diff --git a/LICENSE.txt b/LICENSE.txt
index d9550727a4..7dcefde92c 100644
--- a/LICENSE.txt
+++ b/LICENSE.txt
@@ -37,7 +37,7 @@ in particular, let us know and we can try to clarify it.
     BSD
 
   /build/premake/*.lua
-    MIT
+    MIT - see license_mit.txt
 
   /docs
     Various (unspecified)
@@ -49,7 +49,7 @@ in particular, let us know and we can try to clarify it.
     GPL version 2 (or later) - see license_gpl-2.0.txt
 
   /source/lib
-    MIT
+    MIT - see license_mit.txt
 
   /source/scriptinterface/third_party
     MPL 2.0
@@ -60,16 +60,16 @@ in particular, let us know and we can try to clarify it.
   /source/third_party/encryption
     GPL version 2 (or later)
     ISC (pkcs5_pbkdf2.cpp)
-    MIT (pkcs5_pbkdf2.h)
+    MIT (pkcs5_pbkdf2.h) - see license_mit.txt
 
   /source/third-party/jsonspirit
-    MIT
+    MIT - see license_mit.txt
 
   /source/third_party/mikktspace
     zlib
 
   /source/third_party/mongoose
-    MIT
+    MIT - see license_mit.txt
 
   /source/third_party/tinygettext
     zlib
@@ -79,3 +79,6 @@ in particular, let us know and we can try to clarify it.
 
   /source/tools/atlas
     GPL version 2 (or later) - see license_gpl-2.0.txt
+
+  /binaries/data/mods/public/globalscripts/BicubicInterpolation.js
+    MIT 2013 Hugh Kennedy - see license_mit.txt
diff --git a/binaries/data/mods/public/globalscripts/BicubicInterpolation.js b/binaries/data/mods/public/globalscripts/BicubicInterpolation.js
new file mode 100644
index 0000000000..b21f3b5a09
--- /dev/null
+++ b/binaries/data/mods/public/globalscripts/BicubicInterpolation.js
@@ -0,0 +1,47 @@
+/**
+ * From https://github.com/hughsk/bicubic licensed under MIT 2013 Hugh Kennedy - see /license_mit.txt
+ * Two dimensional interpolation within a square grid using polynomials of 3rd degree.
+ * @param {float} xf - X coordinate within the subgrid (see below) of the point to interpolate the value for
+ * @param {float} yf - y coordinate within the subgrid (see below) of the point to interpolate the value for
+ * @param {float} p00 - Value of the property to calculate at the origin of the naighbor grid
+ * @param {float} pxy - Value at naighbor grid coordinates x/y, x/y in {0, 1, 2, 3}
+ * @return {float} - Value at the given float coordinates in the small grid interpolated from it's values
+  */
+function bicubicInterpolation(
+	xf, yf,
+	p00, p01, p02, p03,
+	p10, p11, p12, p13,
+	p20, p21, p22, p23,
+	p30, p31, p32, p33
+)
+{
+	var yf2 = yf * yf;
+	var xf2 = xf * xf;
+	var xf3 = xf * xf2;
+
+	var x00 = p03 - p02 - p00 + p01;
+	var x01 = p00 - p01 - x00;
+	var x02 = p02 - p00;
+	var x0 = x00*xf3 + x01*xf2 + x02*xf + p01;
+
+	var x10 = p13 - p12 - p10 + p11;
+	var x11 = p10 - p11 - x10;
+	var x12 = p12 - p10;
+	var x1 = x10*xf3 + x11*xf2 + x12*xf + p11;
+
+	var x20 = p23 - p22 - p20 + p21;
+	var x21 = p20 - p21 - x20;
+	var x22 = p22 - p20;
+	var x2 = x20*xf3 + x21*xf2 + x22*xf + p21;
+
+	var x30 = p33 - p32 - p30 + p31;
+	var x31 = p30 - p31 - x30;
+	var x32 = p32 - p30;
+	var x3 = x30*xf3 + x31*xf2 + x32*xf + p31;
+
+	var y0 = x3 - x2 - x0 + x1;
+	var y1 = x0 - x1 - y0;
+	var y2 = x2 - x0;
+
+	return y0*yf*yf2 + y1*yf2 + y2*yf + x1;
+}
diff --git a/binaries/data/mods/public/maps/random/rmgen2/gaia.js b/binaries/data/mods/public/maps/random/rmgen2/gaia.js
index b22a4d47f1..3dfe64c4cd 100644
--- a/binaries/data/mods/public/maps/random/rmgen2/gaia.js
+++ b/binaries/data/mods/public/maps/random/rmgen2/gaia.js
@@ -1274,43 +1274,51 @@ function getRandomDeviation(base, deviation)
  * @param heightmap - An array with a square number of heights
  * @param tilemap - The IDs of the palletmap to be painted for each heightmap tile
  * @param pallet - The tile texture names used by the tilemap.
- * @returns the ratio of heightmap tiles per map size tiles
+ * @return the ratio of heightmap tiles per map size tiles
  */
 function paintHeightmap(heightmap, tilemap, pallet, func = undefined)
 {
-	let lastI = -1;
-	let mapSize = getMapSize();
+	let mapSize = getMapSize(); // Width of the map in terrain tiles
 	let hmSize = Math.sqrt(heightmap.length);
-	let scale = hmSize / mapSize;
+	let scale = hmSize / (mapSize + 1); // There are mapSize + 1 vertices (each 1 tile is surrounded by 2x2 vertices)
 
-	for (let y = 0; y < mapSize; ++y)
-		for (let x = 0; x < mapSize; ++x)
+	for (let x = 0; x <= mapSize; ++x)
+		for (let y = 0; y <= mapSize; ++y)
 		{
-			let i = Math.floor(x * scale) * hmSize + Math.floor(y * scale);
+			let hmPoint = { "x": x * scale, "y": y * scale };
+			let hmTile = { "x": Math.floor(hmPoint.x), "y": Math.floor(hmPoint.y) };
+			let shift = { "x": 0, "y": 0 };
 
-			let height = heightmap[i];
-			let tile = pallet[tilemap[i]];
+			if (hmTile.x == 0)
+				shift.x = 1;
+			else if (hmTile.x == hmSize - 1)
+				shift.x = - 2;
+			else if (hmTile.x == hmSize - 2)
+				shift.x = - 1;
 
-			if (i == lastI)
+			if (hmTile.y == 0)
+				shift.y = 1;
+			else if (hmTile.y == hmSize - 1)
+				shift.y = - 2;
+			else if (hmTile.y == hmSize - 2)
+				shift.y = - 1;
+
+			let neighbors = [];
+			for (let localYi = 0; localYi < 4; ++localYi)
+				for (let localXi = 0; localXi < 4; ++localXi)
+					neighbors.push(heightmap[(hmTile.x + localXi + shift.x - 1) * hmSize + (hmTile.y + localYi + shift.y - 1)]);
+
+			setHeight(x, y, bicubicInterpolation(hmPoint.x - hmTile.x - shift.x, hmPoint.y - hmTile.y - shift.y, ...neighbors) / scale);
+
+			if (x < mapSize && y < mapSize)
 			{
-				let nearby = [i];
+				let i = hmTile.x * hmSize + hmTile.y;
+				let tile = pallet[tilemap[i]];
+				placeTerrain(x, y, tile);
 
-				if (i + hmSize < heightmap.length)
-				{
-					nearby.push(i + hmSize);
-					height = (heightmap[nearby[0]] + heightmap[nearby[1]]) / 2;
-				}
-
-				tile = pallet[tilemap[nearby[randInt(0, nearby.length - 1)]]];
+				if (func)
+					func(tile, x, y);
 			}
-
-			setHeight(x, y, height / scale);
-			placeTerrain(x, y, tile);
-
-			if (func)
-				func(tile, x, y);
-
-			lastI = i;
 		}
 
 	return scale;
diff --git a/license_mit.txt b/license_mit.txt
new file mode 100644
index 0000000000..8b9abce10c
--- /dev/null
+++ b/license_mit.txt
@@ -0,0 +1,19 @@
+The MIT License (MIT)
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+THE SOFTWARE.