diff --git a/korman/exporter/mesh.py b/korman/exporter/mesh.py
index bb41ae1..2f01b1f 100644
--- a/korman/exporter/mesh.py
+++ b/korman/exporter/mesh.py
@@ -302,10 +302,11 @@ class MeshConverter:
                    "screen": bpy.context.screen,
                    "window": bpy.context.window}
 
-        if bo.plasma_modifiers.lightmap.enabled:
+        lm = bo.plasma_modifiers.lightmap
+        if lm.enabled:
             print("    Baking lightmap...")
             print("====")
-            bpy.ops.object.plasma_lightmap_autobake(context)
+            bpy.ops.object.plasma_lightmap_autobake(context, light_group=lm.light_group)
             print("====")
         else:
             for vcol_layer in bo.data.vertex_colors:
diff --git a/korman/operators/op_lightmap.py b/korman/operators/op_lightmap.py
index dcb704b..7f6b09f 100644
--- a/korman/operators/op_lightmap.py
+++ b/korman/operators/op_lightmap.py
@@ -14,6 +14,7 @@
 #    along with Korman.  If not, see <http://www.gnu.org/licenses/>.
 
 import bpy
+from bpy.props import *
 from ..helpers import GoodNeighbor
 
 def _fetch_lamp_objects():
@@ -37,26 +38,30 @@ class _LightingOperator:
         toggle.track(render, "use_raytrace", True)
         toggle.track(render, "bake_type", "FULL")
 
-    def _generate_lightgroups(self, mesh):
+    def _generate_lightgroups(self, mesh, user_lg=None):
         """Makes a new light group for the baking process that excludes all Plasma RT lamps"""
-        shouldibake = False
+        shouldibake = (user_lg and user_lg.objects)
 
         for material in mesh.materials:
             lg = material.light_group
             self._old_lightgroups[material] = lg
 
-            # TODO: faux-lightgroup caching for the entire export process. you dig?
-            if lg is None or len(lg.objects) == 0:
-                source = _fetch_lamp_objects()
+            if user_lg is None:
+                # TODO: faux-lightgroup caching for the entire export process. you dig?
+                if not lg or len(lg.objects) == 0:
+                    source = _fetch_lamp_objects()
+                else:
+                    source = lg.objects
+                dest = bpy.data.groups.new("_LIGHTMAPGEN_{}".format(material.name))
+
+                # Only use non-RT lights
+                for obj in source:
+                    if obj.plasma_object.enabled:
+                        continue
+                    dest.objects.link(obj)
+                    shouldibake = True
             else:
-                source = lg.objects
-            dest = bpy.data.groups.new("_LIGHTMAPGEN_{}".format(material.name))
-    
-            for obj in source:
-                if obj.plasma_object.enabled:
-                    continue
-                dest.objects.link(obj)
-                shouldibake = True
+                dest = user_lg
             material.light_group = dest
         return shouldibake
 
@@ -77,6 +82,8 @@ class LightmapAutobakeOperator(_LightingOperator, bpy.types.Operator):
     bl_label = "Bake Lightmap"
     bl_options = {"INTERNAL"}
 
+    light_group = StringProperty(name="Light Group")
+
     def __init__(self):
         super().__init__()
 
@@ -135,7 +142,8 @@ class LightmapAutobakeOperator(_LightingOperator, bpy.types.Operator):
             self._apply_render_settings(render, toggle)
 
             # Now, we *finally* bake the lightmap...
-            if self._generate_lightgroups(mesh):
+            light_group = bpy.data.groups[self.light_group] if self.light_group else None
+            if self._generate_lightgroups(mesh, light_group):
                 bpy.ops.object.bake_image()
                 im.pack(as_png=True)
             self._pop_lightgroups()
@@ -149,11 +157,13 @@ class LightmapAutobakePreviewOperator(_LightingOperator, bpy.types.Operator):
     bl_label = "Preview Lightmap"
     bl_options = {"INTERNAL"}
 
+    light_group = StringProperty(name="Light Group")
+
     def __init__(self):
         super().__init__()
 
     def execute(self, context):
-        bpy.ops.object.plasma_lightmap_autobake()
+        bpy.ops.object.plasma_lightmap_autobake(light_group=self.light_group)
 
         tex = bpy.data.textures.get("LIGHTMAPGEN_PREVIEW")
         if tex is None:
diff --git a/korman/properties/modifiers/render.py b/korman/properties/modifiers/render.py
index bfdc0b6..daf4975 100644
--- a/korman/properties/modifiers/render.py
+++ b/korman/properties/modifiers/render.py
@@ -36,6 +36,9 @@ class PlasmaLightMapGen(PlasmaModifierProperties):
                                   ("1024", "1024px", "1024x1024 pixels"),
                             ])
 
+    light_group = StringProperty(name="Light Group",
+                                 description="Group that defines the collection of lights to bake")
+
     def created(self, obj):
         self.display_name = "{}_LIGHTMAPGEN".format(obj.name)
 
diff --git a/korman/ui/modifiers/render.py b/korman/ui/modifiers/render.py
index ac4936e..de88b96 100644
--- a/korman/ui/modifiers/render.py
+++ b/korman/ui/modifiers/render.py
@@ -16,9 +16,10 @@
 import bpy
 
 def lightmap(modifier, layout, context):
-    col = layout.column(align=True)
-    col.row(align=True).prop(modifier, "quality", expand=True)
-    col.operator("object.plasma_lightmap_preview", "Preview Lightmap", icon="RENDER_STILL")
+    layout.row(align=True).prop(modifier, "quality", expand=True)
+    layout.prop_search(modifier, "light_group", bpy.data, "groups", icon="GROUP")
+    operator = layout.operator("object.plasma_lightmap_preview", "Preview Lightmap", icon="RENDER_STILL")
+    operator.light_group = modifier.light_group
 
     # Kind of clever stuff to show the user a preview...
     # We can't show images, so we make a hidden ImageTexture called LIGHTMAPGEN_PREVIEW. We check