trimesh.base module¶
github.com/mikedh/trimesh¶
Library for importing, exporting and doing simple operations on triangular meshes.
Classes


class
trimesh.base.
Trimesh
(vertices=None, faces=None, face_normals=None, vertex_normals=None, face_colors=None, vertex_colors=None, face_attributes=None, vertex_attributes=None, metadata=None, process=True, validate=False, use_embree=True, initial_cache=None, visual=None, **kwargs)¶ Bases:
trimesh.parent.Geometry
Methods
apply_transform
(matrix)Transform mesh by a homogeneous transformation matrix.
compute_stable_poses
([center_mass, sigma, …])Computes stable orientations of a mesh and their quasistatic probabilites.
contains
(points)Given an array of points determine whether or not they are inside the mesh.
convert_units
(desired[, guess])Convert the units of the mesh into a specified unit.
convex_decomposition
([maxhulls])Compute an approximate convex decomposition of a mesh.
copy
([include_cache])Safely return a copy of the current mesh.
crc
()A zlib.adler32 checksum for the current mesh data.
difference
(other[, engine])Boolean difference between this mesh and n other meshes
eval_cached
(statement, *args)Evaluate a statement and cache the result before returning.
export
([file_obj, file_type])Export the current mesh to a file object.
Fill single triangle and single quad holes in the current mesh.
fix_normals
(**kwargs)Find and fix problems with self.face_normals and self.faces winding direction.
intersection
(other[, engine])Boolean intersection between this mesh and n other meshes
invert
()Invert the mesh inplace by reversing the winding of every face and negating normals without dumping the cache.
md5
()An MD5 of the core geometry information for the mesh, faces and vertices.
merge_vertices
(**kwargs)If a mesh has vertices that are closer than trimesh.constants.tol.merge reindex faces to reference the same index for both vertices.
outline
([face_ids])Given a list of face indexes find the outline of those faces and return it as a Path3D.
process
(**kwargs)Do the bare minimum processing to make a mesh useful.
register
(other, **kwargs)Align a mesh with another mesh or a PointCloud using the principal axes of inertia as a starting point which is refined by iterative closest point.
remove_degenerate_faces
([height])Remove degenerate faces (faces without 3 unique vertex indices) from the current mesh.
On the current mesh remove any faces which are duplicates.
Ensure that every vertex and face consists of finite numbers.
Remove all vertices in the current mesh which are not referenced by a face.
rezero
()Translate the mesh so that all vertex vertices are positive.
sample
(count[, return_index])Return random samples distributed across the
scene
(**kwargs)Returns a Scene object containing the current mesh.
section
(plane_normal, plane_origin)Returns a 3D cross section of the current mesh and a plane defined by origin and normal.
section_multiplane
(plane_origin, …)Return multiple parallel cross sections of the current mesh in 2D.
show
(**kwargs)Render the mesh in an opengl window.
slice_plane
(plane_origin, plane_normal, **kwargs)Slice the mesh with a plane, returning a new mesh that is the
smoothed
(**kwargs)Return a version of the current mesh which will render nicely, without changing source mesh.
split
(**kwargs)Returns a list of Trimesh objects, based on face connectivity.
subdivide
([face_index])Subdivide a mesh, with each subdivided face replaced with four smaller faces.
submesh
(faces_sequence, **kwargs)Return a subset of the mesh.
to_dict
()Return a dictionary representation of the current mesh, with keys
union
(other[, engine])Boolean union between this mesh and n other meshes
Removes all face references so that every face contains three unique vertex indices and no faces are adjacent.
update_faces
(mask)In many cases, we will want to remove specific faces.
update_vertices
(mask[, inverse])Update vertices with a mask.
voxelized
(pitch[, method])Return a VoxelGrid object representing the current mesh
Attributes
Summed area of all triangles in the current mesh.
The area of each face in the mesh.
How many connected groups of vertices exist in this mesh.
The axis aligned bounds of the faces of the mesh.
The point in space which is the center of mass/volume.
The point in space which is the average of the triangle centroids weighted by the area of each triangle.
Returns a Trimesh object representing the convex hull of the current mesh.
The density of the mesh.
Edges of the mesh (derived from faces).
Which face does each edge belong to.
Edges sorted along axis 1
A KDTree for mapping edges back to edge index.
Edges in sparse bool COO graph format where connected vertices are True.
The unique edges of the mesh.
Return the inverse required to reproduce self.edges_sorted from self.edges_unique.
How long is each unique edge.
Return the Euler characteristic (a topological invariant) for the mesh
The length, width, and height of the axis aligned bounding box of the mesh.
Find faces that share an edge, which we call here ‘adjacent’.
Return the angle between adjacent faces
Return faces which are adjacent and locally convex.
Returns the edges that are shared by the adjacent faces.
A KDTree for mapping edges back face adjacency index.
The projection of the nonshared vertex of a triangle onto
The approximate radius of a cylinder that fits inside adjacent faces.
The approximate perpendicular projection of the nonshared vertices in a pair of adjacent faces onto the shared edge of the two faces.
An Rtree of face adjacencies.
Return the vertex index of the two vertices not in the shared
Returns the angle at each vertex of a face.
A sparse matrix representation of the face angles.
Return the unit normal vector for each face.
The faces of the mesh.
A sparse matrix representation of the faces.
For each face return which indexes in mesh.unique_edges constructs that face.
Return a list of face indices for coplanar adjacent faces.
Return an array containing the area of each facet.
Return the edges which represent the boundary of each facet
Return the normal of each facet
Find which facets of the mesh are on the convex hull.
Return a point on the facet plane.
Return a float vector which is unique to the mesh and is robust to rotation and translation.
An MD5 of the rotation invariant identifier vector
Check if a mesh is convex or not.
Does the current mesh have data defined.
Check if a mesh has all the properties required to represent a valid volume, rather than just a surface.
Check if a mesh is watertight by making sure every edge is included in two faces.
Does the mesh have consistent winding or not.
Return a scipy.spatial.cKDTree of the vertices of the mesh.
Mass of the current mesh, based on specified density and volume.
Returns the mass properties of the current mesh.
Return the moment of inertia matrix of the current mesh.
Return the principal components of inertia
A transform which moves the current mesh so the principal inertia vectors are on the X,Y, and Z axis, and the centroid is at the origin.
Return the principal axis of inertia.
Which vertices in the current mesh are referenced by a face.
A metric for the overall scale of the mesh, the length of the diagonal of the axis aligned bounding box of the mesh.
Check whether a mesh has rotational symmetry.
If a mesh has rotational symmetry, return the axis.
If a mesh has rotational symmetry, return the two vectors which make up a section coordinate frame.
Actual triangles of the mesh (points, not indexes)
The center of each triangle (barycentric [1/3, 1/3, 1/3])
The cross product of two edges of each triangle.
An Rtree containing each face of the mesh.
Definition of units for the mesh.
Returns a networkx graph representing the vertices and their connections in the mesh.
Return the vertex defects, or (2*pi) minus the sum of the angles of every face that includes that vertex.
Return the number of faces each vertex is included in.
A representation of the face indices that correspond to each vertex.
The vertex neighbors of each vertex of the mesh, determined from the cached vertex_adjacency_graph, if already existent.
The vertex normals of the mesh.
The vertices of the mesh.
Get the stored visuals for the current mesh.
Volume of the current mesh calculated using a surface integral.

apply_transform
(matrix)¶ Transform mesh by a homogeneous transformation matrix.
Does the bookkeeping to avoid recomputing things so this function should be used rather than directly modifying self.vertices if possible.
 Parameters
matrix ((4, 4) float) – Homogeneous transformation matrix

property
area
¶ Summed area of all triangles in the current mesh.
 Returns
area – Surface area of mesh
 Return type
float

property
area_faces
¶ The area of each face in the mesh.
 Returns
area_faces – Area of each face
 Return type
(n, ) float

property
body_count
¶ How many connected groups of vertices exist in this mesh.
Note that this number may differ from result in mesh.split, which is calculated from FACE rather than vertex adjacency.
 Returns
count – Number of connected vertex groups
 Return type
int

property
bounds
¶ The axis aligned bounds of the faces of the mesh.
 Returns
bounds – Bounding box with [min, max] coordinates If mesh is empty will return None
 Return type
(2, 3) float or None

property
center_mass
¶ The point in space which is the center of mass/volume.
If the current mesh is not watertight this is meaningless garbage unless it was explicitly set.
 Returns
center_mass – Volumetric center of mass of the mesh
 Return type
(3, ) float

property
centroid
¶ The point in space which is the average of the triangle centroids weighted by the area of each triangle.
This will be valid even for nonwatertight meshes, unlike self.center_mass
 Returns
centroid – The average vertex weighted by face area
 Return type
(3, ) float

compute_stable_poses
(center_mass=None, sigma=0.0, n_samples=1, threshold=0.0)¶ Computes stable orientations of a mesh and their quasistatic probabilites.
This method samples the location of the center of mass from a multivariate gaussian (mean at com, cov equal to identity times sigma) over n_samples. For each sample, it computes the stable resting poses of the mesh on a a planar workspace and evaluates the probabilities of landing in each pose if the object is dropped onto the table randomly.
This method returns the 4x4 homogeneous transform matrices that place the shape against the planar surface with the zaxis pointing upwards and a list of the probabilities for each pose. The transforms and probabilties that are returned are sorted, with the most probable pose first.
 Parameters
center_mass ((3, ) float) – The object center of mass (if None, this method assumes uniform density and watertightness and computes a center of mass explicitly)
sigma (float) – The covariance for the multivariate gaussian used to sample center of mass locations
n_samples (int) – The number of samples of the center of mass location
threshold (float) – The probability value at which to threshold returned stable poses
 Returns
transforms ((n, 4, 4) float) – The homogeneous matrices that transform the object to rest in a stable pose, with the new zaxis pointing upwards from the table and the object just touching the table.
probs ((n, ) float) – A probability ranging from 0.0 to 1.0 for each pose

contains
(points)¶ Given an array of points determine whether or not they are inside the mesh. This raises an error if called on a nonwatertight mesh.
 Parameters
points ((n, 3) float) – Points in cartesian space
 Returns
contains – Whether or not each point is inside the mesh
 Return type
(n, ) bool

convert_units
(desired, guess=False)¶ Convert the units of the mesh into a specified unit.
 Parameters
desired (string) – Units to convert to (eg ‘inches’)
guess (boolean) – If self.units are not defined should we guess the current units of the document and then convert?

convex_decomposition
(maxhulls=20, **kwargs)¶ Compute an approximate convex decomposition of a mesh.
testVHACD Parameters which can be passed as kwargs:
resolution 100000 max. concavity 0.001 plane downsampling 4 convexhull downsampling 4 alpha 0.05 beta 0.05 maxhulls 10 pca 0 mode 0 max. vertices per convexhull 64 min. volume to add vertices to convexhulls 0.0001 convexhull approximation 1 OpenCL acceleration 1 OpenCL platform ID 0 OpenCL device ID 0 output output.wrl log log.txt
 Parameters
maxhulls (int) – Maximum number of convex hulls to return
**kwargs (testVHACD keyword arguments) –
 Returns
meshes – List of convex meshes that approximate the original
 Return type
list of trimesh.Trimesh

property
convex_hull
¶ Returns a Trimesh object representing the convex hull of the current mesh.
 Returns
convex – Mesh of convex hull of current mesh
 Return type

copy
(include_cache=False)¶ Safely return a copy of the current mesh.
By default, copied meshes will have emptied cache to avoid memory issues and so may be slow on initial operations until caches are regenerated.
Current object will never have its cache cleared.
 Parameters
include_cache (bool) – If True, will shallow copy cached data to new mesh
 Returns
copied – Copy of current mesh
 Return type

crc
()¶ A zlib.adler32 checksum for the current mesh data.
This is about 5x faster than an MD5, and the checksum is checked every time something is requested from the cache so it gets called a lot.
 Returns
crc – Checksum of current mesh data
 Return type
int

property
density
¶ The density of the mesh.
 Returns
density – The density of the mesh.
 Return type
float

difference
(other, engine=None, **kwargs)¶ Boolean difference between this mesh and n other meshes
 Parameters
other (trimesh.Trimesh, or list of trimesh.Trimesh objects) – Meshes to difference
 Returns
difference – Difference between self and other Trimesh objects
 Return type

property
edges
¶ Edges of the mesh (derived from faces).
 Returns
edges – List of vertex indices making up edges
 Return type
(n, 2) int

property
edges_face
¶ Which face does each edge belong to.
 Returns
edges_face – Index of self.faces
 Return type
(n, ) int

property
edges_sorted
¶ Edges sorted along axis 1
 Returns
edges_sorted – Same as self.edges but sorted along axis 1
 Return type
(n, 2)

property
edges_sorted_tree
¶ A KDTree for mapping edges back to edge index.
 Returns
tree – Tree when queried with edges will return their index in mesh.edges_sorted
 Return type
scipy.spatial.cKDTree

property
edges_sparse
¶ Edges in sparse bool COO graph format where connected vertices are True.
 Returns
sparse – Sparse graph in COO format
 Return type
(len(self.vertices), len(self.vertices)) bool

property
edges_unique
¶ The unique edges of the mesh.
 Returns
edges_unique – Vertex indices for unique edges
 Return type
(n, 2) int

property
edges_unique_inverse
¶ Return the inverse required to reproduce self.edges_sorted from self.edges_unique.
Useful for referencing edge properties: mesh.edges_unique[mesh.edges_unique_inverse] == m.edges_sorted
 Returns
inverse – Indexes of self.edges_unique
 Return type
(len(self.edges), ) int

property
edges_unique_length
¶ How long is each unique edge.
 Returns
length – Length of each unique edge
 Return type
(len(self.edges_unique), ) float

property
euler_number
¶ Return the Euler characteristic (a topological invariant) for the mesh In order to guarantee correctness, this should be called after remove_unreferenced_vertices
 Returns
euler_number – Topological invariant
 Return type
int

eval_cached
(statement, *args)¶ Evaluate a statement and cache the result before returning.
Statements are evaluated inside the Trimesh object, and
 Parameters
statement (str) – Statement of valid python code
*args (list) – Available inside statement as args[0], etc
 Returns
result
 Return type
result of running eval on statement with args
Examples
r = mesh.eval_cached(‘np.dot(self.vertices, args[0])’, [0, 0, 1])

export
(file_obj=None, file_type=None, **kwargs)¶ Export the current mesh to a file object. If file_obj is a filename, file will be written there.
Supported formats are stl, off, ply, collada, json, dict, glb, dict64, msgpack.
 Parameters
file_obj (open writeable file object) – str, file name where to save the mesh None, if you would like this function to return the export blob
file_type (str) – Which file type to export as. If file name is passed this is not required

property
extents
¶ The length, width, and height of the axis aligned bounding box of the mesh.
 Returns
extents – Array containing axis aligned [length, width, height] If mesh is empty returns None
 Return type
(3, ) float or None

property
face_adjacency
¶ Find faces that share an edge, which we call here ‘adjacent’.
 Returns
adjacency – Pairs of faces which share an edge
 Return type
(n, 2) int
Examples
In [1]: mesh = trimesh.load(‘models/featuretype.STL’)
In [2]: mesh.face_adjacency Out[2]: array([[ 0, 1],
[ 2, 3], [ 0, 3], …, [1112, 949], [3467, 3475], [1113, 3475]])
In [3]: mesh.faces[mesh.face_adjacency[0]] Out[3]: TrackedArray([[ 1, 0, 408],
[1239, 0, 1]], dtype=int64)
In [4]: import networkx as nx
In [5]: graph = nx.from_edgelist(mesh.face_adjacency)
In [6]: groups = nx.connected_components(graph)

property
face_adjacency_angles
¶ Return the angle between adjacent faces
 Returns
adjacency_angle – Angle between adjacent faces Each value corresponds with self.face_adjacency
 Return type
(n, ) float

property
face_adjacency_convex
¶ Return faces which are adjacent and locally convex.
What this means is that given faces A and B, the one vertex in B that is not shared with A, projected onto the plane of A has a projection that is zero or negative.
 Returns
are_convex – Face pairs that are locally convex
 Return type
(len(self.face_adjacency), ) bool

property
face_adjacency_edges
¶ Returns the edges that are shared by the adjacent faces.
 Returns
edges – Vertex indices which correspond to face_adjacency
 Return type
(n, 2) int

property
face_adjacency_edges_tree
¶ A KDTree for mapping edges back face adjacency index.
 Returns
tree – Tree when queried with SORTED edges will return their index in mesh.face_adjacency
 Return type
scipy.spatial.cKDTree

property
face_adjacency_projections
¶ The projection of the nonshared vertex of a triangle onto its adjacent face
 Returns
projections – Dot product of vertex onto plane of adjacent triangle.
 Return type
(len(self.face_adjacency), ) float

property
face_adjacency_radius
¶ The approximate radius of a cylinder that fits inside adjacent faces.
 Returns
radii – Approximate radius formed by triangle pair
 Return type
(len(self.face_adjacency), ) float

property
face_adjacency_span
¶ The approximate perpendicular projection of the nonshared vertices in a pair of adjacent faces onto the shared edge of the two faces.
 Returns
span – Approximate span between the nonshared vertices
 Return type
(len(self.face_adjacency), ) float

property
face_adjacency_tree
¶ An Rtree of face adjacencies.
 Returns
tree – Where each edge in self.face_adjacency has a rectangular cell
 Return type
rtree.index
Return the vertex index of the two vertices not in the shared edge between two adjacent faces
 Returns
vid_unshared – Indexes of mesh.vertices
 Return type
(len(mesh.face_adjacency), 2) int

property
face_angles
¶ Returns the angle at each vertex of a face.
 Returns
angles – Angle at each vertex of a face
 Return type
(len(self.faces), 3) float

property
face_angles_sparse
¶ A sparse matrix representation of the face angles.
 Returns
sparse – Float sparse matrix with with shape: (len(self.vertices), len(self.faces))
 Return type
scipy.sparse.coo_matrix

property
face_normals
¶ Return the unit normal vector for each face.
If a face is degenerate and a normal can’t be generated a zero magnitude unit vector will be returned for that face.
 Returns
normals – Normal vectors of each face
 Return type
(len(self.faces), 3) np.float64

property
faces
¶ The faces of the mesh.
This is regarded as core information which cannot be regenerated from cache, and as such is stored in self._data which tracks the array for changes and clears cached values of the mesh if this is altered.
 Returns
faces – Representing triangles which reference self.vertices
 Return type
(n, 3) int

property
faces_sparse
¶ A sparse matrix representation of the faces.
 Returns
sparse – Has properties: dtype : bool shape : (len(self.vertices), len(self.faces))
 Return type
scipy.sparse.coo_matrix

property
faces_unique_edges
¶ For each face return which indexes in mesh.unique_edges constructs that face.
 Returns
faces_unique_edges – Indexes of self.edges_unique that construct self.faces
 Return type
(len(self.faces), 3) int
Examples
In [0]: mesh.faces[0:2] Out[0]: TrackedArray([[ 1, 6946, 24224],
[ 6946, 1727, 24225]])
In [1]: mesh.edges_unique[mesh.faces_unique_edges[0:2]] Out[1]: array([[[ 1, 6946],
[ 6946, 24224], [ 1, 24224]],
 [[ 1727, 6946],
[ 1727, 24225], [ 6946, 24225]]])

property
facets
¶ Return a list of face indices for coplanar adjacent faces.
 Returns
facets – Groups of indexes of self.faces
 Return type
(n, ) sequence of (m, ) int

property
facets_area
¶ Return an array containing the area of each facet.
 Returns
area – Total area of each facet (group of faces)
 Return type
(len(self.facets), ) float

property
facets_boundary
¶ Return the edges which represent the boundary of each facet
 Returns
edges_boundary – Indices of self.vertices
 Return type
sequence of (n, 2) int

property
facets_normal
¶ Return the normal of each facet
 Returns
normals – A unit normal vector for each facet
 Return type
(len(self.facets), 3) float

property
facets_on_hull
¶ Find which facets of the mesh are on the convex hull.
 Returns
on_hull – is A facet on the meshes convex hull or not
 Return type
(len(mesh.facets), ) bool

property
facets_origin
¶ Return a point on the facet plane.
 Returns
origins – A point on each facet plane
 Return type
(len(self.facets), 3) float

fill_holes
()¶ Fill single triangle and single quad holes in the current mesh.
 Returns
watertight – Is the mesh watertight after the function completes
 Return type
bool

fix_normals
(**kwargs)¶ Find and fix problems with self.face_normals and self.faces winding direction.
For face normals ensure that vectors are consistently pointed outwards, and that self.faces is wound in the correct direction for all connected components.
 Parameters
multibody (None or bool) – Fix normals across multiple bodies if None automatically pick from body_count

property
identifier
¶ Return a float vector which is unique to the mesh and is robust to rotation and translation.
 Returns
identifier – Identifying properties of the current mesh
 Return type
(6, ) float

property
identifier_md5
¶ An MD5 of the rotation invariant identifier vector
 Returns
hashed – MD5 hash of the identifier vector
 Return type
str

intersection
(other, engine=None, **kwargs)¶ Boolean intersection between this mesh and n other meshes
 Parameters
other (trimesh.Trimesh, or list of trimesh.Trimesh objects) – Meshes to calculate intersections with
 Returns
intersection – Mesh of the volume contained by all passed meshes
 Return type

invert
()¶ Invert the mesh inplace by reversing the winding of every face and negating normals without dumping the cache.
self.faces : columns reversed self.face_normals : negated if defined self.vertex_normals : negated if defined

property
is_convex
¶ Check if a mesh is convex or not.
 Returns
is_convex – Is mesh convex or not
 Return type
bool

property
is_empty
¶ Does the current mesh have data defined.
 Returns
empty – If True, no data is set on the current mesh
 Return type
bool

property
is_volume
¶ Check if a mesh has all the properties required to represent a valid volume, rather than just a surface.
These properties include being watertight, having consistent winding and outward facing normals.
 Returns
valid – Does the mesh represent a volume
 Return type
bool

property
is_watertight
¶ Check if a mesh is watertight by making sure every edge is included in two faces.
 Returns
is_watertight – Is mesh watertight or not
 Return type
bool

property
is_winding_consistent
¶ Does the mesh have consistent winding or not. A mesh with consistent winding has each shared edge going in an opposite direction from the other in the pair.
 Returns
consistent – Is winding is consistent or not
 Return type
bool

property
kdtree
¶ Return a scipy.spatial.cKDTree of the vertices of the mesh. Not cached as this lead to observed memory issues and segfaults.
 Returns
tree – Contains mesh.vertices
 Return type
scipy.spatial.cKDTree

property
mass
¶ Mass of the current mesh, based on specified density and volume. If the current mesh isn’t watertight this is garbage.
 Returns
mass – Mass of the current mesh
 Return type
float

property
mass_properties
¶ Returns the mass properties of the current mesh.
Assumes uniform density, and result is probably garbage if mesh isn’t watertight.
 Returns
properties – With keys: ‘volume’ : in global units^3 ‘mass’ : From specified density ‘density’ : Included again for convenience (same as kwarg density) ‘inertia’ : Taken at the center of mass and aligned with global
coordinate system
’center_mass’ : Center of mass location, in global coordinate system
 Return type
dict

md5
()¶ An MD5 of the core geometry information for the mesh, faces and vertices.
Generated from TrackedArray which subclasses np.ndarray to monitor array for changes and returns a correct lazily evaluated md5 so it only has to recalculate the hash occasionally, rather than on every call.
 Returns
md5 – MD5 of everything in the DataStore
 Return type
string

merge_vertices
(**kwargs)¶ If a mesh has vertices that are closer than trimesh.constants.tol.merge reindex faces to reference the same index for both vertices.
 Parameters
mesh (Trimesh object) – Mesh to merge vertices on
use_tex (bool) – If True for textured meshes merge vertices with identical positions AND UV coordinates.
use_norm (bool) – If True meshes with vertex normals defined will only have vertices merged with identical normal
digits_vertex (None or int) – Number of digits to consider for vertex position
digits_norm (int) – Number of digits to consider for unit normals
digits_uv (int) – Number of digits to consider for UV coordinates

property
moment_inertia
¶ Return the moment of inertia matrix of the current mesh. If mesh isn’t watertight this is garbage.
 Returns
inertia – Moment of inertia of the current mesh
 Return type
(3, 3) float

outline
(face_ids=None, **kwargs)¶ Given a list of face indexes find the outline of those faces and return it as a Path3D.
The outline is defined here as every edge which is only included by a single triangle.
Note that this implies a nonwatertight mesh as the outline of a watertight mesh is an empty path.
 Parameters
face_ids ((n, ) int) – Indices to compute the outline of. If None, outline of full mesh will be computed.
**kwargs (passed to Path3D constructor) –
 Returns
path – Curve in 3D of the outline
 Return type

property
principal_inertia_components
¶ Return the principal components of inertia
Ordering corresponds to mesh.principal_inertia_vectors
 Returns
components – Principal components of inertia
 Return type
(3, ) float

property
principal_inertia_transform
¶ A transform which moves the current mesh so the principal inertia vectors are on the X,Y, and Z axis, and the centroid is at the origin.
 Returns
transform – Homogeneous transformation matrix
 Return type
(4, 4) float

property
principal_inertia_vectors
¶ Return the principal axis of inertia.
Ordering corresponds to mesh.principal_inertia_components
 Returns
vectors – Three vectors pointing along the principal axis of inertia directions
 Return type
(3, 3) float

process
(**kwargs)¶ Do the bare minimum processing to make a mesh useful.
 Does this by:
removing NaN and Inf values
merging duplicate vertices
 If self._validate:
Remove triangles which have one edge of their rectangular 2D oriented bounding box shorter than tol.merge
remove duplicated triangles
 Returns
self – Current mesh
 Return type

property
referenced_vertices
¶ Which vertices in the current mesh are referenced by a face.
 Returns
referenced – Which vertices are referenced by a face
 Return type
(len(self.vertices), ) bool

register
(other, **kwargs)¶ Align a mesh with another mesh or a PointCloud using the principal axes of inertia as a starting point which is refined by iterative closest point.
 Parameters
mesh (trimesh.Trimesh object) – Mesh to align with other
other (trimesh.Trimesh or (n, 3) float) – Mesh or points in space
samples (int) – Number of samples from mesh surface to align
icp_first (int) – How many ICP iterations for the 9 possible combinations of
icp_final (int) – How many ICP itertations for the closest candidate from the wider search
 Returns
mesh_to_other ((4, 4) float) – Transform to align mesh to the other object
cost (float) – Average square distance per point

remove_degenerate_faces
(height=1e08)¶ Remove degenerate faces (faces without 3 unique vertex indices) from the current mesh.
If a height is specified, it will remove any face with a 2D oriented bounding box with one edge shorter than that height.
If not specified, it will remove any face with a zero normal.
 Parameters
height (float) – If specified removes faces with an oriented bounding box shorter than this on one side.
 Returns
nondegenerate – Mask used to remove faces
 Return type
(len(self.faces), ) bool

remove_duplicate_faces
()¶ On the current mesh remove any faces which are duplicates.
self.faces : removes duplicates

remove_infinite_values
()¶ Ensure that every vertex and face consists of finite numbers.
This will remove vertices or faces containing np.nan and np.inf
self.faces : masked to remove np.inf/np.nan self.vertices : masked to remove np.inf/np.nan

remove_unreferenced_vertices
()¶ Remove all vertices in the current mesh which are not referenced by a face.

rezero
()¶ Translate the mesh so that all vertex vertices are positive.
self.vertices : Translated to first octant (all values > 0)

sample
(count, return_index=False)¶ Return random samples distributed across the surface of the mesh
 Parameters
count (int) – Number of points to sample
return_index (bool) – If True will also return the index of which face each sample was taken from.
 Returns
samples ((count, 3) float) – Points on surface of mesh
face_index ((count, ) int) – Index of self.faces

property
scale
¶ A metric for the overall scale of the mesh, the length of the diagonal of the axis aligned bounding box of the mesh.
 Returns
scale – The length of the meshes AABB diagonal
 Return type
float

scene
(**kwargs)¶ Returns a Scene object containing the current mesh.
 Returns
scene – Contains just the current mesh
 Return type

section
(plane_normal, plane_origin)¶ Returns a 3D cross section of the current mesh and a plane defined by origin and normal.
 Parameters
plane_normal – Normal vector of section plane
plane_origin ((3, ) float) – Point on the cross section plane
 Returns
intersections – Curve of intersection
 Return type
Path3D or None

section_multiplane
(plane_origin, plane_normal, heights)¶ Return multiple parallel cross sections of the current mesh in 2D.
 Parameters
plane_normal – Normal vector of section plane
plane_origin ((3, ) float) – Point on the cross section plane
heights ((n, ) float) – Each section is offset by height along the plane normal.
 Returns
paths – 2D cross sections at specified heights. path.metadata[‘to_3D’] contains transform to return 2D section back into 3D space.
 Return type
(n, ) Path2D or None

show
(**kwargs)¶ Render the mesh in an opengl window. Requires pyglet.
 Parameters
smooth (bool) – Run smooth shading on mesh or not, large meshes will be slow
 Returns
scene – Scene with current mesh in it
 Return type
trimesh.scene.Scene

slice_plane
(plane_origin, plane_normal, **kwargs)¶ Slice the mesh with a plane, returning a new mesh that is the portion of the original mesh to the positive normal side of the plane
 Parameters
plane_normal – Normal vector of slicing plane
plane_origin ((3, ) float) – Point on the slicing plane
 Returns
new_mesh – Subset of current mesh that intersects the half plane to the positive normal side of the plane
 Return type
trimesh.Trimesh or None

smoothed
(**kwargs)¶ Return a version of the current mesh which will render nicely, without changing source mesh.
 Parameters
angle (float or None) – Angle in radians face pairs with angles smaller than this will appear smoothed
facet_minarea (float or None) – Minimum area fraction to consider IE for facets_minarea=25 only facets larger than mesh.area / 25 will be considered.
 Returns
smoothed – Non watertight version of current mesh which will render nicely with smooth shading
 Return type

split
(**kwargs)¶ Returns a list of Trimesh objects, based on face connectivity. Splits into individual components, sometimes referred to as ‘bodies’
 Parameters
only_watertight (bool) – Only return watertight meshes and discard remainder
adjacency (None or (n, 2) int) – Override face adjacency with custom values
 Returns
meshes – Separate bodies from original mesh
 Return type
(n, ) trimesh.Trimesh

subdivide
(face_index=None)¶ Subdivide a mesh, with each subdivided face replaced with four smaller faces.
 Parameters
face_index ((m, ) int or None) – If None all faces of mesh will be subdivided If (m, ) int array of indices: only specified faces will be subdivided. Note that in this case the mesh will generally no longer be manifold, as the additional vertex on the midpoint will not be used by the adjacent faces to the faces specified, and an additional postprocessing step will be required to make resulting mesh watertight

submesh
(faces_sequence, **kwargs)¶ Return a subset of the mesh.
 Parameters
faces_sequence (sequence (m, ) int) – Face indices of mesh
only_watertight (bool) – Only return submeshes which are watertight
append (bool) – Return a single mesh which has the faces appended. if this flag is set, only_watertight is ignored
 Returns
if append (trimesh.Trimesh object)
else (list of trimesh.Trimesh objects)

property
symmetry
¶ Check whether a mesh has rotational symmetry.
 Returns
symmetry – ‘radial’ Symmetric around an axis ‘spherical’ Symmetric around a point
 Return type
None No rotational symmetry

property
symmetry_axis
¶ If a mesh has rotational symmetry, return the axis.
 Returns
axis – Axis around which a 2D profile was revolved to generate this mesh
 Return type
(3, ) float

property
symmetry_section
¶ If a mesh has rotational symmetry, return the two vectors which make up a section coordinate frame.
 Returns
section
 Return type
(2, 3) float, vectors to take a section along

to_dict
()¶ Return a dictionary representation of the current mesh, with keys that can be used as the kwargs for the Trimesh constructor, eg:
a = Trimesh(**other_mesh.to_dict())
 Returns
result – With keys that match trimesh constructor
 Return type
dict

property
triangles
¶ Actual triangles of the mesh (points, not indexes)
 Returns
triangles – Points of triangle vertices
 Return type
(n, 3, 3) float

property
triangles_center
¶ The center of each triangle (barycentric [1/3, 1/3, 1/3])
 Returns
triangles_center – Center of each triangular face
 Return type
(len(self.faces), 3) float

property
triangles_cross
¶ The cross product of two edges of each triangle.
 Returns
crosses – Cross product of each triangle
 Return type
(n, 3) float

property
triangles_tree
¶ An Rtree containing each face of the mesh.
 Returns
tree – Each triangle in self.faces has a rectangular cell
 Return type
rtree.index

union
(other, engine=None, **kwargs)¶ Boolean union between this mesh and n other meshes
 Parameters
 Returns
union – Union of self and other Trimesh objects
 Return type

property
units
¶ Definition of units for the mesh.
 Returns
units – Unit system mesh is in, or None if not defined
 Return type
str

unmerge_vertices
()¶ Removes all face references so that every face contains three unique vertex indices and no faces are adjacent.

update_faces
(mask)¶ In many cases, we will want to remove specific faces. However, there is additional bookkeeping to do this cleanly. This function updates the set of faces with a validity mask, as well as keeping track of normals and colors.
 Parameters
valid – Mask to remove faces

update_vertices
(mask, inverse=None)¶ Update vertices with a mask.
 Parameters
vertex_mask ((len(self.vertices)) bool) – Array of which vertices to keep
inverse ((len(self.vertices)) int) – Array to reconstruct vertex references such as output by np.unique

property
vertex_adjacency_graph
¶ Returns a networkx graph representing the vertices and their connections in the mesh.
 Returns
graph – Graph representing vertices and edges between them where vertices are nodes and edges are edges
 Return type
networkx.Graph
Examples
This is useful for getting nearby vertices for a given vertex, potentially for some simple smoothing techniques.
mesh = trimesh.primitives.Box() graph = mesh.vertex_adjacency_graph graph.neighbors(0) > [1, 2, 3, 4]

property
vertex_defects
¶ Return the vertex defects, or (2*pi) minus the sum of the angles of every face that includes that vertex.
If a vertex is only included by coplanar triangles, this will be zero. For convex regions this is positive, and concave negative.
 Returns
vertex_defect – Vertex defect at the every vertex
 Return type
(len(self.vertices), ) float

property
vertex_degree
¶ Return the number of faces each vertex is included in.
 Returns
degree – Number of faces each vertex is included in
 Return type
(len(self.vertices), ) int

property
vertex_faces
¶ A representation of the face indices that correspond to each vertex.
 Returns
vertex_faces – Each row contains the face indices that correspond to the given vertex, padded with 1 up to the max number of faces corresponding to any one vertex Where n == len(self.vertices), m == max number of faces for a single vertex
 Return type
(n,m) int

property
vertex_neighbors
¶ The vertex neighbors of each vertex of the mesh, determined from the cached vertex_adjacency_graph, if already existent.
 Returns
vertex_neighbors – Represents immediate neighbors of each vertex along the edge of a triangle
 Return type
(len(self.vertices), ) int
Examples
This is useful for getting nearby vertices for a given vertex, potentially for some simple smoothing techniques.
>>> mesh = trimesh.primitives.Box() >>> mesh.vertex_neighbors[0] [1, 2, 3, 4]

property
vertex_normals
¶ The vertex normals of the mesh. If the normals were loaded we check to make sure we have the same number of vertex normals and vertices before returning them. If there are no vertex normals defined or a shape mismatch we calculate the vertex normals from the mean normals of the faces the vertex is used in.
 Returns
vertex_normals – Represents the surface normal at each vertex. Where n == len(self.vertices)
 Return type
(n, 3) float

property
vertices
¶ The vertices of the mesh.
This is regarded as core information which cannot be generated from cache and as such is stored in self._data which tracks the array for changes and clears cached values of the mesh if this is altered.
 Returns
vertices – Points in cartesian space referenced by self.faces
 Return type
(n, 3) float

property
visual
¶ Get the stored visuals for the current mesh.
 Returns
visual – Contains visual information about the mesh
 Return type

property
volume
¶ Volume of the current mesh calculated using a surface integral. If the current mesh isn’t watertight this is garbage.
 Returns
volume – Volume of the current mesh
 Return type
float

voxelized
(pitch, method='subdivide', **kwargs)¶ Return a VoxelGrid object representing the current mesh discretized into voxels at the specified pitch
 Parameters
pitch (float) – The edge length of a single voxel
method (implementation key. See trimesh.voxel.creation.voxelizers) –
**kwargs (additional kwargs passed to the specified implementation.) –
 Returns
voxelized – Representing the current mesh
 Return type
VoxelGrid object
