mesh¶
Submodule to manage polygonal meshes.
Mesh¶

class
vedo.mesh.
Mesh
(inputobj=None, c=None, alpha=1, computeNormals=False)[source]¶ Bases:
vedo.pointcloud.Points
Build an instance of object
Mesh
derived fromPointCloud
.Finally input can be a list of vertices and their connectivity (faces of the polygonal mesh). For point clouds  e.i. no faces  just substitute the faces list with
None
.E.g.: Mesh( [ [[x1,y1,z1],[x2,y2,z2], …], [[0,1,2], [1,2,3], …] ] )
 Parameters

addArcLength
(mesh, name='ArcLength')[source]¶ Given a mesh, add the length of the arc intersecting each point of the line.

addCellArea
(name='Area')[source]¶ Add to this mesh a cell data array containing the areas of the polygonal faces

addCellVertexCount
(name='VertexCount')[source]¶ Add to this mesh a cell data array containing the nr of vertices that a polygonal face has.

addConnectivity
()[source]¶ Flag a mesh by connectivity: each disconnected region will receive a different Id. You can access the array of ids through
mesh.getPointArray("RegionId")
.

addCurvatureScalars
(method=0)[source]¶ Add scalars to
Mesh
that contains the curvature calculated in three different ways. Parameters
method (int) – 0gaussian, 1mean, 2max, 3min curvature.
lut – optional vtkLookUpTable up table.
 Example
from vedo import Torus Torus().addCurvatureScalars().addScalarBar().show(axes=1)

addElevationScalars
(lowPoint=(0, 0, 0), highPoint=(0, 0, 1), vrange=(0, 1))[source]¶ Add to
Mesh
a scalar array that contains distance along a specified direction. Parameters
 Example
from vedo import Sphere s = Sphere().addElevationScalars(lowPoint=(0,0,0), highPoint=(1,1,1)) s.addScalarBar().show(axes=1) elevation

addQuality
(measure=6)[source]¶ Calculate functions of quality for the elements of a triangular mesh. This method adds to the mesh a cell array named “Quality”. See class vtkMeshQuality for explanation.
 Parameters
measure (int) –
type of estimator
EDGE RATIO, 0
ASPECT RATIO, 1
RADIUS RATIO, 2
ASPECT FROBENIUS, 3
MED ASPECT FROBENIUS, 4
MAX ASPECT FROBENIUS, 5
MIN_ANGLE, 6
COLLAPSE RATIO, 7
MAX ANGLE, 8
CONDITION, 9
SCALED JACOBIAN, 10
SHEAR, 11
RELATIVE SIZE SQUARED, 12
SHAPE, 13
SHAPE AND SIZE, 14
DISTORTION, 15
MAX EDGE RATIO, 16
SKEW, 17
TAPER, 18
VOLUME, 19
STRETCH, 20
DIAGONAL, 21
DIMENSION, 22
ODDY, 23
SHEAR AND SIZE, 24
JACOBIAN, 25
WARPAGE, 26
ASPECT GAMMA, 27
AREA, 28
ASPECT BETA, 29

addShadow
(x=None, y=None, z=None, c=(0.6, 0.6, 0.6), alpha=1, culling=1)[source]¶ Generate a shadow out of an
Mesh
on one of the three Cartesian planes. The output is a newMesh
representing the shadow. This new mesh is accessible through mesh.shadow. By default the shadow mesh is placed on the bottom wall of the bounding box. Parameters

backFaceCulling
(value=True)[source]¶ Set culling of polygons based on orientation of normal with respect to camera.

boolean
(operation, mesh2)[source]¶ Volumetric union, intersection and subtraction of surfaces.
 Parameters
operation (str) – allowed operations:
'plus'
,'intersect'
,'minus'
.

boundaries
(boundaryEdges=True, nonManifoldEdges=False, featureAngle=180, returnPointIds=False, returnCellIds=False)[source]¶ Return a
Mesh
that shows the boundary lines of an input mesh. Parameters
boundaryEdges (bool) – Turn on/off the extraction of boundary edges.
nonManifoldEdges (bool) – Turn on/off the extraction of nonmanifold edges.
featureAngle (float) – Specify the min angle btw 2 faces for extracting edges.
returnPointIds (bool) – return a numpy array of point indices
returnCellIds (bool) – return a numpy array of cell indices

computeNormals
(points=True, cells=True, featureAngle=None, consistency=True)[source]¶ Compute cell and vertex normals for the mesh.
 Parameters
points (bool) – do the computation for the vertices
cells (bool) – do the computation for the cells
featureAngle (float) – specify the angle that defines a sharp edge. If the difference in angle across neighboring polygons is greater than this value, the shared edge is considered “sharp” and it is splitted.
consistency (bool) – turn on/off the enforcement of consistent polygon ordering.
Warning
if featureAngle is set to a float the Mesh can be modified, and it can have a different nr. of vertices from the original.

connectedCells
(index, returnIds=False)[source]¶ Find all cellls connected to an input vertex specified by its index.

connectedVertices
(index, returnIds=False)[source]¶ Find all vertices connected to an input vertex specified by its index.
 Parameters
returnIds (bool) – return vertex IDs instead of vertex coordinates.

crop
(top=None, bottom=None, right=None, left=None, front=None, back=None, bounds=None)[source]¶ Crop an
Mesh
object. Parameters
top (float) – fraction to crop from the top plane (positive z)
bottom (float) – fraction to crop from the bottom plane (negative z)
front (float) – fraction to crop from the front plane (positive y)
back (float) – fraction to crop from the back plane (negative y)
right (float) – fraction to crop from the right plane (positive x)
left (float) – fraction to crop from the left plane (negative x)
bounds (list) – direct list of bounds passed as [x0,x1, y0,y1, z0,z1]
Example
from vedo import Sphere Sphere().crop(right=0.3, left=0.1).show()

cutWithPointLoop
(points, invert=False, on='points', includeBoundary=False)[source]¶ Cut an
Mesh
object with a set of points forming a closed loop.

decimate
(fraction=0.5, N=None, method='quadric', boundaries=False)[source]¶ Downsample the number of vertices in a mesh to fraction.
 Parameters
fraction (float) – the desired target of reduction.
N (int) – the desired number of final points (fraction is recalculated based on it).
method (str) – can be either ‘quadric’ or ‘pro’. In the first case triagulation will look like more regular, irrespective of the mesh origianl curvature. In the second case triangles are more irregular but mesh is more precise on more curved regions.
boundaries (bool) – (True), in pro mode decide whether to leave boundaries untouched or not.
Note
Setting
fraction=0.1
leaves 10% of the original nr of vertices.

distanceToMesh
(mesh, signed=False, negate=False)[source]¶ Computes the (signed) distance from one mesh to another.

extractLargestRegion
()[source]¶ Extract the largest connected part of a mesh and discard all the smaller pieces.
Hint

extrude
(zshift=1, rotation=0, dR=0, cap=True, res=1)[source]¶ Sweep a polygonal data creating a “skirt” from free edges and lines, and lines from vertices. The input dataset is swept around the zaxis to create new polygonal primitives. For example, sweeping a line results in a cylindrical shell, and sweeping a circle creates a torus.
You can control whether the sweep of a 2D object (i.e., polygon or triangle strip) is capped with the generating geometry. Also, you can control the angle of rotation, and whether translation along the zaxis is performed along with the rotation. (Translation is useful for creating “springs”). You also can adjust the radius of the generating geometry using the “dR” keyword.
The skirt is generated by locating certain topological features. Free edges (edges of polygons or triangle strips only used by one polygon or triangle strips) generate surfaces. This is true also of lines or polylines. Vertices generate lines.
This filter can be used to model axisymmetric objects like cylinders, bottles, and wine glasses; or translational/rotational symmetric objects like springs or corkscrews.
Warning
Some polygonal objects have no free edges (e.g., sphere). When swept, this will result in two separate surfaces if capping is on, or no surface if capping is off.

faces
()[source]¶ Get cell polygonal connectivity ids as a python
list
. The output format is: [[id0 … idn], [id0 … idm], etc].

fillHoles
(size=None)[source]¶ Identifies and fills holes in input mesh. Holes are identified by locating boundary edges, linking them together into loops, and then triangulating the resulting loops.
 Parameters
size (float) – approximate limit to the size of the hole that can be filled.
Example: fillholes.py

followCamera
(cam=None)[source]¶ Mesh object will follow camera movements and stay locked to it. Use
mesh.followCamera(False)
to disable it. Parameters
cam (vtkCamera) – if None the text will autoorient itself to the active camera. A
vtkCamera
object can also be passed.

frontFaceCulling
(value=True)[source]¶ Set culling of polygons based on orientation of normal with respect to camera.

geodesic
(start, end)[source]¶ Dijkstra algorithm to compute the geodesic line. Takes as input a polygonal mesh and performs a single source shortest path calculation.
 Parameters

insidePoints
(pts, invert=False, tol=1e05, returnIds=False)[source]¶ Return the point cloud that is inside mesh surface.

intersectWith
(mesh2, tol=1e06)[source]¶ Intersect this Mesh with the input surface to return a line.
Hint

intersectWithLine
(p0, p1=None, returnIds=False)[source]¶ Return the list of points intersecting the mesh along the segment defined by two points p0 and p1.
 Parameters
returnIds (bool) – return the cell ids instead of point coords
 Example
from vedo import * s = Spring() pts = s.intersectWithLine([0,0,0], [1,0.1,0]) ln = Line([0,0,0], [1,0.1,0], c='blue') ps = Points(pts, r=10, c='r') show(s, ln, ps, bg='white')

isobands
(n=10, vmin=None, vmax=None)[source]¶ Return a new
Mesh
representing the isobands of the active scalars. This is a new mesh where the scalar is now associated to cell faces and used to colorize the mesh. Parameters

isolines
(n=10, vmin=None, vmax=None)[source]¶ Return a new
Mesh
representing the isolines of the active scalars. Parameters

join
(polys=True, reset=False)[source]¶ Generate triangle strips and/or polylines from input polygons, triangle strips, and lines.
Input polygons are assembled into triangle strips only if they are triangles; other types of polygons are passed through to the output and not stripped. Use mesh.triangulate() to triangulate nontriangular polygons prior to running this filter if you need to strip all the data.
Also note that if triangle strips or polylines are present in the input they are passed through and not joined nor extended. If you wish to strip these use mesh.triangulate() to fragment the input into triangles and lines prior to applying join().
 Parameters
 Warning
If triangle strips or polylines exist in the input data they will be passed through to the output data. This filter will only construct triangle strips if triangle polygons are available; and will only construct polylines if lines are available.
 Example
from vedo import * c1 = Cylinder(pos=(0,0,0), r=2, height=3, axis=(1,.0,0), alpha=.1).triangulate() c2 = Cylinder(pos=(0,0,2), r=1, height=2, axis=(0,.3,1), alpha=.1).triangulate() intersect = c1.intersectWith(c2).join(reset=True) spline = Spline(intersect).c('blue').lw(5) show(c1, c2, spline, intersect.labels('id'), axes=1)

lines
(flat=False)[source]¶ Get lines connectivity ids as a numpy array. Default format is [[id0,id1], [id3,id4], …]
 Parameters
flat (bool) – 1D numpy array as [2, 10,20, 3, 10,11,12, 2, 70,80, …]

reverse
(cells=True, normals=False)[source]¶ Reverse the order of polygonal cells and/or reverse the direction of point and cell normals. Two flags are used to control these operations:
cells=True reverses the order of the indices in the cell connectivity list.
 normals=True reverses the normals by multiplying the normal vector by 1
(both point and cell normals, if present).

shrink
(fraction=0.85)[source]¶ Shrink the triangle polydata in the representation of the input mesh.
Example
from vedo import * pot = load(datadir + 'teapot.vtk').shrink(0.75) s = Sphere(r=0.2).pos(0,0,0.5) show(pot, s)

silhouette
(direction=None, borderEdges=True, featureAngle=False)[source]¶ Return a new line
Mesh
which corresponds to the outer silhouette of the input as seen along a specified direction, this can also be avtkCamera
object. Parameters
direction (list) – viewpoint direction vector. If None this is guessed by looking at the minimum of the sides of the bounding box.
borderEdges (bool) – enable or disable generation of border edges
featureAngle (float) – minimal angle for sharp edges detection. If set to False the functionality is disabled.

smoothLaplacian
(niter=15, relaxfact=0.1, edgeAngle=15, featureAngle=60, boundary=False)[source]¶ Adjust mesh point positions using Laplacian smoothing.
 Parameters
niter (int) – number of iterations.
relaxfact (float) – relaxation factor. Small relaxfact and large niter are more stable.
edgeAngle (float) – edge angle to control smoothing along edges (either interior or boundary).
featureAngle (float) – specifies the feature angle for sharp edge identification.
Hint

smoothWSinc
(niter=15, passBand=0.1, edgeAngle=15, featureAngle=60, boundary=False)[source]¶ Adjust mesh point positions using the Windowed Sinc function interpolation kernel.
 Parameters

splitByConnectivity
(maxdepth=1000)[source]¶ Split a mesh by connectivity and order the pieces by increasing area.
 Parameters
maxdepth (int) – only consider this number of mesh parts.
:param bool addRegions

stretch
(q1, q2)[source]¶ Stretch mesh between points q1 and q2. Mesh is not affected.
Note
for
Mesh
objects like helices, Line, cylinders, cones etc., two attributesmesh.base
, andmesh.top
are already defined.

texture
(tname='', tcoords=None, interpolate=True, repeat=True, edgeClamp=False, scale=None, ushift=None, vshift=None, seamThreshold=None)[source]¶ Assign a texture to mesh from image file or predefined texture tname. If tname is set to
None
texture is disabled. If tname is set to ‘’ then a png or jpg file is looked for with same name and path. Input tname can also be an array of shape (n,m,3). Parameters
interpolate (bool) – turn on/off linear interpolation of the texture map when rendering.
repeat (bool) – repeat of the texture when tcoords extend beyond the [0,1] range.
edgeClamp (bool) – turn on/off the clamping of the texture map when the texture coords extend beyond the [0,1] range. Only used when repeat is False, and edge clamping is supported by the graphics card.
scale (bool) – scale the texture image by this factor
ushift (bool) – shift ucoordinates of texture by this amaount
vshift (bool) – shift vcoordinates of texture by this amaount
seamThreshold (float) – try to seal seams in texture by collapsing triangles (test values around 1.0, lower values = stronger collapse)

triangulate
(verts=True, lines=True)[source]¶ Converts mesh polygons into triangles.
If the input mesh is only made of 2D lines (no faces) the output will be a triangulation that fills the internal area. The contours may be concave, and may even contain holes, i.e. a contour may contain an internal contour winding in the opposite direction to indicate that it is a hole.