diff --git a/src/java/com/threerings/miso/client/DisplayMisoSceneImpl.java b/src/java/com/threerings/miso/client/DisplayMisoSceneImpl.java
index d1de99438..d83d6a9c1 100644
--- a/src/java/com/threerings/miso/client/DisplayMisoSceneImpl.java
+++ b/src/java/com/threerings/miso/client/DisplayMisoSceneImpl.java
@@ -1,5 +1,5 @@
 //
-// $Id: DisplayMisoSceneImpl.java,v 1.34 2001/09/21 00:21:40 mdb Exp $
+// $Id: DisplayMisoSceneImpl.java,v 1.35 2001/09/21 02:30:35 mdb Exp $
 
 package com.threerings.miso.scene;
 
@@ -21,32 +21,8 @@ import com.threerings.miso.scene.util.ClusterUtil;
  * screen for game play. For instance, one scene might display a portion
  * of a street with several buildings scattered about on the periphery.
  */
-public class MisoScene implements Scene
+public class MisoSceneImpl implements EditableMisoScene
 {
-    /** The base layer id. */
-    public static final int LAYER_BASE = 0;
-
-    /** The fringe layer id. */
-    public static final int LAYER_FRINGE = 1;
-
-    /** The object layer id. */
-    public static final int LAYER_OBJECT = 2;
-
-    /** The total number of layers. */
-    public static final int NUM_LAYERS = 3;
-
-    /** The latest scene file format version. */
-    public static final short VERSION = 1;
-
-    /** String translations of each tile layer name. */
-    public static final String[] XLATE_LAYERS = { "Base", "Fringe", "Object" };
-
-    /** Scene id to denote an unset or otherwise invalid scene id. */
-    public static final int SID_INVALID = -1;
-
-    /** The tiles comprising the scene. */
-    public Tile tiles[][][];
-
     /**
      * Construct a new miso scene object. The base layer tiles are
      * initialized to contain tiles of the specified default tileset and
@@ -57,8 +33,8 @@ public class MisoScene implements Scene
      * @param deftsid the default tileset id.
      * @param deftid the default tile id.
      */
-    public MisoScene (IsoSceneViewModel model, TileManager tilemgr,
-		      int deftsid, int deftid)
+    public MisoSceneImpl (IsoSceneViewModel model, TileManager tilemgr,
+                          int deftsid, int deftid)
     {
 	_model = model;
 	_tilemgr = tilemgr;
@@ -70,13 +46,13 @@ public class MisoScene implements Scene
 	_clusters = new ArrayList();
         _portals = new ArrayList();
 
-	tiles = new Tile[_model.scenewid][_model.scenehei][NUM_LAYERS];
+	_tiles = new Tile[_model.scenewid][_model.scenehei][NUM_LAYERS];
 	_deftile = _tilemgr.getTile(deftsid, deftid);
 	for (int xx = 0; xx < _model.scenewid; xx++) {
 	    for (int yy = 0; yy < _model.scenehei; yy++) {
 		for (int ii = 0; ii < NUM_LAYERS; ii++) {
 		    if (ii == LAYER_BASE) {
-			tiles[xx][yy][ii] = _deftile;
+			_tiles[xx][yy][ii] = _deftile;
 		    }
 		}
 	    }
@@ -84,7 +60,7 @@ public class MisoScene implements Scene
     }
 
     /**
-     * Construct a new miso scene object with the given values.
+     * Construct a new Miso scene object with the given values.
      *
      * @param model the iso scene view model.
      * @param tilemgr the tile manager.
@@ -93,10 +69,10 @@ public class MisoScene implements Scene
      * @param portals the portals.
      * @param tiles the tiles comprising the scene.
      */
-    public MisoScene (IsoSceneViewModel model, TileManager tilemgr,
-		      String name, ArrayList locations,
-		      ArrayList clusters, ArrayList portals,
-		      Tile tiles[][][])
+    public MisoSceneImpl (IsoSceneViewModel model, TileManager tilemgr,
+                          String name, ArrayList locations,
+                          ArrayList clusters, ArrayList portals,
+                          Tile[][][] tiles)
     {
 	_model = model;
 	_tilemgr = tilemgr;
@@ -105,7 +81,7 @@ public class MisoScene implements Scene
         _locations = locations;
 	_clusters = clusters;
         _portals = portals;
-        this.tiles = tiles;
+        _tiles = tiles;
     }
 
     // documentation inherited
@@ -133,89 +109,60 @@ public class MisoScene implements Scene
         return null;
     }
 
-    /**
-     * Return the default tile for the base layer of the scene.
-     */
+    // documentation inherited
+    public Tile[][][] getTiles ()
+    {
+        return _tiles;
+    }
+
+    // documentation inherited
     public Tile getDefaultTile ()
     {
 	return _deftile;
     }
 
-    /**
-     * Return the scene locations list.
-     */
-    public ArrayList getLocations ()
+    // documentation inherited
+    public Location[] getLocations ()
     {
-        return _locations;
+        Location[] locs = new Location[_locations.size()];
+        _locations.toArray(locs);
+        return locs;
     }
 
-    /**
-     * Return the cluster list.
-     */
-    public ArrayList getClusters ()
+    // documentation inherited
+    public Cluster[] getClusters ()
     {
-	return _clusters;
+        Cluster[] clusters = new Cluster[_clusters.size()];
+        _clusters.toArray(clusters);
+        return clusters;
     }
 
-    /**
-     * Return the scene portals list.
-     */
-    public ArrayList getPortals ()
+    // documentation inherited
+    public Portal[] getPortals ()
     {
-        return _portals;
+        Portal[] portals = new Portal[_portals.size()];
+        _portals.toArray(portals);
+        return portals;
     }
 
-    /**
-     * Set the default entrance portal for this scene.
-     *
-     * @param entrance the entrance portal.
-     */
+    // documentation inherited
+    public Portal getEntrance ()
+    {
+        return _entrance;
+    }
+
+    // documentation inherited
+    public void setName (String name)
+    {
+        _name = name;
+    }
+
+    // documentation inherited
     public void setEntrance (Portal entrance)
     {
 	_entrance = entrance;
     }
 
-    /**
-     * Return the number of clusters in the scene.
-     */
-    public int getNumClusters ()
-    {
-	return _clusters.size();
-    }
-
-    /**
-     * Return the number of actual (non-null) tiles present in the
-     * specified tile layer for this scene.
-     */
-    public int getNumLayerTiles (int lnum)
-    {
-	if (lnum == LAYER_BASE) {
-	    return _model.scenewid * _model.scenehei;
-	}
-
-	int numTiles = 0;
-	for (int xx = 0; xx < _model.scenewid; xx++) {
-	    for (int yy = 0; yy < _model.scenehei; yy++) {
-		if (tiles[xx][yy] != null) {
-		    numTiles++;
-		}
-	    }
-	}
-
-	return numTiles;
-    }
-
-    /**
-     * Return the cluster index number the given location is in, or -1
-     * if the location is not in any cluster.
-     *
-     * @param loc the location.
-     */
-    public int getClusterIndex (Location loc)
-    {
-	return ClusterUtil.getClusterIndex(_clusters, loc);
-    }
-
     /**
      * Update the specified location in the scene.  If the cluster
      * index number is -1, the location will be removed from any
@@ -259,28 +206,9 @@ public class MisoScene implements Scene
     }
 
     /**
-     * Return the location object at the given full coordinates, or
-     * null if no location is currently present at that location.
-     *
-     * @param x the full x-position coordinate.
-     * @param y the full y-position coordinate.
-     *
-     * @return the location object.
-     */
-    public Location getLocation (int x, int y)
-    {
-	int size = _locations.size();
-	for (int ii = 0; ii < size; ii++) {
-	    Location loc = (Location)_locations.get(ii);
-	    if (loc.x == x && loc.y == y) return loc;
-	}
-	return null;
-    }
-
-    /**
-     * Remove the given location object from the location list, and
-     * from any containing cluster.  If the location is a portal, it
-     * is removed from the portal list as well.
+     * Remove the given location object from the location list, and from
+     * any containing cluster.  If the location is a portal, it is removed
+     * from the portal list as well.
      *
      * @param loc the location object.
      */
@@ -301,25 +229,7 @@ public class MisoScene implements Scene
     }
 
     /**
-     * Return the portal with the given name, or null if the portal
-     * isn't found in the portal list.
-     *
-     * @param name the portal name.
-     *
-     * @return the portal object.
-     */
-    public Portal getPortal (String name)
-    {
-	int size = _portals.size();
-	for (int ii = 0; ii < size; ii++) {
-	    Portal portal = (Portal)_portals.get(ii);
-	    if (portal.name.equals(name)) return portal;
-	}
-	return null;
-    }
-
-    /**
-     * Return a string representation of this Scene object.
+     * Return a string representation of this Miso scene object.
      */
     public String toString ()
     {
@@ -341,6 +251,9 @@ public class MisoScene implements Scene
     /** The unique scene id. */
     protected int _sid;
 
+    /** The tiles comprising the scene. */
+    public Tile[][][] _tiles;
+
     /** The default entrance portal. */
     protected Portal _entrance;
 
diff --git a/src/java/com/threerings/miso/client/IsoSceneView.java b/src/java/com/threerings/miso/client/IsoSceneView.java
index 0788bb97b..ea39fa4ac 100644
--- a/src/java/com/threerings/miso/client/IsoSceneView.java
+++ b/src/java/com/threerings/miso/client/IsoSceneView.java
@@ -1,5 +1,5 @@
 //
-// $Id: IsoSceneView.java,v 1.54 2001/09/13 19:10:26 mdb Exp $
+// $Id: IsoSceneView.java,v 1.55 2001/09/21 02:30:35 mdb Exp $
 
 package com.threerings.miso.scene;
 
@@ -17,12 +17,13 @@ import com.threerings.media.tile.TileManager;
 import com.threerings.miso.Log;
 import com.threerings.miso.scene.util.AStarPathUtil;
 import com.threerings.miso.scene.util.IsoUtil;
+import com.threerings.miso.scene.util.MisoSceneUtil;
 
 /**
  * The <code>IsoSceneView</code> provides an isometric view of a
  * particular scene.
  */
-public class IsoSceneView implements EditableSceneView
+public class IsoSceneView implements SceneView
 {
     /**
      * Construct an <code>IsoSceneView</code> object.
@@ -39,10 +40,6 @@ public class IsoSceneView implements EditableSceneView
 
         setModel(model);
 
-        // initialize the highlighted objects
-	_htile = new Point(-1, -1);
-	_hfull = new Point(-1, -1);
-
         // get the font used to render tile coordinates
 	_font = new Font("Arial", Font.PLAIN, 7);
 
@@ -65,6 +62,12 @@ public class IsoSceneView implements EditableSceneView
 	clearDirtyRegions();
     }
 
+    // documentation inherited
+    public void setScene (MisoScene scene)
+    {
+        _scene = scene;
+    }
+
     /**
      * Paint the scene view and any highlighted tiles to the given
      * graphics context.
@@ -73,7 +76,9 @@ public class IsoSceneView implements EditableSceneView
      */
     public void paint (Graphics g)
     {
-	if (_scene == null) return;
+	if (_scene == null) {
+            return;
+        }
 
 	Graphics2D gfx = (Graphics2D)g;
 
@@ -107,13 +112,21 @@ public class IsoSceneView implements EditableSceneView
 	    paintLocations(gfx);
 	}
 
-        // draw highlighted tiles and full coordinates
-	paintHighlights(gfx);
+        // paint any extra goodies
+	paintExtras(gfx);
 
 	// restore the original clipping region
 	gfx.setClip(oldclip);
     }
 
+    /**
+     * A function where derived classes can paint extra stuff while we've
+     * got the clipping region set up.
+     */
+    protected void paintExtras (Graphics2D g)
+    {
+    }
+
     protected void clearDirtyRegions ()
     {
 	_dirtyRects.clear();
@@ -155,6 +168,7 @@ public class IsoSceneView implements EditableSceneView
     protected void renderSceneInvalid (Graphics2D gfx)
     {
 	int numDrawn = 0;
+        Tile[][][] tiles = _scene.getTiles();
 
 	for (int yy = 0; yy < _model.scenehei; yy++) {
 	    for (int xx = 0; xx < _model.scenewid; xx++) {
@@ -169,7 +183,7 @@ public class IsoSceneView implements EditableSceneView
 		for (int kk = 0; kk < MisoScene.NUM_LAYERS; kk++) {
 
 		    // get the tile at these coordinates and layer
-		    Tile tile = _scene.tiles[xx][yy][kk];
+		    Tile tile = tiles[xx][yy][kk];
 		    if (tile == null) continue;
 
 		    // offset the image y-position by the tile-specific height
@@ -202,6 +216,7 @@ public class IsoSceneView implements EditableSceneView
      */
     protected void renderScene (Graphics2D gfx)
     {
+        Tile[][][] tiles = _scene.getTiles();
 	int mx = 1;
 	int my = 0;
 
@@ -222,7 +237,7 @@ public class IsoSceneView implements EditableSceneView
 
 		for (int kk = 0; kk < MisoScene.NUM_LAYERS; kk++) {
 		    // grab the tile we're rendering
-		    Tile tile = _scene.tiles[tx][ty][kk];
+		    Tile tile = tiles[tx][ty][kk];
 		    if (tile == null) continue;
 
 		    // determine screen y-position, accounting for
@@ -290,45 +305,6 @@ public class IsoSceneView implements EditableSceneView
         gfx.drawString(str, sx + cx - (fm.stringWidth(str)/2), sy + cy + fhei);
     }
 
-    /**
-     * Paint highlights around any highlighted tiles and fine coordinates.
-     *
-     * @param gfx the graphics context.
-     */
-    protected void paintHighlights (Graphics2D gfx)
-    {
-	// paint the highlighted tile
-	if (_htile.x != -1 && _htile.y != -1) {
-	    // set the desired stroke and color
-	    Stroke ostroke = gfx.getStroke();
-	    gfx.setStroke(_hstroke);
-	    gfx.setColor(Color.green);
-
-	    // draw the tile outline
-	    gfx.draw(_polys[_htile.x][_htile.y]);
-
-	    // restore the original stroke
-	    gfx.setStroke(ostroke);
-	}
-
-	// paint the highlighted full coordinate
-	if (_hfull.x != -1 && _hfull.y != -1) {
-	    Point spos = new Point();
-	    IsoUtil.fullToScreen(_model, _hfull.x, _hfull.y, spos);
-
-	    // set the desired stroke and color
-	    Stroke ostroke = gfx.getStroke();
-	    gfx.setStroke(_hstroke);
-
-	    // draw a red circle at the coordinate
-	    gfx.setColor(Color.red);
-	    gfx.draw(new Ellipse2D.Float(spos.x - 1, spos.y - 1, 3, 3));
-
-	    // restore the original stroke
-	    gfx.setStroke(ostroke);
-	}
-    }
-
     /**
      * Paint demarcations at all locations in the scene, with each
      * location's cluster index, if any, along the right side of its
@@ -338,8 +314,8 @@ public class IsoSceneView implements EditableSceneView
      */
     protected void paintLocations (Graphics2D gfx)
     {
-	ArrayList locations = _scene.getLocations();
-	int size = locations.size();
+	Location[] locations = _scene.getLocations();
+	int size = locations.length;
 
 	// create the location triangle
 	Polygon tri = new Polygon();
@@ -350,10 +326,10 @@ public class IsoSceneView implements EditableSceneView
 	for (int ii = 0; ii < size; ii++) {
 
 	    // retrieve the location
-	    Location loc = (Location)locations.get(ii);
+	    Location loc = locations[ii];
 
 	    // get the cluster index this location is in, if any
-	    int clusteridx = _scene.getClusterIndex(loc);
+	    int clusteridx = MisoSceneUtil.getClusterIndex(_scene, loc);
 
 	    Point spos = new Point();
 	    IsoUtil.fullToScreen(_model, loc.x, loc.y, spos);
@@ -393,26 +369,6 @@ public class IsoSceneView implements EditableSceneView
 	}
     }
 
-    public void setHighlightedTile (int sx, int sy)
-    {
-	if (sx == -1 && sy == -1) {
-	    _htile.setLocation(-1, -1);
-	    return;
-	}
-
-        IsoUtil.screenToTile(_model, sx, sy, _htile);
-    }
-
-    public void setHighlightedFull (int x, int y)
-    {
-	if (x == -1 && y == -1) {
-	    _hfull.setLocation(-1, -1);
-	    return;
-	}
-
-	IsoUtil.screenToFull(_model, x, y, _hfull);
-    }
-
     /**
      * Invalidate a list of rectangles in the view for later repainting.
      *
@@ -560,27 +516,6 @@ public class IsoSceneView implements EditableSceneView
         _spritemgr.invalidateIntersectingSprites(rects, _polys[x][y]);
     }
 
-    public void setScene (MisoScene scene)
-    {
-	_scene = scene;
-    }
-
-    public void setTile (int x, int y, int lnum, Tile tile)
-    {
-	Point tpos = new Point();
-        IsoUtil.screenToTile(_model, x, y, tpos);
-	_scene.tiles[tpos.x][tpos.y][lnum] = tile;
-    }
-
-    public void deleteTile (int x, int y, int lnum)
-    {
-	Point tpos = new Point();
-        IsoUtil.screenToTile(_model, x, y, tpos);
-
-	Tile tile = (lnum == 0) ? _scene.getDefaultTile() : null;
-	_scene.tiles[tpos.x][tpos.y][lnum] = tile;
-    }
-
     public void setModel (IsoSceneViewModel model)
     {
         _model = model;
@@ -608,7 +543,7 @@ public class IsoSceneView implements EditableSceneView
 	// get a reasonable path from start to end
 	List tilepath =
 	    AStarPathUtil.getPath(
-		_scene.tiles, _model.scenewid, _model.scenehei,
+		_scene.getTiles(), _model.scenewid, _model.scenehei,
 		sprite, stpos.x, stpos.y, tbx, tby);
 	if (tilepath == null) {
 	    return null;
@@ -666,54 +601,6 @@ public class IsoSceneView implements EditableSceneView
         return path;
     }
 
-    public void updateLocation (Location loc, int clusteridx)
-    {
-	_scene.updateLocation(loc, clusteridx);
-    }
-
-    public void addPortal (Portal portal)
-    {
-	_scene.addPortal(portal);
-    }
-
-    public void removeLocation (Location loc)
-    {
-	_scene.removeLocation(loc);
-    }
-
-    public Location createLocation (int sx, int sy)
-    {
-	Point fpos = new Point();
-	IsoUtil.screenToFull(_model, sx, sy, fpos);
-	return new Location(fpos.x, fpos.y);
-    }
-
-    public Location getLocation (int sx, int sy)
-    {
-	Point fpos = new Point();
-	IsoUtil.screenToFull(_model, sx, sy, fpos);
-	return _scene.getLocation(fpos.x, fpos.y);
-    }
-
-    public int getClusterIndex (Location loc)
-    {
-	return _scene.getClusterIndex(loc);
-    }
-
-    public int getNumClusters ()
-    {
-	return (_scene == null) ? 0 : _scene.getNumClusters();
-    }
-
-    /** The stroke object used to draw highlighted tiles and coordinates. */
-    protected BasicStroke _hstroke = new BasicStroke(3);
-
-    /** The currently highlighted tile. */
-    protected Point _htile;
-
-    /** The currently highlighted full coordinate. */
-    protected Point _hfull;
-
     /** The font to draw tile coordinates. */
     protected Font _font;
 
diff --git a/src/java/com/threerings/miso/client/MisoScene.java b/src/java/com/threerings/miso/client/MisoScene.java
new file mode 100644
index 000000000..2a5efcc51
--- /dev/null
+++ b/src/java/com/threerings/miso/client/MisoScene.java
@@ -0,0 +1,57 @@
+//
+// $Id: MisoScene.java,v 1.1 2001/09/21 02:30:35 mdb Exp $
+
+package com.threerings.miso.scene;
+
+import com.threerings.media.tile.Tile;
+import com.threerings.whirled.data.Scene;
+
+/**
+ * A scene object represents the data model corresponding to a single
+ * screen for game play. For instance, one scene might display a portion
+ * of a street with several buildings scattered about on the periphery.
+ */
+public interface MisoScene extends Scene
+{
+    /** The total number of layers. */
+    public static final int NUM_LAYERS = 3;
+
+    /** The base layer id. */
+    public static final int LAYER_BASE = 0;
+
+    /** The fringe layer id. */
+    public static final int LAYER_FRINGE = 1;
+
+    /** The object layer id. */
+    public static final int LAYER_OBJECT = 2;
+
+    /**
+     * Return the tiles that comprise this scene.
+     */
+    public Tile[][][] getTiles ();
+
+    /**
+     * Return the default tile for the base layer of the scene.
+     */
+    public Tile getDefaultTile ();
+
+    /**
+     * Return the locations in this scene.
+     */
+    public Location[] getLocations ();
+
+    /**
+     * Return the clusters in this scene.
+     */
+    public Cluster[] getClusters ();
+
+    /**
+     * Return the portals associated with this scene.
+     */
+    public Portal[] getPortals ();
+
+    /**
+     * Return the portal that is the default entrance to this scene.
+     */
+    public Portal getEntrance ();
+}
diff --git a/src/java/com/threerings/miso/client/SceneViewPanel.java b/src/java/com/threerings/miso/client/SceneViewPanel.java
index 9ffc45b74..589d7e5c0 100644
--- a/src/java/com/threerings/miso/client/SceneViewPanel.java
+++ b/src/java/com/threerings/miso/client/SceneViewPanel.java
@@ -1,5 +1,5 @@
 //
-// $Id: SceneViewPanel.java,v 1.13 2001/08/29 18:41:46 shaper Exp $
+// $Id: SceneViewPanel.java,v 1.14 2001/09/21 02:30:35 mdb Exp $
 
 package com.threerings.miso.scene;
 
@@ -30,13 +30,22 @@ public class SceneViewPanel
         _smodel = new IsoSceneViewModel(config);
 
 	// create the scene view
-        _view = new IsoSceneView(tilemgr, spritemgr, _smodel);
+        _view = newSceneView(tilemgr, spritemgr, _smodel);
 
 	// set our attributes for optimal display performance
         setDoubleBuffered(false);
         setOpaque(true);
     }
 
+    /**
+     * Constructs the underlying scene view implementation.
+     */
+    protected IsoSceneView newSceneView (
+        TileManager tmgr, SpriteManager smgr, IsoSceneViewModel model)
+    {
+        return new IsoSceneView(tmgr, smgr, model);
+    }
+
     /**
      * Set the scene managed by the panel.
      */
diff --git a/src/java/com/threerings/miso/client/util/ClusterUtil.java b/src/java/com/threerings/miso/client/util/ClusterUtil.java
index 3be0fbf93..cdda5b35d 100644
--- a/src/java/com/threerings/miso/client/util/ClusterUtil.java
+++ b/src/java/com/threerings/miso/client/util/ClusterUtil.java
@@ -1,5 +1,5 @@
 //
-// $Id: ClusterUtil.java,v 1.1 2001/08/14 21:29:40 shaper Exp $
+// $Id: ClusterUtil.java,v 1.2 2001/09/21 02:30:35 mdb Exp $
 
 package com.threerings.miso.scene.util;
 
@@ -22,12 +22,14 @@ public class ClusterUtil
      * @param clusters the cluster list.
      * @param loc the location.
      */
-    public static int getClusterIndex (ArrayList clusters, Location loc)
+    public static int getClusterIndex (Cluster[] clusters, Location loc)
     {
-	int size = clusters.size();
+	int size = clusters.length;
 	for (int ii = 0; ii < size; ii++) {
-	    Cluster cluster = (Cluster)clusters.get(ii);
-	    if (cluster.contains(loc)) return ii;
+	    Cluster cluster = clusters[ii];
+	    if (cluster.contains(loc)) {
+                return ii;
+            }
 	}
 	return -1;
     }
@@ -35,7 +37,7 @@ public class ClusterUtil
     /**
      * Remove the given location from its cluster, if any.
      *
-     * @param clusters the cluster list.
+     * @param clusters the cluster array.
      * @param loc the location.
      */
     public static void remove (ArrayList clusters, Location loc)
diff --git a/src/java/com/threerings/miso/client/util/MisoSceneUtil.java b/src/java/com/threerings/miso/client/util/MisoSceneUtil.java
new file mode 100644
index 000000000..76d6d30d2
--- /dev/null
+++ b/src/java/com/threerings/miso/client/util/MisoSceneUtil.java
@@ -0,0 +1,75 @@
+//
+// $Id: MisoSceneUtil.java,v 1.1 2001/09/21 02:30:35 mdb Exp $
+
+package com.threerings.miso.scene.util;
+
+import com.threerings.miso.scene.*;
+
+/**
+ * Miso scene related utility functions and information.
+ */
+public class MisoSceneUtil
+{
+    /** String translations of each tile layer name. */
+    public static final String[] XLATE_LAYERS = { "Base", "Fringe", "Object" };
+
+    /**
+     * Return the location object at the given full coordinates, or null
+     * if no location is currently present at that location.
+     *
+     * @param scene the scene whose locations should be searched.
+     * @param x the full x-position coordinate.
+     * @param y the full y-position coordinate.
+     *
+     * @return the location object.
+     */
+    public static Location getLocation (MisoScene scene, int x, int y)
+    {
+        Location[] locs = scene.getLocations();
+	int size = locs.length;
+	for (int ii = 0; ii < size; ii++) {
+	    Location loc = locs[ii];
+	    if (loc.x == x && loc.y == y) {
+                return loc;
+            }
+	}
+	return null;
+    }
+
+    /**
+     * Return the portal with the given name, or null if the portal isn't
+     * found in the portal list.
+     *
+     * @param scene the scene whose portals should be searched.
+     * @param name the portal name.
+     *
+     * @return the portal object.
+     */
+    public static Portal getPortal (MisoScene scene, String name)
+    {
+        Portal[] portals = scene.getPortals();
+	int size = portals.length;
+	for (int ii = 0; ii < size; ii++) {
+	    Portal portal = portals[ii];
+	    if (portal.name.equals(name)) {
+                return portal;
+            }
+	}
+	return null;
+    }
+
+    /**
+     * Return the cluster index number the given location is in, or -1
+     * if the location is not in any cluster.
+     *
+     * @param scene the containing scene.
+     * @param loc the location.
+     *
+     * @return the cluster index or -1 if the location is not in any
+     * cluster.
+     */
+    public static int getClusterIndex (MisoScene scene, Location loc)
+    {
+	return ClusterUtil.getClusterIndex(scene.getClusters(), loc);
+    }
+}
diff --git a/src/java/com/threerings/miso/tools/EditableMisoScene.java b/src/java/com/threerings/miso/tools/EditableMisoScene.java
new file mode 100644
index 000000000..41f821919
--- /dev/null
+++ b/src/java/com/threerings/miso/tools/EditableMisoScene.java
@@ -0,0 +1,52 @@
+//
+// $Id: EditableMisoScene.java,v 1.1 2001/09/21 02:30:35 mdb Exp $
+
+package com.threerings.miso.scene;
+
+import com.threerings.whirled.data.EditableScene;
+
+/**
+ * The editable Miso scene interface provides the means for modifying a
+ * Miso scene which is needed by things like the scene editor. This is
+ * separated from the read-only interface to avoid implying to users of
+ * the Miso scene interface that editing scenes is a safe thing to do. In
+ * fact it should only be done under special circumstances.
+ */
+public interface EditableMisoScene
+    extends EditableScene, MisoScene
+{
+    /**
+     * Set the default entrance portal for this scene.
+     *
+     * @param entrance the entrance portal.
+     */
+    public void setEntrance (Portal entrance);
+
+    /**
+     * Update the specified location in the scene.  If the cluster
+     * index number is -1, the location will be removed from any
+     * cluster it may reside in.
+     *
+     * @param loc the location.
+     * @param clusteridx the cluster index number.
+     */
+    public void updateLocation (Location loc, int clusteridx);
+
+    /**
+     * Add the specified portal to the scene.  Adds the portal to the
+     * location list as well if it's not already present and removes
+     * it from any cluster it may reside in.
+     *
+     * @param portal the portal.
+     */
+    public void addPortal (Portal portal);
+
+    /**
+     * Remove the given location object from the location list, and
+     * from any containing cluster.  If the location is a portal, it
+     * is removed from the portal list as well.
+     *
+     * @param loc the location object.
+     */
+    public void removeLocation (Location loc);
+}
diff --git a/src/java/com/threerings/miso/tools/xml/XMLSceneGroupParser.java b/src/java/com/threerings/miso/tools/xml/XMLSceneGroupParser.java
index 8037ff834..b6cfa5610 100644
--- a/src/java/com/threerings/miso/tools/xml/XMLSceneGroupParser.java
+++ b/src/java/com/threerings/miso/tools/xml/XMLSceneGroupParser.java
@@ -1,5 +1,5 @@
 //
-// $Id: XMLSceneGroupParser.java,v 1.3 2001/08/21 01:15:16 shaper Exp $
+// $Id: XMLSceneGroupParser.java,v 1.4 2001/09/21 02:30:35 mdb Exp $
 
 package com.threerings.miso.scene.xml;
 
@@ -14,6 +14,7 @@ import com.samskivert.util.*;
 import com.samskivert.xml.XMLUtil;
 import com.threerings.miso.Log;
 import com.threerings.miso.scene.*;
+import com.threerings.miso.scene.util.MisoSceneUtil;
 import com.threerings.whirled.data.Scene;
 
 /**
@@ -228,7 +229,7 @@ public class XMLSceneGroupParser extends DefaultHandler
 	protected void resolvePortal (SceneInfo sinfo, PortalInfo pinfo)
 	{
 	    // get the source portal object
-	    Portal src = sinfo.scene.getPortal(pinfo.src);
+	    Portal src = MisoSceneUtil.getPortal(sinfo.scene, pinfo.src);
 	    if (src == null) {
 		Log.warning("Missing source portal [scene=" + sinfo.name +
 			    ", pinfo=" + pinfo + "].");
@@ -244,7 +245,7 @@ public class XMLSceneGroupParser extends DefaultHandler
 	    }
 
 	    // get the destination portal object
-	    Portal dest = destScene.getPortal(pinfo.dest);
+	    Portal dest = MisoSceneUtil.getPortal(destScene, pinfo.dest);
 	    if (dest == null) {
 		Log.warning("Missing destination portal [scene=" + sinfo.name +
 			    ", pinfo=" + pinfo + "].");
@@ -262,7 +263,8 @@ public class XMLSceneGroupParser extends DefaultHandler
 	 */
 	protected void resolveEntrance (SceneInfo sinfo)
 	{
-	    Portal entrance = sinfo.scene.getPortal(sinfo.entrance);
+	    Portal entrance = MisoSceneUtil.getPortal(
+                sinfo.scene, sinfo.entrance);
 	    if (entrance == null) {
 		Log.warning( "Missing entrance portal [scene=" + sinfo.name +
 			     ", entrance=" + sinfo.entrance + "].");
@@ -289,12 +291,12 @@ public class XMLSceneGroupParser extends DefaultHandler
 		SceneInfo sinfo = (SceneInfo)sceneinfo.get(ii);
 
 		// get the portals in the scene
-		List portals = sinfo.scene.getPortals();
+		Portal[] portals = sinfo.scene.getPortals();
 
 		// check each portal to make sure it has a valid destination
-		int psize = portals.size();
+		int psize = portals.length;
 		for (int jj = 0; jj < size; jj++) {
-		    Portal portal = (Portal)portals.get(jj);
+		    Portal portal = portals[jj];
 		    if (!portal.hasDestination()) {
 			Log.warning("Unbound portal [scene=" + sinfo.name +
 				    ", portal=" + portal + "].");
@@ -322,7 +324,7 @@ public class XMLSceneGroupParser extends DefaultHandler
 	public ArrayList portals;
 
 	/** The scene object obtained from the scene repository. */
-	public MisoScene scene;
+	public MisoSceneImpl scene;
 
 	public SceneInfo (String src)
 	{
diff --git a/src/java/com/threerings/miso/tools/xml/XMLSceneParser.java b/src/java/com/threerings/miso/tools/xml/XMLSceneParser.java
index 0c0b1ddbb..56f055881 100644
--- a/src/java/com/threerings/miso/tools/xml/XMLSceneParser.java
+++ b/src/java/com/threerings/miso/tools/xml/XMLSceneParser.java
@@ -1,5 +1,5 @@
 //
-// $Id: XMLSceneParser.java,v 1.15 2001/08/29 19:50:46 shaper Exp $
+// $Id: XMLSceneParser.java,v 1.16 2001/09/21 02:30:35 mdb Exp $
 
 package com.threerings.miso.scene.xml;
 
@@ -60,12 +60,12 @@ public class XMLSceneParser extends DefaultHandler
 
 	} else if (qName.equals("version")) {
             int version = getInt(_chars.toString());
-            if (version < 0 || version > MisoScene.VERSION) {
+            if (version < 0 || version > XMLSceneVersion.VERSION) {
                 Log.warning(
                     "Unrecognized scene file format version, will attempt " + 
                     "to continue parsing file but your mileage may vary " +
                     "[fname=" + _fname + ", version=" + version +
-                    ", known_version=" + MisoScene.VERSION + "].");
+                    ", known_version=" + XMLSceneVersion.VERSION + "].");
             }
 
 	} else if (qName.equals("locations")) {
@@ -280,7 +280,7 @@ public class XMLSceneParser extends DefaultHandler
      *
      * @return the scene object, or null if an error occurred.
      */
-    public MisoScene loadScene (String fname) throws IOException
+    public EditableMisoScene loadScene (String fname) throws IOException
     {
         _fname = fname;
 
@@ -354,7 +354,7 @@ public class XMLSceneParser extends DefaultHandler
 	public int colstart;
 
 	/** The scene object constructed once all scene info is parsed. */
-	public MisoScene scene;
+	public EditableMisoScene scene;
 
 	public SceneInfo ()
 	{
@@ -365,7 +365,7 @@ public class XMLSceneParser extends DefaultHandler
 
 	public void constructScene (TileManager tilemgr)
 	{
-	    scene = new MisoScene(
+	    scene = new MisoSceneImpl(
                 _model, tilemgr, name, locations, clusters, portals, tiles);
 	}
     }
diff --git a/src/java/com/threerings/miso/tools/xml/XMLSceneRepository.java b/src/java/com/threerings/miso/tools/xml/XMLSceneRepository.java
index 8ed133d76..a1d3bb114 100644
--- a/src/java/com/threerings/miso/tools/xml/XMLSceneRepository.java
+++ b/src/java/com/threerings/miso/tools/xml/XMLSceneRepository.java
@@ -1,5 +1,5 @@
 //
-// $Id: XMLSceneRepository.java,v 1.11 2001/08/29 19:50:46 shaper Exp $
+// $Id: XMLSceneRepository.java,v 1.12 2001/09/21 02:30:35 mdb Exp $
 
 package com.threerings.miso.scene.xml;
 
@@ -12,6 +12,7 @@ import com.threerings.media.tile.TileManager;
 import com.threerings.miso.Log;
 import com.threerings.miso.scene.IsoSceneViewModel;
 import com.threerings.miso.scene.MisoScene;
+import com.threerings.miso.scene.EditableMisoScene;
 import com.threerings.miso.util.MisoUtil;
 
 /**
@@ -63,7 +64,7 @@ public class XMLFileSceneRepository
      * @param fname the full pathname to the file.
      * @return the scene object.
      */
-    public MisoScene loadScene (String fname) throws IOException
+    public EditableMisoScene loadScene (String fname) throws IOException
     {
 	String path = getScenePath() + fname;
 	Log.info("Loading scene [path=" + path + "].");
diff --git a/src/java/com/threerings/miso/tools/xml/XMLSceneVersion.java b/src/java/com/threerings/miso/tools/xml/XMLSceneVersion.java
new file mode 100644
index 000000000..96910e42c
--- /dev/null
+++ b/src/java/com/threerings/miso/tools/xml/XMLSceneVersion.java
@@ -0,0 +1,15 @@
+//
+// $Id: XMLSceneVersion.java,v 1.1 2001/09/21 02:30:35 mdb Exp $
+
+package com.threerings.miso.scene.xml;
+
+/**
+ * This class tracks the version number of the XML scene file format. When
+ * modifications are made to the file format, the version number in this
+ * class should be increased.
+ */
+public class XMLSceneVersion
+{
+    /** The latest scene file format version. */
+    public static int VERSION = 1;
+}
diff --git a/src/java/com/threerings/miso/tools/xml/XMLSceneWriter.java b/src/java/com/threerings/miso/tools/xml/XMLSceneWriter.java
index f2926fab7..90f6135b2 100644
--- a/src/java/com/threerings/miso/tools/xml/XMLSceneWriter.java
+++ b/src/java/com/threerings/miso/tools/xml/XMLSceneWriter.java
@@ -1,5 +1,5 @@
 //
-// $Id: XMLSceneWriter.java,v 1.12 2001/08/29 19:50:46 shaper Exp $
+// $Id: XMLSceneWriter.java,v 1.13 2001/09/21 02:30:35 mdb Exp $
 
 package com.threerings.miso.scene.xml;
 
@@ -7,9 +7,10 @@ import java.awt.Point;
 import java.io.*;
 import java.util.ArrayList;
 
+import com.samskivert.util.ListUtil;
+
 import org.xml.sax.*;
 import org.xml.sax.helpers.AttributesImpl;
-
 import com.megginson.sax.DataWriter;
 
 import com.threerings.media.tile.Tile;
@@ -52,7 +53,7 @@ public class XMLSceneWriter extends DataWriter
             startElement("scene");
 
             dataElement("name", scene.getName());
-            dataElement("version", "" + MisoScene.VERSION);
+            dataElement("version", "" + XMLSceneVersion.VERSION);
             dataElement("locations", getLocationData(scene));
 
 	    startElement("clusters");
@@ -86,21 +87,22 @@ public class XMLSceneWriter extends DataWriter
      */
     protected void writeClusters (MisoScene scene) throws SAXException
     {
-	ArrayList clusters = scene.getClusters();
-	ArrayList locs = scene.getLocations();
+	Cluster[] clusters = scene.getClusters();
+	Location[] locs = scene.getLocations();
 
-	int size = clusters.size();
+	int size = clusters.length;
 	for (int ii = 0; ii < size; ii++) {
-
-	    StringBuffer buf = new StringBuffer();
-
-	    Cluster cluster = (Cluster)clusters.get(ii);
+	    Cluster cluster = clusters[ii];
 	    ArrayList clusterlocs = cluster.getLocations();
 
+	    StringBuffer buf = new StringBuffer();
 	    int clustersize = clusterlocs.size();
 	    for (int jj = 0; jj < clustersize; jj++) {
-		buf.append(locs.indexOf(clusterlocs.get(jj)));
-		if (jj < clustersize - 1) buf.append(",");
+                Location cloc = (Location)clusterlocs.get(jj);
+		buf.append(ListUtil.indexOfEqual(locs, cloc));
+		if (jj < clustersize - 1) {
+                    buf.append(",");
+                }
 	    }
 
 	    dataElement("cluster", buf.toString());
@@ -144,16 +146,18 @@ public class XMLSceneWriter extends DataWriter
      */
     protected String getPortalData (MisoScene scene)
     {
-	ArrayList locs = scene.getLocations();
-	ArrayList portals = scene.getPortals();
+	Location[] locs = scene.getLocations();
+	Portal[] portals = scene.getPortals();
 
         StringBuffer buf = new StringBuffer();
-	int size = portals.size();
+	int size = portals.length;
         for (int ii = 0; ii < size; ii++) {
-	    Portal portal = (Portal)portals.get(ii);
-	    buf.append(locs.indexOf(portal)).append(",");
+	    Portal portal = portals[ii];
+	    buf.append(ListUtil.indexOfEqual(locs, portal)).append(",");
 	    buf.append(portal.name);
-            if (ii < size - 1) buf.append(",");
+            if (ii < size - 1) {
+                buf.append(",");
+            }
         }
 
         return buf.toString();
@@ -168,16 +172,18 @@ public class XMLSceneWriter extends DataWriter
      */
     protected String getLocationData (MisoScene scene)
     {
-	ArrayList locs = scene.getLocations();
+	Location[] locs = scene.getLocations();
 
         StringBuffer buf = new StringBuffer();
-	int size = locs.size();
+	int size = locs.length;
         for (int ii = 0; ii < size; ii++) {
-	    Location loc = (Location)locs.get(ii);
+	    Location loc = locs[ii];
 	    buf.append(loc.x).append(",");
 	    buf.append(loc.y).append(",");
 	    buf.append(loc.orient);
-            if (ii < size - 1) buf.append(",");
+            if (ii < size - 1) {
+                buf.append(",");
+            }
         }
 
         return buf.toString();
@@ -201,10 +207,11 @@ public class XMLSceneWriter extends DataWriter
                                   int colstart, int len)
     {
         StringBuffer buf = new StringBuffer();
+        Tile[][][] tiles = scene.getTiles();
 
         int numtiles = colstart + len;
         for (int ii = colstart; ii < numtiles; ii++) {
-            Tile tile = scene.tiles[ii][rownum][lnum];
+            Tile tile = tiles[ii][rownum][lnum];
             if (tile == null) {
                 Log.warning("Null tile [x=" + ii + ", rownum=" + rownum +
                             ", lnum=" + lnum + "].");
@@ -213,7 +220,9 @@ public class XMLSceneWriter extends DataWriter
 
             buf.append(tile.tsid).append(",");
             buf.append(tile.tid);
-            if (ii != numtiles - 1) buf.append(",");
+            if (ii != numtiles - 1) {
+                buf.append(",");
+            }
         }
 
         return buf.toString();
@@ -265,15 +274,21 @@ public class XMLSceneWriter extends DataWriter
     protected boolean getSparseColumn (
         MisoScene scene, int rownum, int lnum, int info[])
     {
+        Tile[][][] tiles = scene.getTiles();
         int start = -1, len = 0;
         for (int xx = info[0]; xx < _model.scenewid; xx++) {
-            Tile tile = scene.tiles[xx][rownum][lnum];
+            Tile tile = tiles[xx][rownum][lnum];
             if (tile == null) {
-                if (start == -1) continue;
-                else break;
+                if (start == -1) {
+                    continue;
+                } else {
+                    break;
+                }
             }
 
-            if (start == -1) start = xx;
+            if (start == -1) {
+                start = xx;
+            }
             len++;
         }
 
diff --git a/src/java/com/threerings/whirled/data/EditableScene.java b/src/java/com/threerings/whirled/data/EditableScene.java
new file mode 100644
index 000000000..fad541c56
--- /dev/null
+++ b/src/java/com/threerings/whirled/data/EditableScene.java
@@ -0,0 +1,17 @@
+//
+// $Id: EditableScene.java,v 1.1 2001/09/21 02:30:35 mdb Exp $
+
+package com.threerings.whirled.data;
+
+/**
+ * The editable scene interface. This separate interface allows the
+ * ability to modify the scenes to be restricted only to code that needs
+ * such an ability.
+ */
+public interface EditableScene extends Scene
+{
+    /**
+     * Updates the scene's name.
+     */
+    public void setName (String name);
+}
diff --git a/src/java/com/threerings/whirled/data/Scene.java b/src/java/com/threerings/whirled/data/Scene.java
index 4ecb2b81f..cc05de346 100644
--- a/src/java/com/threerings/whirled/data/Scene.java
+++ b/src/java/com/threerings/whirled/data/Scene.java
@@ -1,5 +1,5 @@
 //
-// $Id: Scene.java,v 1.3 2001/09/21 00:21:40 mdb Exp $
+// $Id: Scene.java,v 1.4 2001/09/21 02:30:35 mdb Exp $
 
 package com.threerings.whirled.data;
 
@@ -9,6 +9,9 @@ package com.threerings.whirled.data;
  */
 public interface Scene
 {
+    /** Scene id to denote an unset or otherwise invalid scene id. */
+    public static final int SID_INVALID = -1;
+
     /**
      * Returns the scene's unique identifier.
      */