diff --git a/README.md b/README.md
index 7482cca1..c4cac0d4 100644
--- a/README.md
+++ b/README.md
@@ -1,3 +1,29 @@
+Diamondtest
+===========
+This repository is a port of [spheretest](https://github.com/Jeija/spheretest) by [Jeija](https://github.com/Jeija) to the latest version of Minetest. There are bugs, help wanted!!
+
+Original **`README`**:
+In order to compile spheretest for your platform, follow the minetest-specific instructions below.
+I also recommend you to get `minetest_game` and your favorite mods for the standard minetest experience.
+Then, create a file `minetest.conf` and add the following lines to it:
+
+```
+planet_enable = true
+planet_radius = 2
+planet_keep_scale = true
+planet_centrifugal_enable = true
+planet_realistic_gravity = true
+movement_gravity = 10
+enable_clouds = 0
+active_block_range = 4
+active_object_send_range_blocks = 4
+viewing_range = 400
+```
+
+You can tweak these settings and see how they affect the planet's appearance and behaviour.
+In the game, create a new world with Mapgen "flat". The planet edges are very glitchy, so anything other than "flat" won't look good.
+Keep in mind that this is only a technical demo and not intended to be a full-featured game.
+
 Minetest
 ========
 
diff --git a/src/clientenvironment.cpp b/src/clientenvironment.cpp
index 5b865872..f9d3cbfa 100644
--- a/src/clientenvironment.cpp
+++ b/src/clientenvironment.cpp
@@ -178,7 +178,6 @@ void ClientEnvironment::step(float dtime)
 				// the height will actually be the magnitude of the complex exponential function
 				if (g_settings->getBool("planet_keep_scale"))
 					height = planet_radius * exp(lplayer->getPosition().Y / planet_radius);
-				float blockwidth = height / planet_radius;
 
 				if (g_settings->getBool("planet_enable") && g_settings->getBool("planet_realistic_gravity")) {
 					if (lplayer->getPosition().Y < 0)
@@ -187,13 +186,13 @@ void ClientEnvironment::step(float dtime)
 						gravity_coeff = (planet_radius * planet_radius) / (height * height);
 				}
 
- 				if(lplayer->in_liquid == false)
+				if(lplayer->in_liquid == false)
 					speed.Y -= gravity_coeff * lplayer->movement_gravity * lplayer->physics_override_gravity * dtime_part * 2; 
 				
 				// Planet: Apply centrifugal force
 				// a_z = v^2 / height with v = (horizontal speed) * (block width at that height)
 				if (g_settings->getBool("planet_enable") && g_settings->getBool("planet_centrifugal_enable") && lplayer->in_liquid == false)
-					speed.Y += (speed.X * speed.X + speed.Z * speed.Z) * blockwidth * blockwidth / height * dtime_part * 2;
+					speed.Y += (speed.X * speed.X + speed.Z * speed.Z) / height * dtime_part * 2;
 
 				// Liquid floating / sinking
 				if(lplayer->in_liquid && !lplayer->swimming_vertical)
diff --git a/src/collision.cpp b/src/collision.cpp
index d824f5b8..7ef73849 100644
--- a/src/collision.cpp
+++ b/src/collision.cpp
@@ -274,10 +274,10 @@ collisionMoveResult collisionMoveSimple(Environment *env, IGameDef *gamedef,
 
 	int planet_circumference = ceil(g_settings->getU16("planet_radius") * M_PI) * 2 * MAP_BLOCKSIZE;
 
-	v3s16 p;
-	for (p.X = min.X; p.X <= max.X; p.X++)
-	for (p.Y = min.Y; p.Y <= max.Y; p.Y++)
-	for (p.Z = min.Z; p.Z <= max.Z; p.Z++) {
+	for (s16 x = min.X; x <= max.X; x++)
+	for (s16 y = min.Y; y <= max.Y; y++)
+	for (s16 z = min.Z; z <= max.Z; z++) {
+		v3s16 p(x,y,z);
 		if (g_settings->getBool("planet_enable")) {
 			if (p.X >= planet_circumference / 2) p.X -= planet_circumference;
 			if (p.Z >= planet_circumference / 2) p.Z -= planet_circumference;