diff --git a/data/water.png b/data/water.png
index 785a95856..20f74edfe 100644
Binary files a/data/water.png and b/data/water.png differ
diff --git a/genmap.py b/genmap.py
index 8949888a4..8f7d421b1 100755
--- a/genmap.py
+++ b/genmap.py
@@ -1,5 +1,9 @@
 #!/usr/bin/python
 
+"
+This is an example script that generates some valid map data.
+"
+
 import struct
 import random
 
diff --git a/src/client.cpp b/src/client.cpp
index cede0af86..513be6d4b 100644
--- a/src/client.cpp
+++ b/src/client.cpp
@@ -1040,97 +1040,103 @@ void Client::ProcessData(u8 *data, u32 datasize, u16 sender_peer_id)
 	}
 	else if(command == TOCLIENT_ACTIVE_OBJECT_REMOVE_ADD)
 	{
-		/*
-			u16 command
-			u16 count of removed objects
-			for all removed objects {
-				u16 id
-			}
-			u16 count of added objects
-			for all added objects {
-				u16 id
-				u8 type
-				u16 initialization data length
-				string initialization data
-			}
-		*/
-
-		char buf[6];
-		// Get all data except the command number
-		std::string datastring((char*)&data[2], datasize-2);
-		// Throw them in an istringstream
-		std::istringstream is(datastring, std::ios_base::binary);
-
-		// Read stuff
-		
-		// Read removed objects
-		is.read(buf, 2);
-		u16 removed_count = readU16((u8*)buf);
-		for(u16 i=0; i<removed_count; i++)
+		if(g_settings.getBool("enable_experimental"))
 		{
+			/*
+				u16 command
+				u16 count of removed objects
+				for all removed objects {
+					u16 id
+				}
+				u16 count of added objects
+				for all added objects {
+					u16 id
+					u8 type
+					u16 initialization data length
+					string initialization data
+				}
+			*/
+
+			char buf[6];
+			// Get all data except the command number
+			std::string datastring((char*)&data[2], datasize-2);
+			// Throw them in an istringstream
+			std::istringstream is(datastring, std::ios_base::binary);
+
+			// Read stuff
+			
+			// Read removed objects
 			is.read(buf, 2);
-			u16 id = readU16((u8*)buf);
-			// Remove it
+			u16 removed_count = readU16((u8*)buf);
+			for(u16 i=0; i<removed_count; i++)
 			{
-				JMutexAutoLock envlock(m_env_mutex);
-				m_env.removeActiveObject(id);
+				is.read(buf, 2);
+				u16 id = readU16((u8*)buf);
+				// Remove it
+				{
+					JMutexAutoLock envlock(m_env_mutex);
+					m_env.removeActiveObject(id);
+				}
 			}
-		}
-		
-		// Read added objects
-		is.read(buf, 2);
-		u16 added_count = readU16((u8*)buf);
-		for(u16 i=0; i<added_count; i++)
-		{
+			
+			// Read added objects
 			is.read(buf, 2);
-			u16 id = readU16((u8*)buf);
-			is.read(buf, 1);
-			u8 type = readU8((u8*)buf);
-			std::string data = deSerializeLongString(is);
-			// Add it
+			u16 added_count = readU16((u8*)buf);
+			for(u16 i=0; i<added_count; i++)
 			{
-				JMutexAutoLock envlock(m_env_mutex);
-				m_env.addActiveObject(id, type, data);
+				is.read(buf, 2);
+				u16 id = readU16((u8*)buf);
+				is.read(buf, 1);
+				u8 type = readU8((u8*)buf);
+				std::string data = deSerializeLongString(is);
+				// Add it
+				{
+					JMutexAutoLock envlock(m_env_mutex);
+					m_env.addActiveObject(id, type, data);
+				}
 			}
 		}
 	}
 	else if(command == TOCLIENT_ACTIVE_OBJECT_MESSAGES)
 	{
-		/*
-			u16 command
-			for all objects
-			{
-				u16 id
-				u16 message length
-				string message
-			}
-		*/
-		char buf[6];
-		// Get all data except the command number
-		std::string datastring((char*)&data[2], datasize-2);
-		// Throw them in an istringstream
-		std::istringstream is(datastring, std::ios_base::binary);
-		
-		while(is.eof() == false)
+		if(g_settings.getBool("enable_experimental"))
 		{
-			// Read stuff
-			is.read(buf, 2);
-			u16 id = readU16((u8*)buf);
-			if(is.eof())
-				break;
-			is.read(buf, 2);
-			u16 message_size = readU16((u8*)buf);
-			std::string message;
-			message.reserve(message_size);
-			for(u16 i=0; i<message_size; i++)
+			/*
+				u16 command
+				for all objects
+				{
+					u16 id
+					u16 message length
+					string message
+				}
+			*/
+			char buf[6];
+			// Get all data except the command number
+			std::string datastring((char*)&data[2], datasize-2);
+			// Throw them in an istringstream
+			std::istringstream is(datastring, std::ios_base::binary);
+			
+			while(is.eof() == false)
 			{
-				is.read(buf, 1);
-				message.append(buf, 1);
-			}
-			// Pass on to the environment
-			{
-				JMutexAutoLock envlock(m_env_mutex);
-				m_env.processActiveObjectMessage(id, message);
+				// Read stuff
+				is.read(buf, 2);
+				u16 id = readU16((u8*)buf);
+				if(is.eof())
+					break;
+				is.read(buf, 2);
+				u16 message_size = readU16((u8*)buf);
+				std::string message;
+				message.reserve(message_size);
+				for(u16 i=0; i<message_size; i++)
+				{
+					is.read(buf, 1);
+					message.append(buf, 1);
+				}
+				// Pass on to the environment
+				{
+					JMutexAutoLock envlock(m_env_mutex);
+					m_env.processActiveObjectMessage(id, message);
+				}
 			}
 		}
 	}
diff --git a/src/main.cpp b/src/main.cpp
index 721b2028c..ec4060868 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -160,6 +160,9 @@ TODO: Flowing water animation
 
 * Combine meshes to bigger ones in ClientMap and set them EHM_STATIC
 
+SUGG: Draw cubes in inventory directly with 3D drawing commands, so that
+      animating them is easier.
+
 Configuration:
 --------------
 
@@ -242,9 +245,6 @@ TODO: Mineral and ground material properties
 
 TODO: Flowing water to actually contain flow direction information
 
-TODO: Remove duplicate lighting implementation from Map (leave
-      VoxelManipulator, which is faster)
-
 FEATURE: Create a system that allows a huge amount of different "map
 	     generator modules/filters"
 
@@ -273,18 +273,27 @@ Mapgen v2:
   the other chunk making nasty straight walls when the other chunk
   is generated. Fix it.
 
+Mapgen v4 (not doing):
+* only_from_disk might not work anymore - check and fix it.
+* Make the generator to run in background and not blocking block
+  placement and transfer
+* Make chunks to be tiled vertically too
+* MAKE IT FASTER
+
 Mapgen v3:
 * Generate trees better
   - Add a "trees_added" flag to sector, or something
 * How 'bout making turbulence controlled so that for a given 2d position
   it can be completely turned off, and is usually so. This way generation
   can be sped up a lot.
+* Add a way to generate a block partly, so that trees are not added, like
+  the chunks in v2
+* Add mud "discretely", not by guessing from the noise
 
 Mapgen v4:
-* only_from_disk might not work anymore - check and fix it.
-* Make the generator to run in background and not blocking block
-  placement and transfer
-* Make chunks to be tiled vertically too
+* This will be the final way.
+* Generate blocks in the same way as chunks, by copying a voxelmanipulator
+  from the map that is one block larger in all directions.
 
 Misc. stuff:
 ------------
diff --git a/src/map.cpp b/src/map.cpp
index 6e1a62ca3..aabe84067 100644
--- a/src/map.cpp
+++ b/src/map.cpp
@@ -183,6 +183,9 @@ bool Map::isNodeUnderground(v3s16 p)
 	light_sources to re-light the area without the removed light.
 
 	values of from_nodes are lighting values.
+
+	There is a duplicate implementation of this in VoxelManipulator,
+	which is faster for large volumes
 */
 void Map::unspreadLight(enum LightBank bank,
 		core::map<v3s16, u8> & from_nodes,
@@ -366,6 +369,9 @@ void Map::unLightNeighbors(enum LightBank bank,
 /*
 	Lights neighbors of from_nodes, collects all them and then
 	goes on recursively.
+
+	There is a duplicate implementation of this in VoxelManipulator,
+	which is faster for large volumes
 */
 void Map::spreadLight(enum LightBank bank,
 		core::map<v3s16, bool> & from_nodes,
@@ -840,6 +846,8 @@ void Map::updateLighting(core::map<v3s16, MapBlock*> & a_blocks,
 	This is called after changing a node from transparent to opaque.
 	The lighting value of the node should be left as-is after changing
 	other values. This sets the lighting value to 0.
+
+	NOTE: This takes almost no time, the slow one is updateMeshes.
 */
 void Map::addNodeAndUpdate(v3s16 p, MapNode n,
 		core::map<v3s16, MapBlock*> &modified_blocks)
@@ -1036,6 +1044,7 @@ void Map::addNodeAndUpdate(v3s16 p, MapNode n,
 }
 
 /*
+	NOTE: This takes almost no time, the slow one is updateMeshes.
 */
 void Map::removeNodeAndUpdate(v3s16 p,
 		core::map<v3s16, MapBlock*> &modified_blocks)
@@ -1982,7 +1991,7 @@ bool get_have_sand_ground(u64 seed, v2f p)
 	double sandnoise = noise2d_perlin(
 			0.5+(float)p.X/500, 0.5+(float)p.Y/500,
 			seed+54290232, 6, 0.65);
-	return (sandnoise > 0.8);
+	return (sandnoise > 1.0);
 }
 
 // -1->0, 0->1, 1->0
@@ -4079,7 +4088,6 @@ MapChunk* ServerMap::generateChunkRaw(v2s16 chunkpos,
 {
 	DSTACK(__FUNCTION_NAME);
 
-
 	/*
 		Don't generate if already fully generated
 	*/
@@ -4095,6 +4103,7 @@ MapChunk* ServerMap::generateChunkRaw(v2s16 chunkpos,
 		}
 	}
 
+#if 0
 	dstream<<"generateChunkRaw(): Generating chunk "
 			<<"("<<chunkpos.X<<","<<chunkpos.Y<<")"
 			<<std::endl;
@@ -4733,7 +4742,7 @@ MapChunk* ServerMap::generateChunkRaw(v2s16 chunkpos,
 			block->updateDayNightDiff();
 		}
 	}
-
+#endif
 	
 	/*
 		Create chunk metadata
@@ -4947,7 +4956,8 @@ MapSector * ServerMap::emergeSector(v2s16 p2d,
 
 /*
 	NOTE: This is not used for main map generation, only for blocks
-	that are very high or low
+	that are very high or low.
+	NOTE: Now it is used mainly. Might change in the future.
 */
 MapBlock * ServerMap::generateBlock(
 		v3s16 p,
@@ -5130,18 +5140,15 @@ MapBlock * ServerMap::generateBlock(
 			float surface_y_f = 0;
 			s16 surface_y = 0;
 			
-			if(turbulence_is_used == false)
-			{
-				surface_y_f = base_rock_level_2d(m_seed, real_p2d_f),
-				surface_y = surface_y_f;
+			float noturb_surface_y_f = base_rock_level_2d(m_seed, real_p2d_f);
+			s16 noturb_surface_y = noturb_surface_y_f;
 				
-				// Get some statistics of surface height
-				if(surface_y < lowest_ground_y)
-					lowest_ground_y = surface_y;
-				if(surface_y > highest_ground_y)
-					highest_ground_y = surface_y;
-			}
-			
+			// Get some statistics of surface height
+			if(noturb_surface_y < lowest_ground_y)
+				lowest_ground_y = noturb_surface_y;
+			if(noturb_surface_y > highest_ground_y)
+				highest_ground_y = noturb_surface_y;
+
 			for(s16 y0=0; y0<MAP_BLOCKSIZE; y0++)
 			{
 	#if 1
@@ -5164,35 +5171,48 @@ MapBlock * ServerMap::generateBlock(
 				bool is_ground = false;
 				v3f real_pos_f = intToFloat(real_pos, 1);
 				
-				if(turbulence_is_used)
+				bool turb_for_node = (turbulence_is_used
+						&& real_y >= TURBULENCE_BOTTOM_CUTOFF_Y);
+
+				bool is_cavern = false;
+				
+				if(is_carved(m_seed, real_pos_f))
 				{
-					double depth_guess;
-					is_ground = is_base_ground(m_seed,
-							real_pos_f, &depth_guess);
-					
-					// Estimate the surface height
-					surface_y_f = (float)real_y + depth_guess;
-					surface_y = real_y + depth_guess;
-					
-					// Get some statistics of surface height
-					if(surface_y < lowest_ground_y)
-						lowest_ground_y = surface_y;
-					if(surface_y > highest_ground_y)
-						highest_ground_y = surface_y;
+					is_ground = false;
+					if(real_y < noturb_surface_y)
+						is_cavern = true;
 				}
 				else
 				{
-					if(is_carved(m_seed, real_pos_f))
-						is_ground = false;
+					if(turb_for_node)
+					{
+						double depth_guess;
+						is_ground = is_base_ground(m_seed,
+								real_pos_f, &depth_guess);
+						
+						// Estimate the surface height
+						surface_y_f = (float)real_y + depth_guess;
+						surface_y = real_y + depth_guess;
+						
+						// Get some statistics of surface height
+						if(surface_y < lowest_ground_y)
+							lowest_ground_y = surface_y;
+						if(surface_y > highest_ground_y)
+							highest_ground_y = surface_y;
+					}
 					else
-						is_ground = (real_y <= surface_y);
+					{
+						surface_y = noturb_surface_y;
+					}
+					
+					is_ground = (real_y <= surface_y);
 				}
 
 				// If node is not ground, it's air or water
 				if(is_ground == false)
 				{
 					// If under water level, it's water
-					if(real_y < WATER_LEVEL)
+					if(real_y < WATER_LEVEL && !is_cavern)
 					{
 						n.d = water_material;
 						u8 dist = 16;
@@ -7181,8 +7201,6 @@ void ClientMap::expireMeshes(bool only_daynight_diffed)
 
 void ClientMap::updateMeshes(v3s16 blockpos, u32 daynight_ratio)
 {
-	assert(mapType() == MAPTYPE_CLIENT);
-
 	try{
 		v3s16 p = blockpos + v3s16(0,0,0);
 		MapBlock *b = getBlockNoCreate(p);
@@ -7208,25 +7226,41 @@ void ClientMap::updateMeshes(v3s16 blockpos, u32 daynight_ratio)
 		b->updateMesh(daynight_ratio);
 	}
 	catch(InvalidPositionException &e){}
-	/*// Trailing edge
-	try{
-		v3s16 p = blockpos + v3s16(1,0,0);
-		MapBlock *b = getBlockNoCreate(p);
+}
+
+/*
+	Update mesh of block in which the node is, and if the node is at the
+	leading edge, update the appropriate leading blocks too.
+*/
+void ClientMap::updateNodeMeshes(v3s16 nodepos, u32 daynight_ratio)
+{
+	v3s16 dirs[4] = {
+		v3s16(0,0,0),
+		v3s16(-1,0,0),
+		v3s16(0,-1,0),
+		v3s16(0,0,-1),
+	};
+	v3s16 blockposes[4];
+	for(u32 i=0; i<4; i++)
+	{
+		v3s16 np = nodepos + dirs[i];
+		blockposes[i] = getNodeBlockPos(np);
+		// Don't update mesh of block if it has been done already
+		bool already_updated = false;
+		for(u32 j=0; j<i; j++)
+		{
+			if(blockposes[j] == blockposes[i])
+			{
+				already_updated = true;
+				break;
+			}
+		}
+		if(already_updated)
+			continue;
+		// Update mesh
+		MapBlock *b = getBlockNoCreate(blockposes[i]);
 		b->updateMesh(daynight_ratio);
 	}
-	catch(InvalidPositionException &e){}
-	try{
-		v3s16 p = blockpos + v3s16(0,1,0);
-		MapBlock *b = getBlockNoCreate(p);
-		b->updateMesh(daynight_ratio);
-	}
-	catch(InvalidPositionException &e){}
-	try{
-		v3s16 p = blockpos + v3s16(0,0,1);
-		MapBlock *b = getBlockNoCreate(p);
-		b->updateMesh(daynight_ratio);
-	}
-	catch(InvalidPositionException &e){}*/
 }
 
 void ClientMap::PrintInfo(std::ostream &out)
diff --git a/src/map.h b/src/map.h
index da2e0fcb2..74088b291 100644
--- a/src/map.h
+++ b/src/map.h
@@ -679,7 +679,7 @@ public:
 	void updateMeshes(v3s16 blockpos, u32 daynight_ratio);
 	
 	// Update meshes that touch the node
-	//void updateNodeMeshes(v3s16 nodepos, u32 daynight_ratio);
+	void updateNodeMeshes(v3s16 nodepos, u32 daynight_ratio);
 
 	// For debug printing
 	virtual void PrintInfo(std::ostream &out);
diff --git a/src/utility.cpp b/src/utility.cpp
index ed0c179e8..ae4fe435f 100644
--- a/src/utility.cpp
+++ b/src/utility.cpp
@@ -61,6 +61,17 @@ u32 TimeTaker::getTime()
 	return dtime;
 }
 
+const v3s16 g_6dirs[6] =
+{
+	// +right, +top, +back
+	v3s16( 0, 0, 1), // back
+	v3s16( 0, 1, 0), // top
+	v3s16( 1, 0, 0), // right
+	v3s16( 0, 0,-1), // front
+	v3s16( 0,-1, 0), // bottom
+	v3s16(-1, 0, 0) // left
+};
+
 const v3s16 g_26dirs[26] =
 {
 	// +right, +top, +back
diff --git a/src/utility.h b/src/utility.h
index ce43f26a3..6e14a4bb2 100644
--- a/src/utility.h
+++ b/src/utility.h
@@ -34,6 +34,8 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #include "exceptions.h"
 #include "porting.h"
 
+extern const v3s16 g_6dirs[6];
+
 extern const v3s16 g_26dirs[26];
 
 // 26th is (0,0,0)