bin.py

import bpy
import mathutils
import re
import os
import struct
import meshio
from math import radians

def readBIN_to_meshio(filepath):
    firstFile = open(filepath, 'rb')

    # read number of bodies
    bytes = firstFile.read()
    firstFile.close()

    isFirstFile = ((len(bytes) % 48) != 0)

    # currently assume that numBodies is always 1
    (numBodies,), bytes = struct.unpack('i', bytes[:4]), bytes[4:]
    numBodies *= isFirstFile

    field_datas = []
    for i in range(0, numBodies):
        # determine length of file name string
        (strLength,), bytes = struct.unpack('i', bytes[:4]), bytes[4:]
        
        # read file name
        objFile, bytes = bytes[:strLength], bytes[strLength:]
        if i == 0:
            objFileString = objFile.decode('ascii')

        cur_field_data = {}
        cur_field_data["translation"] = None
        cur_field_data["scaling"] = None
        cur_field_data["rotation"] = None
        cur_field_data["transformation_matrix"] = None

        # Read scaling factors in first file
        (sx,), bytes = struct.unpack('f', bytes[:4]), bytes[4:]
        (sy,), bytes = struct.unpack('f', bytes[:4]), bytes[4:]
        (sz,), bytes = struct.unpack('f', bytes[:4]), bytes[4:]

        cur_field_data["scaling"] = (sx, sy, sz)

        (isWall,), bytes = struct.unpack('?', bytes[:1]), bytes[1:]
        (colr,), bytes = struct.unpack('f', bytes[:4]), bytes[4:]
        (colg,), bytes = struct.unpack('f', bytes[:4]), bytes[4:]
        (colb,), bytes = struct.unpack('f', bytes[:4]), bytes[4:]
        (cola,), bytes = struct.unpack('f', bytes[:4]), bytes[4:]

        field_datas.append(cur_field_data)

    # if the object name is empty, then we know that it is not a "first file"
    # and we just simply reopen it and start from the beginning
    if isFirstFile:
        # create mesh from referenced object
        dirPath = os.path.dirname(filepath)
        objPath = os.path.join(dirPath, objFileString)

        mesh = meshio.read(objPath)
    else:
        otherFile = open(filepath, 'rb')

        # reopen same file
        bytes = otherFile.read()
        otherFile.close()

        # since there is no object referenced, create empty mesh
        mesh = meshio.Mesh([], [])

    i = 0
    while len(bytes) != 0:
        cur_field_data = {}
        cur_field_data["translation"] = None
        cur_field_data["scaling"] = (1, 1, 1)
        cur_field_data["rotation"] = None
        cur_field_data["transformation_matrix"] = None

        # Read translation in first file
        (x,), bytes = struct.unpack('f', bytes[:4]), bytes[4:]
        (y,), bytes = struct.unpack('f', bytes[:4]), bytes[4:]
        (z,), bytes = struct.unpack('f', bytes[:4]), bytes[4:]

        cur_field_data["translation"] = (x, y, z)

        # Read rotation in first file
        r = []
        for _ in range(0,9):
            (value,), bytes = struct.unpack('f', bytes[:4]), bytes[4:]
            r.append(value)

        rotationMatrix = mathutils.Matrix()
        rotationMatrix[0][0:3] = r[0], r[3], r[6]
        rotationMatrix[1][0:3] = r[1], r[4], r[7]
        rotationMatrix[2][0:3] = r[2], r[5], r[8]

        cur_field_data["rotation"] = rotationMatrix.to_quaternion()
        cur_field_data["transformation_matrix"] = mathutils.Matrix.LocRotScale(
                                                    cur_field_data["translation"], 
                                                    cur_field_data["rotation"], 
                                                    cur_field_data["scaling"])

        if isFirstFile:
            field_datas[i]["translation"] = cur_field_data["translation"]
            field_datas[i]["rotation"] = cur_field_data["rotation"]
            field_datas[i]["transformation_matrix"] = cur_field_data["transformation_matrix"]
        else:
            field_datas.append(cur_field_data)

        i += 1

    mesh.field_data = field_datas[0]

    return mesh

# no need for write function
meshio.register_format("bin", [".bin"], readBIN_to_meshio, {".bin": None})