Module Mesh :: Class MFace

Class MFace

The MFace object

This object holds mesh face data.

Example:

import Blender
from Blender import Mesh, Window

in_emode = Window.EditMode()
if in_emode: Window.EditMode(0)

me = Mesh.Get("Mesh")
faces = me.faces

## Example for editmode faces selection:
selected_faces = []
for f in faces:
  if f.sel:
    selected_faces.append(f)
# ... unselect selected and select all the others:
for f in faces:
  f.sel = 1 - f.sel # 1 becomes 0, 0 becomes 1

## Example for UV textured faces selection:
selected_faces = []
SEL = Mesh.FaceFlags['SELECT']
# get selected faces:
for f in faces:
  if f.flag & SEL:
    selected_faces.append(f)
# ... unselect selected and select all the others:
for f in faces:
  if f.flag & SEL:
    f.flag &= ~SEL # unselect these
  else:
    f.flag |= SEL # and select these

if in_emode: Window.EditMode(1)
Blender.Redraw()

Notes:

there are regular faces and textured faces in Blender, both currently with their own selection and visibility states, due to a mix of old and new code. To (un)select or (un)hide regular faces (visible in EditMode), use MFace.sel and MFace.hide attributes. For textured faces (UV Face Select and Paint modes in Blender) use the MFace.flag attribute. Check the example above and note Window.EditMode.
Assigning UV textures to mesh faces in Blender works like this:
1. Select your mesh.
2. Enter face select mode (press f) and select at least some face(s).
3. In the UV/Image Editor window, load / select an image.
4. Play in both windows (better split the screen to see both at the same time) until the UV coordinates are where you want them. Hint: in the 3D window, the 'u' key opens a menu of default UV choices and the 'r' key lets you rotate the UV coords.
5. Leave face select mode (press f).

Method Summary
MVert	`__iter__()` Iterator for MVert.
int	`__len__()` len for MVert.

Instance Variable Summary
float	`area`: The area of the face.
vector	`cent`: The center of the face.
sequence of MCols	`col`: The face's vertex colors, if defined.
tuple	`edge_keys`: A tuple, each item a key that can reference an edge by its ordered indices.
	`flag`: The face's texture mode flags; indicates the selection, active , and visibility states of a textured face (see `FaceFlags` for values).
int	`hide`: The face's edit mode visibility state (hidden=1).
Image	`image`: The Image used as a texture for this face.
int	`index`: The face's index within the mesh.
int	`mat`: The face's index into the mesh's materials list.
int	`mode`: The texture mode bitfield (see `FaceModes`).
vector	`no`: The face's normal vector (x, y, z).
int	`sel`: The face's edit mode selection state (selected=1).
int	`smooth`: If set, the vertex normals are averaged to make this face look smooth.
int	`transp`: Transparency mode.
tuple of vectors (WRAPPED DATA)	`uv`: The face's UV coordinates.
tuple of ints	`uvSel`: The face's UV coordinates selection state; a 1 indicates the vertex is selected.
	`v`: Same as `verts`.
list of MVerts	`verts`: The face's vertices.

Method Details

iter()

Iterator for MVert. It iterates over the MVerts of the face, returning v1, v2, v3 (and optionally v4);

Returns:: one of the face's vertices
(type=MVert)

len()
(Length operator)

len for MVert. It returns the number of vertices in the face.

Returns:: int

Instance Variable Details

area

The area of the face. Read-only.

Type:: float

cent

The center of the face. Read-only.

Type:: vector

col

The face's vertex colors, if defined. Each vertex has its own color. Will throw an exception if the mesh does not have UV faces or vertex colors; use Mesh.faceUV and Mesh.vertexColors to test. Note: if a mesh has i{both} UV faces and vertex colors, the colors stored in the UV faces will be used here.

Example:

# This example uses vertex normals to apply normal colors to each face.
from Blender import Scene, Mesh, Window
scn= Scene.GetCurrent() # Current scene, important to be scene aware
ob= scn.getActiveObject() # last selected object
me= ob.getData(mesh=1) # thin wrapper doesn't copy mesh data like nmesh
me.faceUV=1                               # Enable face, vertex colors
for f in me.faces:
  for i, v in enumerate(f.v):
          no= v.no
          col= f.col[i]
          col.r= int((no.x+1)*128)
          col.g= int((no.y+1)*128)
          col.b= int((no.z+1)*128)
Window.RedrawAll()

Type:: sequence of MCols

edge_keys

A tuple, each item a key that can reference an edge by its ordered indices. Read-only. This is useful for building connectivity data. Example:

    from Blender import Mesh
    me = Mesh.Get('Cube')
    # a dictionary where the edge is the key, and a list of faces that use it are the value
    edge_faces = dict([(ed.key, []) for ed in me.edges])

    # Add the faces to the dict
    for f in me.faces:
        for key in f.edge_keys:
            edge_faces[key].append(f) # add this face to the edge as a user

    # Print the edges and the number of face users
    for key, face_users in edge_faces.iteritems():
        print 'Edge:', key, 'uses:', len(face_users),'faces'

Type:: tuple

flag

The face's texture mode flags; indicates the selection, active , and visibility states of a textured face (see FaceFlags for values). This is not the same as the selection or visibility states of the faces in edit mode (see sel and hide). To set the active face, use the Mesh.activeFace attribute instead. Will throw an exception if the mesh does not have UV faces; use Mesh.faceUV to test.

hide

The face's edit mode visibility state (hidden=1). This is not the same as the visibility state of the textured faces (see flag).

Type:: int

image

The Image used as a texture for this face. Setting this attribute will create UV faces if they do not exist. Getting this attribute throw an exception if the mesh does not have UV faces; use Mesh.faceUV to test. Assigning an image will automatically set the TEX attribute of the mode bitfield. Use "del f.image" or "f.image = None" to clear the image assigned to the face.

Type:: Image

index

The face's index within the mesh. Read-only.

Type:: int

mat

The face's index into the mesh's materials list. It is in the range [0,15].

Type:: int

mode

The texture mode bitfield (see FaceModes). Will throw an exception if the mesh does not have UV faces; use Mesh.faceUV to test.

Type:: int

no

The face's normal vector (x, y, z). Read-only.

Type:: vector

sel

The face's edit mode selection state (selected=1). This is not the same as the selection state of the textured faces (see flag). Note: changing the select state of a face changes the select state of the face's vertices.

Type:: int

smooth

If set, the vertex normals are averaged to make this face look smooth. (This is the same as choosing "Set Smooth" in the Editing Panel (F9) under "Link and Material" properties).

Type:: int

transp

Transparency mode. It is one of the values in FaceTranspModes). Will throw an exception if the mesh does not have UV faces; use Mesh.faceUV to test.

Type:: int

uv

The face's UV coordinates. Each vertex has its own UV coordinate. Setting this attribute will create UV faces if they do not exist. Getting this attribute throw an exception if the mesh does not have UV faces; use Mesh.faceUV to test.

Type:: tuple of vectors (WRAPPED DATA)

uvSel

The face's UV coordinates selection state; a 1 indicates the vertex is selected. Each vertex has its own UV coordinate select state (this is not the same as the vertex's edit mode selection state). Setting this attribute will create UV faces if they do not exist. Getting this attribute throw an exception if the mesh does not have UV faces; use Mesh.faceUV to test.

Type:: tuple of ints

v

Same as verts. This attribute is only for compatibility with NMesh scripts and will probably be deprecated in the future.

verts

The face's vertices. Each face has 3 or 4 vertices.

Type:: list of MVerts

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