The NMesh Data object

addEdge(v1, v2)

Parameters:

v1 - the first vertex of the edge.
           (type=NMVert)

v2 - the second vertex of the edge.
           (type=NMVert)

Returns:

The created or already existing edge.
           (type=NMEdge)

Note: In Blender only zero or one edge can link two vertices.

addEdgesData()

addFace(face)

Parameters:

face - the face to add to the mesh.
           (type=NMFace)

Returns:

If mesh has edge data, return the list of face edges.
           (type=list of NMEdge)

addMaterial(material)

Parameters:

material - A Blender Material.
           (type=Blender Material)

addVertGroup(group)

Add a named and empty vertex (deform) group to the object this nmesh is linked to. If this nmesh was newly created or accessed with GetRaw, it must first be linked to an object (with object.link or NMesh.PutRaw) so the method knows which object to update.

Parameters:

group - the name for the new group.
           (type=string)

assignVertsToGroup(group, vertList, weight, assignmode='replace')

Adds an array (a python list) of vertex points to a named vertex group associated with a mesh. The vertex list is a list of vertex indices from the mesh. You should assign vertex points to groups only when the mesh has all its vertex points added to it and is already linked to an object.

import Blender
sphere = Blender.Object.Get('Sphere')
mesh = sphere.getData()
mesh.addVertGroup('firstGroup')
vertList = []
for x in range(300):
    if x % 3 == 0:
        vertList.append(x)
mesh.assignVertsToGroup('firstGroup', vertList, 0.5, 'add')

Parameters:

group - the name of the group.
           (type=string)

vertList - a list of vertex indices.
           (type=list of ints)

weight - the deform weight for (which means: the amount of influence the group has over) the given vertices. It should be in the range [0.0, 1.0]. If weight <= 0, the given vertices are removed from the group. If weight > 1, it is clamped.
           (type=float)

assignmode - Three choices:

• 'add'
• 'substract'

• 'replace'

  'add': if the vertex in the list is not assigned to the group already, this creates a new association between this vertex and the group with the weight specified, otherwise the weight given is added to the current weight of an existing association between the vertex and group.

  'subtract' will attempt to subtract the weight passed from a vertex already associated with a group, else it does nothing.

  'replace' attempts to replace a weight with the new weight value for an already associated vertex/group, else it does nothing.

           (type=string)

findEdge(v1, v2)

Parameters:

v1 - the first vertex of the edge.
           (type=NMVert)

v2 - the second vertex of the edge.
           (type=NMVert)

Returns:

The found edge. None if no edge was found.
           (type=NMEdge)

getActiveFace()

Returns:

The index of the active face.
           (type=int)

getMaterials(what=-1)

Parameters:

what - determines the list's contents:

• -1: return the current nmesh's list;
• 0: retrieve a fresh list from the Blender mesh -- eventual modifications made by the script not included, unless NMesh.updated is called before this method;
• 1: like 0, but empty slots are not ignored, they are returned as None's.

           (type=int)

Returns:

the requested list of materials.
           (type=list of materials)

Notes:

• what >= 0 also updates nmesh.materials attribute.
• if a user goes to the material buttons window and removes some mesh's link to a material, that material slot becomes empty. Previously such materials were ignored.

getMaxSmoothAngle()

Returns:

The value in degrees.

getMode()

Returns:

Or'ed value. See Modes.
           (type=int)

getSelectedFaces(flag=None)

Parameters:

flag - If given and non-zero, the list will have indices instead of the NMFace objects themselves.
           (type=int)

Returns:

It depends on the flag parameter:

• if None or zero: List of NMFace objects.
• if non-zero: List of indices to NMFace objects.

           (type=list)

Warning: this method exists to speed up retrieving of selected faces from the actual mesh in Blender. So, if you make changes to the nmesh, you need to update it before using this method.

getSubDivLevels()

Returns:

list of ints: [display, render].

getVertexInfluences(index)

Parameters:

index - The index of a vertex.
           (type=int)

Returns:

List of pairs (name, weight), where name is the bone name (string) and its weight is a float value.
           (type=list of lists)

getVertGroupNames()

Returns:

returns a list of strings representing all vertex group associated with the mesh's object
           (type=list of strings)

getVertsFromGroup(group, weightsFlag=0, vertList=None)

Return a list of vertex indices associated with the passed group. This method can be used to test whether a vertex index is part of a group and if so, what its weight is.

# ...
print "Vertex indices from group %s :" % groupName
print mesh.getVertsFromGroup('firstGroup')
print "Again, with weights:"
print mesh.getVertsFromGroup('firstGroup',1)
print "Again, with weights and restricted to the given indices:"
print mesh.getVertsFromGroup('firstGroup',1,[1,2,3,4,5,6])     

Parameters:

group - the group name.
           (type=string)

weightsFlag - if 1, the weight is returned along with the index.
           (type=bool)

vertList - if given, only those vertex points that are both in the list and group passed in are returned.
           (type=list of ints)

hasFaceUV(flag=None)

Parameters:

flag - If given and non-zero, the "textured faces" flag for this NMesh is turned on.
           (type=int)

Returns:

The current value of the "textured faces" flag.
           (type=bool)

hasVertexColours(flag=None)

Parameters:

flag - If given and non-zero, the "vertex colour" flag for this NMesh is turned on.
           (type=int)

Returns:

The current value of the "vertex colour" flag.
           (type=bool)

Warning: If a mesh has both vertex colours and textured faces, this function will return False. This is due to the way Blender deals internally with the vertex colours array (if there are textured faces, it is copied to the textured face structure and the original array is freed/deleted). If you want to know if a mesh has both textured faces and vertex colours, set *in Blender* the "VCol Paint" flag for each material that covers an area that was also vertex painted and then check in your Python script if that material flag is set. Of course also tell others who use your script to do the same. The "VCol Paint" material mode flag is the way to tell Blender itself to render with vertex colours, too, so it's a natural solution.

hasVertexUV(flag=None)

Parameters:

flag - If given and non-zero, the "sticky" flag for this NMesh is turned on.
           (type=int)

Returns:

The current value of the "sticky" flag.
           (type=bool)

insertKey(frame=None, type='relative')

Parameters:

frame - The Scene frame where the mesh key should be inserted. If None, the current frame is used.
           (type=int)

type - The mesh key type: 'relative' or 'absolute'. This is only relevant on the first call to insertKey for each nmesh (and after all keys were removed with removeAllKeys, of course).
           (type=string)

Warning: This and removeAllKeys were included in this release only to make accessing vertex keys possible, but may not be a proper solution and may be substituted by something better later. For example, it seems that 'frame' should be kept in the range [1, 100] (the curves can be manually tweaked in the Ipo Curve Editor window in Blender itself later).

removeAllKeys()

Returns:

True if successful or False if this NMesh wasn't linked to a real Blender Mesh yet (or was, but the Mesh had no keys).
           (type=bool)

Warning: Currently the mesh keys from meshes that are grabbed with NMesh.GetRaw() or .GetRawFromObject() are preserved, so if you want to clear them or don't want them at all, remember to call this method. Of course NMeshes created with NMesh.New() don't have mesh keys until you add them.

removeEdge(v1, v2)

Parameters:

v1 - the first vertex of the edge.
           (type=NMVert)

v2 - the second vertex of the edge.
           (type=NMVert)

removeFace(face)

Parameters:

face - the face to add to the mesh.
           (type=NMFace)

removeVertGroup(group)

Parameters:

group - the name of a vertex group.
           (type=string)

removeVertsFromGroup(group, vertList=None)

Parameters:

group - the name of a vertex group
           (type=string)

vertList - a list of vertex indices to be removed from the given 'group'. If None, all vertices are removed -- the group is emptied.
           (type=list of ints)

renameVertGroup(groupName, newName)

Parameters:

groupName - the vertex group name to be renamed.
           (type=string)

newName - the name to replace the old name.
           (type=string)

setMaterials(matlist)

Parameters:

matlist - a list with materials, None's also accepted (they become empty material slots in Blender.
           (type=list of materials)

setMaxSmoothAngle(angle)

Parameters:

angle - The new value in degrees -- it's clamped to [1, 80].
           (type=int)

setMode(m=None, m1=None, m2=None, m3=None)

Parameters:

m - mode string or int. An int (see Modes) or from none to 5 strings can be given:

• "NoVNormalsFlip"
• "TwoSided"
• "AutoSmooth"
• "SubSurf"
• "Optimal"

           (type=string or int (bitflag))

setSubDivLevels(subdiv)

Parameters:

subdiv - new subdiv levels: [display, render]. Both are clamped to lie in the range [1, 6].
           (type=list of 2 ints)

transform(matrix, recalc_normals=False)

Transforms the mesh by the specified 4x4 matrix, as returned by Object.Object.getMatrix, though this will work with any invertible 4x4 matrix type. Ideal usage for this is exporting to an external file where global vertex locations are required for each object. Sometimes external renderers or file formats do not use vertex normals. In this case, you can skip transforming the vertex normals by leaving the optional parameter recalc_normals as False or 0 ( the default value ).

# This script outputs deformed meshes worldspace vertex locations
# for a selected object
import Blender
from Blender import NMesh, Object

ob = Object.GetSelected()[0] # Get the first selected object
me = NMesh.GetRawFromObject(ob.name) # Get the objects deformed mesh data
me.transform(ob.matrix)

for v in me.verts:
  print 'worldspace vert', v.co

Parameters:

matrix - 4x4 Matrix which can contain location, scale and rotation.
           (type=Py_Matrix)

recalc_normals - if True or 1, transform normals as well as vertex coordinates.
           (type=int (bool))

Warning: if you call this method and later update the mesh, the new vertex positions will be passed back to Blender, but the object matrix of each object linked to this mesh won't be automatically updated. You need to set the object transformations (rotation, translation and scaling) to identities, then, or the mesh data will be changed ("transformed twice").

update(recalc_normals=0, store_edges=0, vertex_shade=0)

Parameters:

recalc_normals - if nonzero the vertex normals are recalculated.
           (type=int (bool))

store_edges - if nonzero, then edge data is stored.
           (type=int (bool))

vertex_shade - if nonzero vertices are colored based on the current lighting setup, like when there are no vertex colors and no textured faces and a user enters Vertex Paint Mode in Blender (only lamps in visible layers account). To use this functionality, be out of edit mode or else an error will be returned.
           (type=int (bool))

Warnings:

• edit mesh and normal mesh are two different structures in Blender, synchronized upon leaving or entering edit mode. Always remember to leave edit mode (Window.EditMode) before calling this update method, or your changes will be lost. Even better: for the same reason programmers should leave EditMode before getting a mesh, or changes made to the editmesh in Blender may not be visible to your script (check the example at the top of NMesh module doc).
• unlike the PutRaw function, this method doesn't check validity of vertex, face and material lists, because it is meant to be as fast as possible (and already performs many tasks). So programmers should make sure they only feed proper data to the nmesh -- a good general recommendation, of course. It's also trivial to write code to check all data before updating, for example by comparing each item's type with the actual Types, if you need to.

Notes:

• this method also redraws the 3d view and -- if 'vertex_shade' is nonzero -- the edit buttons window.
• if your mesh disappears after it's updated, try Object.Object.makeDisplayList. 'Subsurf' meshes (see getMode, setMode) need their display lists updated, too.