diff --git a/overviewer.py b/overviewer.py
index 5206ef7..896e955 100755
--- a/overviewer.py
+++ b/overviewer.py
@@ -404,11 +404,12 @@ dir but you forgot to put quotes around the directory, since it contains spaces.
         render = render_things[render_name]
         logging.debug("Found the following render thing: %r", render)
 
-        w = world.World(render['worldpath'])
+        # XXX we now construct the regionset directly
+        #w = world.World(render['worldpath'])
 
         # if no dimension has been specified, just use the first one
         # TODO support the case where a different dimension is specified
-        rset = w.get_regionset(0)
+        rset = world.RegionSet(render['worldpath'])
         logging.debug("Using RegionSet %r", rset) 
 
         # create our TileSet from this RegionSet
diff --git a/overviewer_core/configParser.py b/overviewer_core/configParser.py
index fe2bbfd..b60d091 100644
--- a/overviewer_core/configParser.py
+++ b/overviewer_core/configParser.py
@@ -221,7 +221,7 @@ class MultiWorldParser(object):
         self.settings_file = settings
 
     def parse(self):
-        glob = dict(render=dict(), custom_rendermodes=dict())
+        glob = dict(render=dict(), custom_rendermodes=dict(), world=dict())
 
         try:
             execfile(self.settings_file, glob, glob)    
@@ -243,10 +243,12 @@ class MultiWorldParser(object):
 
         self.render = glob['render']
         self.custom_rendermodes = glob['custom_rendermodes']
+        self.world = glob['world']
 
         # anything that's not 'render' or 'custom_rendermode' is a default
         del glob['render']
         del glob['custom_rendermodes']
+        del glob['world']
 
         # seed with the Overviewer defaults, then update with the user defaults
         self.defaults = dict()
@@ -261,6 +263,11 @@ class MultiWorldParser(object):
 
     def validate(self):
 
+        # first validate the world dict
+        for worldname in self.world:
+            if not os.path.exists(self.world[worldname]):
+                raise Exception("%r does not exist for %s" % (self.world[worldname], worldname))
+
 
         for worldname in self.render:
             world = dict()
@@ -274,10 +281,10 @@ class MultiWorldParser(object):
                
                 definition = settingsDefinition.render[key]
                 try:
-                    val = definition['validator'](world[key])
+                    val = definition['validator'](world[key], world = self.world)
                     world[key] = val
                 except Exception as e:
-                    #print "Error validating %s: %r" % (key, e)
+                    print "Error validating %s: %r" % (key, e)
                     raise e
             self.render[worldname] = world
 
diff --git a/overviewer_core/settingsDefinition.py b/overviewer_core/settingsDefinition.py
index b80f1aa..9a873c0 100644
--- a/overviewer_core/settingsDefinition.py
+++ b/overviewer_core/settingsDefinition.py
@@ -17,19 +17,19 @@ from settingsValidators import *
 # note that all defaults go thought the validator
 
 render = {
-    "worldpath": dict(required=True, validator=validateWorldPath),
+    "worldname": dict(required=True, validator=validateWorldPath),
     "rendermode": dict(required=False, validator=validateRenderMode),
     "northdirection": dict(required=False, validator=validateNorthDirection),
     "renderrange": dict(required=False, validator=validateRenderRange),
-    "forcerender": dict(required=False, validator=bool),
+    "forcerender": dict(required=False, validator=validateBool),
     "stochasticrender": dict(required=False, validator=validateStochastic),
     "imgformat": dict(required=False, validator=validateImgFormat, default="png"),
     "imgquality": dict(required=False, validator=validateImgQuality),
     "bgcolor": dict(required=False, validator=validateBGColor, default="1a1a1a"),
     "optimizeimg": dict(required=False, validator=validateOptImg, default=0),
-    "nomarkers": dict(required=False, validator=bool),
+    "nomarkers": dict(required=False, validator=validateBool),
     "texturepath": dict(required=False, validator=validateTexturePath),
-    "renderchecks": dict(required=False, validator=int, default=0),
-    "rerenderprob": dict(required=False, validator=float, default=0),
+    "renderchecks": dict(required=False, validator=validateInt, default=0),
+    "rerenderprob": dict(required=False, validator=validateFloat, default=0),
     }
 
diff --git a/overviewer_core/settingsValidators.py b/overviewer_core/settingsValidators.py
index 1fcf8ca..dd398d2 100644
--- a/overviewer_core/settingsValidators.py
+++ b/overviewer_core/settingsValidators.py
@@ -5,25 +5,19 @@ import os.path
 class ValidationException(Exception):
     pass
 
-def validateWorldPath(path):
-    try:
-        if not os.path.exists(path):
-            raise ValidationException("%r does not exist" % path)
-        if not os.path.isdir(path):
-            raise ValidationException("%r is not a directory" % path)
-    except ValidationException, e:
-        # TODO assume this is the name of a world and try
-        # to find it
-        raise e
-    full_path = os.path.abspath(path)
-    return full_path
+def validateWorldPath(name, **kwargs):
+    world = kwargs.get('world', dict())
+    if name not in world.keys():
+        raise ValidationException("bad world name")
+    return os.path.abspath(world[name])
 
-def validateRenderMode(mode):
+
+def validateRenderMode(mode, **kwargs):
     # TODO get list of valid rendermodes
     #raise NotImplementedError("validateRenderMode")
     return mode
 
-def validateNorthDirection(direction):
+def validateNorthDirection(direction, **kwargs):
     # normalize to integers
     intdir = 0 #default
     if type(direction) == int:
@@ -37,28 +31,28 @@ def validateNorthDirection(direction):
         raise ValidationException("%r is not a valid north direction" % direction)
     return intdir
 
-def validateRenderRange(r):
+def validateRenderRange(r, **kwargs):
     raise NotImplementedError("render range")
 
-def validateStochastic(s):
+def validateStochastic(s, **kwargs):
     val = float(s)
     if val < 0 or val > 1:
         raise ValidationException("%r is not a valid stochastic value.  Should be between 0.0 and 1.0" % s)
     return val
 
-def validateImgFormat(fmt):
+def validateImgFormat(fmt, **kwargs):
     if fmt not in ("png", "jpg", "jpeg"):
         raise ValidationException("%r is not a valid image format" % fmt)
     if fmt == "jpeg": fmt = "jpg"
     return fmt
 
-def validateImgQuality(qual):
+def validateImgQuality(qual, **kwargs):
     intqual = int(qual)
     if (intqual < 0 or intqual > 100):
         raise ValidationException("%r is not a valid image quality" % intqual)
     return intqual
 
-def validateBGColor(color):
+def validateBGColor(color, **kwargs):
     """BG color must be an HTML color, with an option leading # (hash symbol)
     returns an (r,b,g) 3-tuple  
     """
@@ -80,11 +74,20 @@ def validateBGColor(color):
         return color
 
 
-def validateOptImg(opt):
+def validateOptImg(opt, **kwargs):
     return bool(opt)
 
-def validateTexturePath(path):
+def validateTexturePath(path, **kwargs):
     # Expand user dir in directories strings
     path = os.path.expanduser(path)
     # TODO assert this path exists?
 
+
+def validateBool(b, **kwargs):
+    return bool(b)
+
+def validateFloat(f, **kwargs):
+    return float(f)
+
+def validateInt(i, **kwargs):
+    return int(i)
diff --git a/overviewer_core/world.py b/overviewer_core/world.py
index ebe6485..56b552d 100644
--- a/overviewer_core/world.py
+++ b/overviewer_core/world.py
@@ -194,8 +194,8 @@ we're reading from. There is one of these per set of regions on the hard drive,
 but may be several per invocation of the Overviewer in the case of multi-world.
     """
 
-    def __init__(self, worldobj, regiondir):
-        self.world = worldobj
+    def __init__(self, regiondir):
+        #self.world = worldobj
         self.regiondir = regiondir
 
         logging.info("Scanning regions")
diff --git a/test/data/settings/settings_test_1.py b/test/data/settings/settings_test_1.py
index 370e3d6..5aa7b77 100644
--- a/test/data/settings/settings_test_1.py
+++ b/test/data/settings/settings_test_1.py
@@ -1,4 +1,6 @@
-worldpath="test/data/settings/test_world"
+world['test'] = "test/data/settings/test_world"
+worldname = 'test'
+
 rendermode = "normal"
 
 render["world"] = { 
diff --git a/test/data/settings/settings_test_bgcolor.py b/test/data/settings/settings_test_bgcolor.py
index a14d5bc..08cc1d9 100644
--- a/test/data/settings/settings_test_bgcolor.py
+++ b/test/data/settings/settings_test_bgcolor.py
@@ -1,6 +1,8 @@
 bgcolor="#000000"
 
+world['test'] = "test/data/settings/test_world"
+
 render["world"] = { 
-    "worldpath": "test/data/settings/test_world", 
+    "worldname": "test", 
     "bgcolor":"ffff"
 }
diff --git a/test/data/settings/settings_test_rendermode.py b/test/data/settings/settings_test_rendermode.py
index 5c28040..b0d205a 100644
--- a/test/data/settings/settings_test_rendermode.py
+++ b/test/data/settings/settings_test_rendermode.py
@@ -1,5 +1,7 @@
+world['test'] = "test/data/settings/test_world"
+
 render["world"] = { 
-    "worldpath": "test/data/settings/test_world", 
+    "worldname": "test", 
     "rendermode": "bad_rendermode",
     "northdirection": ["upper-left"],
 }