Dump Blender Scene as Lua via Introspection

io_export_lua.py

bl_info = {
	"name": "Export Scene as Lua (.lua)",
	"author": "John Connors (ZabaQ)",
	"version": (0, 7),
	"blender": (2, 5, 4),
	"api": 33047,
	"location": "File > Export",
	"description": "Blender Scene To Lua (.lua)",
	"warning": "",
	"category": "Import-Export"}



import bpy
import mathutils
import types
# ExportHelper is a helper class, defines filename and
# invoke() function which calls the file selector.
from bpy_extras.io_utils import ExportHelper
from bpy.props import StringProperty, BoolProperty, EnumProperty

# transform python property to lua id
def luaify(s):
	if ((s == None) or (s[-1:]==']')):
		return None
	result = s.split('.')[-1:]
	result = result[0].lower()
	return result

def escape_lua_string(s):
	broken = s.split("\\")
	return "\\\\".join(broken)

def introspect_obj(o, txt, indent = 4):
	global annotate_file
	global outfile
	type_o = type(o)
	# it has a key associated with it
	if (txt != None):
		luaname = luaify(txt)
		if (luaname != None):
			if annotate_file:
				print("", file=outfile)
				print(" " * indent, end='', file=outfile)
				print ( "--[[ " + txt + " " + str(type_o) + "]] ", end = '', file=outfile)		
			print("", file=outfile)
			print(" " * indent, end='', file=outfile)
			print (  luaname + " = ", end = '', file=outfile )
	# not interested in functions
	if (type_o in [ types.CodeType, types.BuiltinFunctionType, types.BuiltinMethodType, types.FunctionType, types.LambdaType, types.MethodType ]):
		print ("nil ", end = '', file=outfile)
		return
	if (str(type_o) == "<class 'bpy_func'>"): # must be a better way to do this
		print ("nil ", end = '', file=outfile)
		return
	# now for the value
	# boolean
	if (type_o == bool):
		if (o == False):
			print("false ", end = '', file=outfile)
		else:
			print("true ", end = '', file=outfile)
		return
	# None
	if (o == None):
		print ("nil ", end = '', file=outfile)
		return
	# Numeric
	if (type_o in [ int, float ]):
		print(o, " ", end='', file=outfile)
		return
	# string
	if (issubclass(type_o, str)):
		print ("\"" + escape_lua_string(o) + "\" ", file=outfile, end='')
		return
	if txt == None:
		return
	# we do this explicitly to avoid the madness of swizzling (100s of members per vector!)
	if (type_o == mathutils.Vector):
		items = [ 'x', 'y', 'z', 'w' ]
		print( " { ", end = '' , file=outfile)
		for item in items:
			newtxt = txt + '.' + item
			val = getattr(o, item, None)
			if (val != None):
				print(" ", end='', file=outfile)
				introspect_obj( val, newtxt, indent + 4 )
				print(" , ", end='', file=outfile)				
		print( " } --[[ vec ]] ", end = '' , file=outfile)
		return
	# object members
	try: __members__ = dir(o)
	except: __members__ = []
	# all kinds of stuff turns up in dir(), so filter it out
	if (__members__ != []):
		fields = []
		for item in __members__:
			# internal data
			if item.startswith("__"):
				continue
			# Blenders own type system gets in the way
			if item in [ 'rna_type', 'bl_rna', 'owner' ]:
				continue
			if item in txt:
				continue
			# we want data, not funcitions
			type_i = type(getattr(o, item, None))
			if (type_i in [ types.CodeType, types.BuiltinFunctionType, types.BuiltinMethodType, types.FunctionType, types.LambdaType ]):
				continue
			if (str(type_i) == "<class 'bpy_func'>"): # must be a better way to do this
				continue
			fields += [ item ]
		# if there's anything left, print it
		if (len(fields) != 0):
			print("", end = '', file=outfile)
			print(" " * indent, end='', file=outfile)
			print("{", end = '' , file=outfile)
			itemindex = 0
			fi = len(fields)
			for item in fields:
				newtxt = txt + '.' + item
#   			print(" -- %s " % newtxt, end='', file=outfile)
				itemindex = itemindex + 1
				introspect_obj( getattr(o, item, None), newtxt, indent + 4)
				fi = fi - 1
				if (fi > 0):
					print(" , ", end='', file=outfile)
			print( " } --[[ fields ]] ", end='', file=outfile)
			return
	# now, try dict types
	try: keys = o.keys()
	except: keys = None
	if keys:
		print( "{", end = '' , file=outfile)
		ik = len(keys)
		for k in keys:
			newtxt = txt + "[" + k + "]"
			ik = ik - 1
			type_i = type(o.__getitem__(k))
			print(" %s = " % k, end='', file=outfile)
			introspect_obj(o.__getitem__(k), newtxt, indent+4)
			if (ik > 0):
				print(" , ", end='', file=outfile)
		print( " } --[[ keys ]] ", end='', file=outfile)
	else:
		# list/tuple
		try: length = len( o )
		except: length = -1
		if (length != -1):
			# indexable?
			if ("__getitem__" in __members__):
				# print(" " * indent, end='', file=outfile)
				# print(txt)
				# lets not dump entire textures > 4k in ascii, m'kay :-)
				print( " { ", end = '' , file=outfile)				
				if (not("pixels" in txt) or (length < 4 * 1024)):
					for i in range(length):
						print(" ", end='', file=outfile)
						newtxt = txt + '[' + str(i) + ']'
#						print(" -- %s " % newtxt, end='', file=outfile)
						print(" [%d] = " % i, end='', file=outfile)
						introspect_obj(o[i], newtxt, indent+4)
						if (i < length -1):
							print(" , ", end='', file=outfile)
				print( " } --[[ array ]]  " , end = '', file=outfile)
			else:
				# sets/nonindexable
				# print(" " * indent, end='', file=outfile)
				print( " { ", end = '' , file=outfile)
				ic = len(o)
				for i in o:
					introspect_obj(i, None, indent+4)
					ic = ic - 1
					if (ic > 0):
						print(" , ", end='', file=outfile)
				print( " } --[[ set ]] ", end='', file=outfile)
	return


def dump_lua(fn, package, introspect, annotate):
	global outfile
	global annotate_file
	outfile = open(fn, 'w+')
	print ("%s =  {" % package, end='', file=outfile)
	annotate_file = annotate
	introspect_obj(eval(introspect, globals(), locals()), introspect)
	print ("}", file=outfile)
	outfile.close()

class Export_Lua(bpy.types.Operator, ExportHelper):
	'''Export secene as structured Lua Table'''
	bl_idname = "export.lua"
	bl_label = "Export Lua"
	filename_ext = ".lua"

	filter_glob = StringProperty(default="*.lua", options={'HIDDEN'})

	filepath = StringProperty(name="File Path", description="Filepath used for exporting the lua file", maxlen= 1024, default= "", subtype='FILE_PATH')
	check_existing = BoolProperty(name="Check Existing", description="Check and warn on overwriting existing files", default=True)
	packageName = StringProperty(name="VarName", description="Name of variable to assign scene to.", maxlen=256,default="scene")
	introspectName = StringProperty(name="Data", description="Data to introspect", maxlen=256, default="bpy.context.active_object")
	annotateFlag = BoolProperty(name="Annotate", description="Annotate file with comments (makes it large!)", default=False)
	@classmethod
	def poll(cls, context):
		return context.active_object != None

	def execute(self, context):
		dump_lua(self.filepath, self.packageName, self.introspectName, self.annotateFlag)
		return {'FINISHED'}


### REGISTER ###

def menu_func(self, context):
	self.layout.operator(Export_Lua.bl_idname, text="Lua (.lua)")


def register():
	bpy.utils.register_class(Export_Lua)
	bpy.types.INFO_MT_file_export.append(menu_func)
	#bpy.types.VIEW3D_PT_tools_objectmode.prepend(menu_func)

def unregister():
	bpy.utils.unregister_class(Export_Lua)
	bpy.types.INFO_MT_file_export.remove(menu_func)


if __name__ == "__main__":
	register()
  # test call
	bpy.ops.export.Lua('INVOKE_DEFAULT')