriginProperty::Original property, at other vertices and faces they are undefined. \note If the mesh is not watertight and the cropping planes cross some boundary, the resulting hole will only be filled between the newly created vertices, i.e. vertices on the planes \param [in,out] mesh Mesh \param [in] planes the cropping planes \param [in] cropType type of cropping \param [in] cap (optional) should the cropped mesh be capped. Default is false. \param [in] progress (optional) a pointer to a progress handler. Default is nullptr`.