sm
/
surfaces
1
0
Fork 0
Code Issues Pull Requests Activity

Cleaned up some pep8 violations 

- changed camelCase variables to under_case
    - wrapped lines that were longer than 80 chars
    - used @property decorator
    - changed the cc refine test to print before running refine
        - refine seems to be destructive
This commit is contained in:
Stephen M. McQuay 2012-03-19 22:56:12 -06:00
parent 84712d5613
commit 9a5fc54f12
3 changed files with 178 additions and 141 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

255
surf/geometry.py
View File

@ -3,16 +3,18 @@ import pprint
'''
http://en.wikipedia.org/wiki/Polygon_mesh
Polygon meshes may be represented in a variety of ways, using different methods to store the vertex, edge and face data. These include:
Face-vertex meshes: A simple list of vertices, and a set of polygons that vertex to the vertices it uses.
Winged-edge meshes, in which each edge vertices to two vertices, two faces, and the four (clockwise and counterclockwise) edges that touch it. Winged-edge meshes allow constant time traversal of the surface, but with higher storage requirements.
Half-edge meshes: Similar to winged-edge meshes except that only half the edge traversal information is used.
Quad-edge meshes, which store edges, half-edges, and vertices without any reference to polygons. The polygons are implicit in the representation, and may be found by traversing the structure. Memory requirements are similar to half-edge meshes.
Corner-tables, which store vertices in a predefined table, such that traversing the table implicitly defines polygons. This is in essence the "triangle fan" used in hardware graphics rendering. The representation is more compact, and more efficient to retrieve polygons, but operations to change polygons are slow. Furthermore, corner-tables do not represent meshes completely. Multiple corner-tables (triangle fans) are needed to represent most meshes.
Vertex-vertex meshes: A "VV" mesh represents only vertices, which vertex to other vertices. Both the edge and face information is implicit in the representation. However, the simplicity of the representation allows for many efficient operations to be performed on meshes.
Polygon meshes may be represented in a variety of ways, using different methods
to store the vertex, edge and face data. These include:
- Face-vertex
- Winged-edge
- Half-edge
- Quad-edge
- Corner-tables
- Vertex-vertex
- Face-vertex
We have chosen to use a winged-edge style mesh for our purpopses.
Face-vertex meshes represent an object as a set of faces and a set of vertices. This is the most widely used mesh representation, being the input typically accepted by modern graphics hardware.
v4 v5
*-----e8-----*
| |
@ -48,7 +50,7 @@ Polygon meshes may be represented in a variety of ways, using different methods
v5 - <1,1,1>
v6 - <1,0,1>
v7 - <0,0,1>
face list
f0 - e0, e1, e2, e3
f1 - e1, e5, e9, e6
@ -56,7 +58,7 @@ Polygon meshes may be represented in a variety of ways, using different methods
f3 - e4, e3, e7, e11
f4 - e8, e5, e0, e4
f5 - e10, e9, e8, e11
winged edges ordered by face, then by vertex reference
edge list
e0 - v0, v1; f0, f4; e3, e1, e4, e5
@ -71,7 +73,7 @@ Polygon meshes may be represented in a variety of ways, using different methods
e9 - v5, v6; f1, f5; e5, e6, e8, e10
e10 - v7, v6; f2, f5; e7, e6, e11, e9
e11 - v4, v7; f3, f5; e4, e7, e8, 10
vertex list
v0 - e0, e3, e4
v1 - e0, e5, e1
@ -81,12 +83,14 @@ Polygon meshes may be represented in a variety of ways, using different methods
v5 - e5, e9, e8
v6 - e2, e9, e10
v7 - e7, e10, e11
'''
class Vertex(object):
'''
A vertex is a position along with other information such as color, normal vector and texture coordinates.
A vertex is a position along with other information such as color, normal
vector and texture coordinates.
'''
def __init__(self, x=0, y=0, z=0):
self.x = x
@ -100,29 +104,29 @@ class Vertex(object):
else:
return False
def __repr__(self):
return "[%.2f, %.2f, %.2f]" % (self.x, self.y, self.z)
def __add__(self, other):
# for now just assume type(other) = Vertex... bad, I know
return Vertex(self.x + other.x, self.y + other.y, self.z + other.z)
return Vertex(self.x + other.x, self.y + other.y, self.z + other.z)
def __radd__(self, other):
return self.__add__(other)
def __mul__(self, other):
def __mul__(self, other):
# for now just assume type(other) = int or float
return Vertex(self.x * other, self.y * other, self.z * other)
def __rmul__(self, other):
return self.__mul__(other)
def __div__(self, other):
# same assumption as __mult__
other = float(other)
return Vertex(self.x / other, self.y / other, self.z / other)
class Edge(object):
'''
'''
@ -130,87 +134,90 @@ class Edge(object):
self.vertices = []
self.faces = []
self.edges = []
self.__edgeVertex = None
self.__subEdges = []
self.__edge_vertex = None
self.__sub_edges = []
def neighborFace(self, neighborFace):
if neighborFace == self.faces[0]:
return self.faces[1]
else:
return self.faces[0]
def __getMidPoint(self):
return sum(self.vertices) / len(self.vertices)
midPoint = property(fget=__getMidPoint)
def __getSubEdges(self):
if not self.__subEdges:
self.__subEdges = [Edge(), Edge()]
self.__subEdges[0].vertices = [self.vertices[0], self.edgeVertex]
self.__subEdges[1].vertices = [self.edgeVertex, self.vertices[1]]
return self.__subEdges
subEdges = property(fget=__getSubEdges)
def __getEdgeVertex(self):
@property
def mid_point(self):
return sum(self.vertices, Vertex()) / len(self.vertices)
@property
def sub_edges(self):
if not self.__sub_edges:
self.__sub_edges = [Edge(), Edge()]
self.__sub_edges[0].vertices = [self.vertices[0], self.edge_vertex]
self.__sub_edges[1].vertices = [self.edge_vertex, self.vertices[1]]
return self.__sub_edges
@property
def edge_vertex(self):
'''
Set each edge vertices to be the average of the two neighboring
face vertices and its two original end vertices.
'''
if not self.__edgeVertex:
if not self.__edge_vertex:
# two neighboring face vertices:
neighboringFaceVertices = [face.centroid for face in self.faces]
neighboringFaceVertices.extend(self.vertices)
xs = [vertex.x for vertex in neighboringFaceVertices]
ys = [vertex.y for vertex in neighboringFaceVertices]
zs = [vertex.z for vertex in neighboringFaceVertices]
x = sum(xs)/len(xs)
y = sum(ys)/len(ys)
z = sum(zs)/len(zs)
self.__edgeVertex = Vertex(x, y, z)
self.__edgeVertex.edges.extend(self.__subEdges)
return self.__edgeVertex
edgeVertex = property(fget=__getEdgeVertex)
x = sum(xs) / len(xs)
y = sum(ys) / len(ys)
z = sum(zs) / len(zs)
self.__edge_vertex = Vertex(x, y, z)
self.__edge_vertex.edges.extend(self.__sub_edges)
return self.__edge_vertex
def __averageVertices(self, vertices):
return
return
class Face(object):
'''
A face is a closed set of edges, in which a triangle face has three edges, and a quad face has four edges.
A face is a closed set of edges, in which a triangle face has three edges,
and a quad face has four edges.
'''
def __init__(self):
self.edges = []
self.__centroid = None
self.__interiorEdges = []
self.__subFaces = []
def __getCentroid(self):
self.__interior_edges = []
self.__sub_faces = []
@property
def centroid(self):
if not self.__centroid:
# gather all face vertex coords
faceVertices = list(set([vertex for edge in self.edges for vertex in edge.vertices]))
xs = [vertex.x for vertex in faceVertices]
ys = [vertex.y for vertex in faceVertices]
zs = [vertex.z for vertex in faceVertices]
face_vertices = list(set([vertex
for edge in self.edges for vertex in edge.vertices]))
xs = [vertex.x for vertex in face_vertices]
ys = [vertex.y for vertex in face_vertices]
zs = [vertex.z for vertex in face_vertices]
# average each vertex component
x = sum(xs) / len(xs)
y = sum(ys) / len(ys)
z = sum(zs) / len(zs)
self.__centroid = Vertex(x, y, z)
return self.__centroid
centroid = property(fget=__getCentroid)
def __getSubFaces(self):
@property
def sub_faces(self):
self.__setupSubDivisions()
return self.__subFaces
subFaces = property(fget=__getSubFaces)
def __getInteriorEdges(self):
return self.__sub_faces
@property
def interior_edges(self):
self.__setupSubDivisions()
return self.__interiorEdges
interiorEdges = property(fget=__getInteriorEdges )
return self.__interior_edges
def __setupSubDivisions(self):
'''
v0 ev0 v1
@ -223,58 +230,78 @@ class Face(object):
*------e2-----*
v3 ev2 v2
'''
if not self.__subFaces:
# create empty subFaces that will be filled with edge references below
# these need to at least exist so the interior edges have something to reference
self.__subFaces = [Face() for edge in self.edges]
if not self.__interiorEdges:
if not self.__sub_faces:
# create empty sub_faces that will be filled with edge references
# below
# these need to at least exist so the interior edges have
# something to reference
self.__sub_faces = [Face() for edge in self.edges]
if not self.__interior_edges:
# set up empty edge objects to be filled below
self.__interiorEdges = [Edge() for edge in self.edges]
# each interior edge connects the exterior edge vertex (mid-point) to the faceVertex (centroid)
self.__interior_edges = [Edge() for edge in self.edges]
# each interior edge connects the exterior edge vertex (mid-point)
# to the faceVertex (centroid)
for index in range(len(self.edges)):
prevIndex = (index - 1) % len(self.edges)
nextIndex = (index + 1) % len(self.edges)
# end vertices are face centroid and currEdge edgeVertex
self.__interiorEdges[index].vertices = [self.edges[index].edgeVertex,
self.centroid]
# wing edges are the current edge's subEdges (ordered same as vertex order) and the prev and next interior edges
self.__interiorEdges[index].edges = [self.edges[index].subEdges[0],
self.edges[index].subEdges[1],
self.__interiorEdges[prevIndex],
self.__interiorEdges[nextIndex]]
# edge faces are the new subFaces (current and next faces), the current will be define below
# and the next will be defined on the next iteration (or already defined on the last iteration)
self.__interiorEdges[index].faces = [self.__subFaces[index],
self.__subFaces[nextIndex]]
# end vertices are face centroid and currEdge edge_vertex
self.__interior_edges[index].vertices = [
self.edges[index].edge_vertex, self.centroid
]
# wing edges are the current edge's sub_edges (ordered same as
# vertex order) and the prev and next interior edges
self.__interior_edges[index].edges = [
self.edges[index].sub_edges[0],
self.edges[index].sub_edges[1],
self.__interior_edges[prevIndex],
self.__interior_edges[nextIndex]
]
# edge faces are the new sub_faces (current and next faces), the
# current will be define below
# and the next will be defined on the next iteration (or
# already defined on the last iteration)
self.__interior_edges[index].faces = [
self.__sub_faces[index],
self.__sub_faces[nextIndex]
]
# now reference the current edge back into the faces,
# and the edge.subEdges, and the edge.edgeVertex
# and the edge.sub_edges, and the edge.edge_vertex
# current subFace (same index as current interior edge)
# set its edges to reference the same edges used to setup the interior edge
# set its edges to reference the same edges used to setup the
# interior edge
# order will be pretty important on these steps...
self.__subFaces[index].edges = [self.edges[index].subEdges[0],
self.__interiorEdges[index],
self.__interiorEdges[prevIndex],
self.edges[prevIndex].subEdges[1]]
# just set one of the vertex edges, the other belongs to another face and will get added when that face is run
self.edges[index].edgeVertex.edges.append(self.__interiorEdges[index])
self.edges[index].subEdges[0].faces.append(self.__subFaces[index])
self.edges[index].subEdges[0].faces.append(self.__subFaces[index])
self.__sub_faces[index].edges = [
self.edges[index].sub_edges[0],
self.__interior_edges[index],
self.__interior_edges[prevIndex],
self.edges[prevIndex].sub_edges[1]
]
# just set one of the vertex edges, the other belongs to
# another face and will get added when that face is run
self.edges[index].edge_vertex.edges.append(
self.__interior_edges[index])
self.edges[index].sub_edges[0].faces.append(
self.__sub_faces[index])
self.edges[index].sub_edges[0].faces.append(
self.__sub_faces[index])
class Polygon(object):
'''
Face splitting should happend on the polygon level(?). It doesn't make sense to split just one face since
it needs to average vertices with all adjoinging faces
Face splitting should happend on the polygon level(?). It doesn't make
sense to split just one face since it needs to average vertices with all
adjoinging faces
'''
def __init__(self, v=None, e=None, f=None):
self.vertices = v or []
self.edges = e or []

60
surf/subd/cc.py
View File

@ -1,53 +1,63 @@
from surf.geometry import Vertex, Polygon
def refine(poly):
'''
For each face, add a face vertex
Set each face vertex to be the centroid of all original vertices for the respective face.
Set each face vertex to be the centroid of all original vertices for
the respective face.
For each edge, add an edge vertex.
Set each edge vertex to be the average of the two neighbouring face vertices and its two original endvertices.
For each face vertex, add an edge for every edge of the face, connecting the face vertex to each edge vertex for the face.
For each original vertex P, take the average F of all n face vertices for faces touching P, and take the average R of all n edge midvertices for edges touching P, where each edge midvertex is the average of its two endvertex vertices. Move each original vertex to the vertex
Set each edge vertex to be the average of the two neighbouring face
vertices and its two original endvertices.
For each face vertex, add an edge for every edge of the face, connecting
the face vertex to each edge vertex for the face.
For each original vertex P, take the average F of all n face vertices for
faces touching P, and take the average R of all n edge midvertices for
edges touching P, where each edge midvertex is the average of its two
endvertex vertices. Move each original vertex to the vertex
'''
# each face knows how to subdivide and create a set of subfaces, including interior edges and setup their references correctly... <- not completely finished...
# each face knows how to subdivide and create a set of subfaces, including
# interior edges and setup their references correctly... <- not completely
# finished...
p = Polygon()
edges = []
vertices = []
faces = []
for face in poly.faces:
for subFace in face.subFaces:
for subFace in face.sub_faces:
faces.append(subFace)
for edge in subFace.edges:
edges.append(edge)
for vertex in edge.vertices:
vertices.append(vertex)
newVertices = []
for vertex in poly.vertices:
faceVertices = []
edgeMidPoints = []
face_vertices = []
edge_mid_points = []
for edge in vertex.edges:
edgeMidPoints.append(edge.midPoint)
edge_mid_points.append(edge.mid_point)
for face in edge.faces:
faceVertices.append(face.centroid)
f = sum(list(set(faceVertices)), Vertex())/len(list(set(faceVertices)))
r = sum(list(set(edgeMidPoints)), Vertex())/len(list(set(edgeMidPoints)))
face_vertices.append(face.centroid)
f = sum(list(
set(face_vertices)), Vertex()) / len(list(set(face_vertices)))
r = sum(list(
set(edge_mid_points)), Vertex()) / len(list(set(edge_mid_points)))
p = vertex
n = len(vertex.edges)
v = (f + 2.0 * r + (n - 3.0) * p) / n
newVertices.append(v)
for vertex, newVertex in zip(poly.vertices, newVertices):
vertex.x = newVertex.x
vertex.y = newVertex.y
vertex.z = newVertex.z
# so now what.........
# (F + 2R + (n-3) P) / n
#
#
# F = average of all face vertices touching P
# R = average of all edge vertices touching P
# P original point
@ -56,13 +66,13 @@ def refine(poly):
p.faces = faces
p.vertices = vertices
p.edges = edges
# plotting these in excel seems to show the correct values (at first glace...)
# so now what.........
# plotting these in excel seems to show the correct values (at first
# glace...)
# so now what.........
# (F + 2R + (n-3) P) / n
#
#
# F = average of all face vertices touching P
# R = average of all edge vertices touching P
# P original point

4
test/test00.py
View File

@ -2,9 +2,9 @@ from surf.util import cube
from surf.subd import cc
polygon = cube()
refined_poly = cc.refine(polygon)
print polygon
refined_poly = cc.refine(polygon)
print refined_poly
#
#