model-converter-python/d3/model/obj.py

#!/usr/bin/env python3

from .basemodel import ModelParser, Exporter, Vertex, TexCoord, Normal, FaceVertex, Face
from .mesh import Material, MeshPart
from functools import reduce
import os.path
import PIL.Image


def is_obj(filename):
    return filename[-4:] == '.obj'

class OBJParser(ModelParser):

    def __init__(self):
        super().__init__()
        self.current_material = None

    def parse_line(self, string):
        if string == '':
            return

        split = string.split()
        first = split[0]
        split = split[1:]

        if first == 'usemtl':
            self.current_material = self.mtl[split[0]]
        elif first == 'mtllib':
            path = os.path.join(os.path.dirname(self.path), split[0])
            self.mtl = MTLParser(self)
            self.mtl.parse_file(path)
        elif first == 'v':
            self.add_vertex(Vertex().from_array(split))
        elif first == 'vn':
            self.add_normal(Normal().from_array(split))
        elif first == 'vt':
            self.add_tex_coord(TexCoord().from_array(split))
        elif first == 'f':
            splits = list(map(lambda x: x.split('/'), split))

            for i in range(len(splits)):
                for j in range(len(splits[i])):
                    if splits[i][j] is not '':
                        splits[i][j] = int(splits[i][j]) - 1

            face = Face().from_array(splits)
            face.material = self.current_material
            self.add_face(face)

class MTLParser:

    def __init__(self, parent):
        self.parent = parent
        self.materials = []
        self.current_mtl = None

    def parse_line(self, string):

        if string == '':
            return

        split = string.split()
        first = split[0]
        split = split[1:]

        if first == 'newmtl':
            self.current_mtl = Material(split[0])
            self.materials.append(self.current_mtl)
        elif first == 'Ka':
            self.current_mtl.Ka = Vertex().from_array(split)
        elif first == 'Kd':
            self.current_mtl.Kd = Vertex().from_array(split)
        elif first == 'Ks':
            self.current_mtl.Ks = Vertex().from_array(split)
        elif first == 'map_Kd':
            self.current_mtl.map_Kd = PIL.Image.open(os.path.join(os.path.dirname(self.parent.path), split[0]))


    def parse_file(self, path):
        with open(path) as f:
            for line in f.readlines():
                line = line.rstrip()
                self.parse_line(line)

    def __getitem__(self, key):
        for material in self.materials:
            if material.name == key:
                return material


class OBJExporter(Exporter):
    def __init__(self, model):
        super().__init__(model)

    def __str__(self):
        string = ""

        for vertex in self.model.vertices:
            string += "v " + ' '.join([str(vertex.x), str(vertex.y), str(vertex.z)]) + "\n"

        string += "\n"

        if len(self.model.tex_coords) > 0:
            for tex_coord in self.model.tex_coords:
                string += "vt " + ' '.join([str(tex_coord.x), str(tex_coord.y)]) + "\n"

            string += "\n"

        if len(self.model.normals) > 0:
            for normal in self.model.normals:
                string += "vn " + ' '.join([str(normal.x), str(normal.y), str(normal.z)]) + "\n"

            string += "\n"

        for face in self.model.faces:
            string += "f "
            arr = []
            for v in [face.a, face.b, face.c]:
                sub_arr = []
                sub_arr.append(str(v.vertex + 1))
                if v.normal is None:
                    if v.texture is not None:
                        sub_arr.append('')
                        sub_arr.append(str(v.texture + 1))
                elif v.texture is not None:
                    sub_arr.append(str(v.texture + 1))
                    if v.normal is not None:
                        sub_arr.append(str(v.normal + 1))
                arr.append('/'.join(sub_arr))

            string += ' '.join(arr) + '\n'
        return string