148 lines
4.7 KiB
Python
148 lines
4.7 KiB
Python
class MeshData(object):
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def __init__(self, **kwargs):
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self.name = kwargs.get("name")
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self.vertex_format = [
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(b'v_pos', 3, 'float'),
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(b'v_normal', 3, 'float'),
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(b'v_tc0', 2, 'float')]
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self.vertices = []
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self.indices = []
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def calculate_normals(self):
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for i in range(len(self.indices) / (3)):
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fi = i * 3
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v1i = self.indices[fi]
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v2i = self.indices[fi + 1]
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v3i = self.indices[fi + 2]
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vs = self.vertices
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p1 = [vs[v1i + c] for c in range(3)]
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p2 = [vs[v2i + c] for c in range(3)]
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p3 = [vs[v3i + c] for c in range(3)]
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u, v = [0, 0, 0], [0, 0, 0]
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for j in range(3):
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v[j] = p2[j] - p1[j]
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u[j] = p3[j] - p1[j]
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n = [0, 0, 0]
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n[0] = u[1] * v[2] - u[2] * v[1]
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n[1] = u[2] * v[0] - u[0] * v[2]
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n[2] = u[0] * v[1] - u[1] * v[0]
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for k in range(3):
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self.vertices[v1i + 3 + k] = n[k]
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self.vertices[v2i + 3 + k] = n[k]
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self.vertices[v3i + 3 + k] = n[k]
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class ObjFile:
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def finish_object(self):
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if self._current_object is None:
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return
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mesh = MeshData()
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idx = 0
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for f in self.faces:
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verts = f[0]
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norms = f[1]
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tcs = f[2]
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for i in range(3):
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# get normal components
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n = (0.0, 0.0, 0.0)
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if norms[i] != -1:
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n = self.normals[norms[i] - 1]
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# get texture coordinate components
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t = (0.0, 0.0)
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if tcs[i] != -1:
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t = self.texcoords[tcs[i] - 1]
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# get vertex components
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v = self.vertices[verts[i] - 1]
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data = [v[0], v[1], v[2], n[0], n[1], n[2], t[0], t[1]]
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mesh.vertices.extend(data)
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tri = [idx, idx + 1, idx + 2]
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mesh.indices.extend(tri)
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idx += 3
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self.objects[self._current_object] = mesh
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# mesh.calculate_normals()
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self.faces = []
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def __init__(self, filename, swapyz=False):
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"""Loads a Wavefront OBJ file. """
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self.objects = {}
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self.vertices = []
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self.normals = []
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self.texcoords = []
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self.faces = []
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self._current_object = None
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material = None
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for line in open(filename, "r"):
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if line.startswith('#'):
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continue
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if line.startswith('s'):
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continue
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values = line.split()
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if not values:
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continue
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if values[0] == 'o':
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self.finish_object()
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self._current_object = values[1]
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# elif values[0] == 'mtllib':
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# self.mtl = MTL(values[1])
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# elif values[0] in ('usemtl', 'usemat'):
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# material = values[1]
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if values[0] == 'v':
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v = list(map(float, values[1:4]))
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if swapyz:
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v = v[0], v[2], v[1]
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self.vertices.append(v)
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elif values[0] == 'vn':
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v = list(map(float, values[1:4]))
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if swapyz:
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v = v[0], v[2], v[1]
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self.normals.append(v)
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elif values[0] == 'vt':
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self.texcoords.append(list(map(float, values[1:3])))
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elif values[0] == 'f':
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face = []
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texcoords = []
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norms = []
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for v in values[1:]:
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w = v.split('/')
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face.append(int(w[0]))
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if len(w) >= 2 and len(w[1]) > 0:
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texcoords.append(int(w[1]))
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else:
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texcoords.append(-1)
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if len(w) >= 3 and len(w[2]) > 0:
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norms.append(int(w[2]))
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else:
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norms.append(-1)
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self.faces.append((face, norms, texcoords, material))
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self.finish_object()
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def MTL(filename):
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contents = {}
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mtl = None
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return
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for line in open(filename, "r"):
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if line.startswith('#'):
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continue
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values = line.split()
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if not values:
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continue
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if values[0] == 'newmtl':
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mtl = contents[values[1]] = {}
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elif mtl is None:
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raise ValueError("mtl file doesn't start with newmtl stmt")
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mtl[values[0]] = values[1:]
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return contents
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