121 lines
3.1 KiB
Python
121 lines
3.1 KiB
Python
from __future__ import division
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import pprint
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'''
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http://en.wikipedia.org/wiki/Polygon_mesh
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Polygon meshes may be represented in a variety of ways, using different methods
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to store the vertex, edge and face data. These include:
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- Face-vertex
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- Winged-edge
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- Half-edge
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- Quad-edge
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- Corner-tables
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- Vertex-vertex
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- Face-vertex
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We have chosen to use a winged-edge style mesh for our purpopses.
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'''
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def cross(a, b):
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i = a.y * b.z - a.z * b.y
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j = a.z * b.x - a.x * b.z
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k = a.x * b.y - a.y * b.x
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return Vertex(i, j, k)
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class Vertex(object):
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'''
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A vertex is a position along with other information such as color, normal
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vector and texture coordinates.
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'''
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def __init__(self, polygon, x=0, y=0, z=0):
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self.polygon = polygon
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self.x = x
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self.y = y
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self.z = z
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self.edges = []
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def __eq__(self, other):
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if(self.x == other.x and self.y == other.y and self.z == other.z):
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return True
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else:
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return False
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def __repr__(self):
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return "[%.2f, %.2f, %.2f]" % (self.x, self.y, self.z)
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def __add__(self, other):
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# for now just assume type(other) = Vertex... bad, I know
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return Vertex(self.x + other.x, self.y + other.y, self.z + other.z)
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def __radd__(self, other):
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return other + self
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# return self.__add__(other)
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def __mul__(self, other):
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if isinstance(other, Vertex):
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return cross(self, other)
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elif isinstance(other, (float, int)):
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return Vertex(self.x * other, self.y * other, self.z * other)
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else:
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raise TypeError("{0} has an unexpected type: {1}".format(
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other, type(other)))
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def __rmul__(self, other):
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return self.__mul__(other)
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def __div__(self, other):
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# same assumption as __mult__
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return Vertex(self.x / other, self.y / other, self.z / other)
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__truediv__ = __div__
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def __neg__(self):
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return Vertex(-self.x, -self.y, -self.z)
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class Edge(object):
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'''
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'''
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def __init__(self, polygon):
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self.polygon = polygon
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self.vertices = []
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self.faces = []
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self.edges = []
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def neighborFace(self, neighborFace):
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'''Get neighboring face id
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'''
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if neighborFace == self.faces[0]:
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return self.faces[1]
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else:
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return self.faces[0]
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class Face(object):
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'''
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A face is a closed set of edges, in which a triangle face has three edges,
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and a quad face has four edges.
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'''
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def __init__(self, polygon):
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self.polygon = polygon
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self.edges = []
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class Polygon(object):
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'''
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'''
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def __init__(self, vs=None, es=None, fs=None):
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self.vertices = vs or []
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self.edges = es or []
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self.faces = fs or []
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def __unicode__(self):
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d = {
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'vertices': self.vertices,
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'edges': self.edges,
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'faces': self.faces,
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}
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return pprint.pformat(d)
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__str__ = __unicode__
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__repr__ = __unicode__ |