import_raw.py

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# <pep8-80 compliant>

"""
This script imports Raw Triangle File format files to Blender.

The raw triangle format is very simple; it has no verts or faces lists.
It's just a simple ascii text file with the vertices of each triangle
listed on each line. In addition, a line with 12 values will be
imported as a quad. This may be in conflict with some other
applications, which use a raw format, but this is how it was
implemented back in blender 2.42.

Usage:
Execute this script from the "File->Import" menu and choose a Raw file to
open.

Notes:
Generates the standard verts and faces lists, but without duplicate
verts. Only *exact* duplicates are removed, there is no way to specify a
tolerance.
"""


import bpy


def readMesh(filename, objName):
    filehandle = open(filename, "rb")

    def line_to_face(line):
        # Each triplet is an xyz float
        line_split = line.split()
        try:
            line_split_float = map(float, line_split)
        except:
            return None

        if len(line_split) in {9, 12}:
            return zip(*[iter(line_split_float)] * 3)  # group in 3's
        else:
            return None

    faces = []
    for line in filehandle.readlines():
        face = line_to_face(line)
        if face:
            faces.append(face)

    filehandle.close()

    # Generate verts and faces lists, without duplicates
    verts = []
    coords = {}
    index_tot = 0
    faces_indices = []

    for f in faces:
        fi = []
        for i, v in enumerate(f):
            index = coords.get(v)

            if index is None:
                index = coords[v] = index_tot
                index_tot += 1
                verts.append(v)

            fi.append(index)

        faces_indices.append(fi)

    mesh = bpy.data.meshes.new(objName)
    mesh.from_pydata(verts, [], faces_indices)

    return mesh


def addMeshObj(mesh, objName):
    scn = bpy.context.scene

    for o in scn.objects:
        o.select = False

    mesh.update()
    mesh.validate()

    nobj = bpy.data.objects.new(objName, mesh)
    scn.objects.link(nobj)
    nobj.select = True

    if scn.objects.active is None or scn.objects.active.mode == 'OBJECT':
        scn.objects.active = nobj


def read(filepath):
    #convert the filename to an object name
    objName = bpy.path.display_name_from_filepath(filepath)
    mesh = readMesh(filepath, objName)
    addMeshObj(mesh, objName)