From 6c516e26fcbf53b5aca38392e0e7e86eb9b685e2 Mon Sep 17 00:00:00 2001 From: "Stephen M. McQuay" Date: Mon, 7 May 2012 23:21:31 -0600 Subject: [PATCH] updated the surf.geometry module to better map to blender primatives --- surf/geometry.py | 268 +++++++++++++++++++++-------------------------- 1 file changed, 121 insertions(+), 147 deletions(-) diff --git a/surf/geometry.py b/surf/geometry.py index 7dc44e5..2e39f23 100644 --- a/surf/geometry.py +++ b/surf/geometry.py @@ -18,38 +18,53 @@ We have chosen to use a winged-edge style mesh for our purpopses. ''' + def cross(a, b): i = a.y * b.z - a.z * b.y j = a.z * b.x - a.x * b.z k = a.x * b.y - a.y * b.x return Vertex(i, j, k) - + +def _centroid(verts): + xs = [vertex.x for vertex in verts] + ys = [vertex.y for vertex in verts] + zs = [vertex.z for vertex in verts] + + # average each vertex component + x = sum(xs) / len(xs) + y = sum(ys) / len(ys) + z = sum(zs) / len(zs) + + return Vertex(x, y, z) + + class Vertex(object): ''' A vertex is a position along with other information such as color, normal vector and texture coordinates. + + For the sake of our algorithms, we will only worry about the (x, y, z) + float positions. Eventually we will also keep track of weights. ''' def __init__(self, x=0.0, y=0.0, z=0.0): - ''' - ''' self.x = x self.y = y self.z = z - + def __eq__(self, other): if(self.x == other.x and self.y == other.y and self.z == other.z): return True else: return False - + 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) - + def __radd__(self, other): return other + self - + def __mul__(self, other): if isinstance(other, Vertex): return cross(self, other) @@ -58,183 +73,142 @@ class Vertex(object): else: raise TypeError("{0} has an unexpected type: {1}".format( other, type(other))) - + def __rmul__(self, other): return self.__mul__(other) - + def __div__(self, other): # same assumption as __mult__ return Vertex(self.x / other, self.y / other, self.z / other) __truediv__ = __div__ - + def __neg__(self): return Vertex(-self.x, -self.y, -self.z) - + def __unicode__(self): - d = { - 'id': self.id, - 'parent_id': self.parent_id, - 'coords': [self.x, self.y, self.z] - } - return pprint.pformat(d) - + return pprint.pformat([self.x, self.y, self.z]) + __str__ = __unicode__ __repr__ = __unicode__ class Edge(object): - ''' - ''' - - next_id = 0 - def __init__(self, polygon, parent_id=None, vs=None, es=None, fs=None): - ''' - ''' - self.polygon = polygon - self.parent_id = parent_id - self.vertex_ids = vs or [] - self.edge_ids = es or [] - self.face_ids = fs or [] - self.id = Edge.next_id - Edge.next_id += 1 - - def neighbor_face_id(self, neighbor_face_id): - '''Get neighboring face id - ''' - if neighbor_face_id == self.face_ids[0]: - return self.face_ids[1] - else: - return self.face_ids[0] - + def __init__(self, v1, v2): + self.v1 = v1 + self.v2 = v2 + + @property + def centroid(self): + return _centroid([self.v1, self.v2]) + def __unicode__(self): - d = { - 'id': self.id, - 'vertex_ids': self.vertex_ids, - 'edge_ids': self.edge_ids, - 'face_ids': self.face_ids, - } - return pprint.pformat(d) - + return pprint.pformat((self.v1, self.v2)) + __str__ = __unicode__ __repr__ = __unicode__ - - @property - def vertices(self): - return [self.polygon.vertex(v_id) for v_id in self.vertex_ids] - - @property - def faces(self): - return [self.polygon.face(f_id) for f_id in self.face_ids] - - def winged_edges_at_vertex(self, index): - edge_ids = [] - for edge in self.edges: - if self.vertex_ids[index] in edge.vertex_ids: - edge_ids.append(edge.id) - return edge_ids + 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. Blender stores a face as a collection of + the verts that compose it, so we shall store them thusly as well. + + Blender historicaly only supported faces with an edge count of three or + four. We will cross the N-gon bridge in the future. ''' - - next_id = 0 - def __init__(self, polygon, parent_id=None, es=None): - ''' - ''' - self.polygon = polygon - self.parent_id = parent_id - self.edge_ids = es or [] - self.id = Face.next_id - Face.next_id += 1 - + + def __init__(self, verts=None): + self.verts = verts or [] + def __unicode__(self): - d = {'id': self.id, 'edge_ids': self.edge_ids} - return pprint.pformat(d) - + return pprint.pformat(self.verts) + __str__ = __unicode__ __repr__ = __unicode__ - def edge(self, edge_id): - return self.polygon.edge(edge_id) - - @property - def edges(self): - return [self.polygon.edge(e_id) for e_id in self.edge_ids] - - @property - def vertices(self): - vertices = [] - for edge_id in self.edge_ids: - edge = self.polygon.edge(edge_id) - vertices.extend(edge.vertices) - - return list(set(vertices)) - @property def centroid(self): - ''' - ''' - - # gather all face vertex coords - face_vertices = self.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] + return _centroid(self.verts) - # average each vertex component - x = sum(xs) / len(xs) - y = sum(ys) / len(ys) - z = sum(zs) / len(zs) - - return [x, y, z] - -class Polygon(object): +class PolygonMesh(object): ''' - ''' - - def __init__(self, vs=None, es=None, fs=None): - self.vertices = vs or [] - self.edges = es or [] - self.faces = fs or [] - - def face(self, face_id): - for face in self.faces: - if face.id == face_id: - return face - return None - - def edge(self, edge_id): - for edge in self.edges: - if edge.id == edge_id: - return edge - return None - - def vertex(self, vertex_id): - for vertex in self.vertices: - if vertex.id == vertex_id: - return vertex - return None + A polygon object is a collection of the following lists: + + - a list containing the 3-space vertex information + - a list containing the edge indices ([0, 1] means first and second + elements of the vertices list) + - a list of the faces (indices of the vertices in a given face) + + - connectivity information (eventually will be calculated given the verts, + edges, and faces) + ''' + + def __init__(self, *args, **kwargs): + self.vertices = kwargs['vertices'] + self.edges = kwargs['edges'] + self.faces = kwargs['faces'] + + # the strategy for the following members involves lazy-instantiating + # them if they weren't passing them in: + self._faces_for_edge = kwargs.get('faces for edge', None) + self._edges_for_face = kwargs.get('edges for face', None) + self._edges_for_vert = kwargs.get('edges for vert', None) + self._faces_for_vert = kwargs.get('faces for vert', None) + + @property + def faces_for_edge(self): + """returns a list of face indices for a given edge index. + + Intended to be used in the following way: + + >>> # vs, es, fs, ffe, eff, efv, ffv from blender or similar + >>> mesh = Polygon(vs, es, fs, ffe, eff, efv, ffv) + >>> mesh.faces_for_edge[0] + [0, 1] + >>> [self.face[i] for i in mesh.faces_for_edge[1]] + [, ] + + where 0 and 1 are indices into the face list + """ + if self._faces_for_edge is None: + # TODO: eventually support generating this ourselves ... + raise AttributeError("Not yet implemented if you don't explicitly pass this in") + return self._faces_for_edge + + @property + def edges_for_face(self): + """returns a list of edge indices for a given face index.""" + if self._edges_for_face is None: + # TODO: eventually support generating this ourselves ... + raise AttributeError("Not yet implemented if you don't explicitly pass this in") + return self._edges_for_face + + @property + def edges_for_vert(self): + """returns a list of edge indices for a given vertex index.""" + if self._edges_for_vert is None: + # TODO: eventually support generating this ourselves ... + raise AttributeError("Not yet implemented if you don't explicitly pass this in") + return self._edges_for_vert + + @property + def faces_for_vert(self): + """returns a list of face indices for a given vert index.""" + if self._faces_for_vert is None: + # TODO: eventually support generating this ourselves ... + raise AttributeError("Not yet implemented if you don't explicitly pass this in") + return self._faces_for_vert - def edge_ids_with_parent(self, parent_edge_id): - child_edge_ids = [] - for edge in self.edges: - if edge.parent_id == parent_edge_id: - child_edge_ids.append(edge.id) - return child_edge_ids - def __unicode__(self): + # TODO: perhaps also add connectivity here? d = { 'vertices': self.vertices, 'edges': self.edges, 'faces': self.faces, } return pprint.pformat(d) - + __str__ = __unicode__ __repr__ = __unicode__ -