diff --git a/raymarcher.cc b/raymarcher.cc
index c7b2ed4..d1b8db7 100644
--- a/raymarcher.cc
+++ b/raymarcher.cc
@@ -50,6 +50,7 @@ void T_Raymarcher::render( )
 		U_NEAR_PLANE		= 5 ,
 		U_RAYMARCHER		= 6 ,
 		U_FOG			= 7 ,
+		U_CORRECTION		= 8
 	};
 
 	const auto id( program_.program( E_ShaderType::FRAGMENT ) );
@@ -64,6 +65,7 @@ void T_Raymarcher::render( )
 	glProgramUniform4f( id , U_RAYMARCHER , rmIterations , rmStep ,
 			rmEpsilon , rmMaxDist );
 	glProgramUniform1f( id , U_FOG , fog );
+	glProgramUniform1i( id , U_CORRECTION , correction_ );
 
 	glDrawArrays( GL_TRIANGLE_STRIP , 0 , 4 );
 
@@ -83,6 +85,7 @@ void T_Raymarcher::makeUI( )
 				-10 , -0.5 , "10 ^ %.2f" ) ) {
 			rmEpsilon = pow( 10 , epsLog );
 		}
+		ImGui::DragInt( "Correction" , &correction_ , .001 , 0 , 50 );
 		ImGui::DragFloat( "Fog" , &fog , .000001 , 0 , 1 , "%.5f" );
 	}
 }
diff --git a/raymarcher.hh b/raymarcher.hh
index a315638..9386682 100644
--- a/raymarcher.hh
+++ b/raymarcher.hh
@@ -35,8 +35,9 @@ struct T_Raymarcher
 
 	int rmIterations = 256;
 	float rmStep = 1.2;
-	float rmEpsilon = .001;
+	float rmEpsilon = .00001;
 	float rmMaxDist = 250;
 	float fog = .00015;
+	int correction_ = 10;
 	float epsLog = log( rmEpsilon ) / log( 10 );
 };
diff --git a/shaders/chunks/raymarcher.glsl b/shaders/chunks/raymarcher.glsl
index 016bce2..a11a929 100644
--- a/shaders/chunks/raymarcher.glsl
+++ b/shaders/chunks/raymarcher.glsl
@@ -8,6 +8,7 @@ layout( location = 4 ) uniform vec3 u_CamUp;
 layout( location = 5 ) uniform float u_NearPlane;
 layout( location = 6 ) uniform vec4 u_Render;
 layout( location = 7 ) uniform float u_FogAttenuation;
+layout( location = 8 ) uniform int u_Correction;
 
 layout( location = 0 ) out vec3 o_Color;
 layout( location = 1 ) out float o_Z;
diff --git a/shaders/scene.f.glsl b/shaders/scene.f.glsl
index 1609ed8..90c9bf6 100644
--- a/shaders/scene.f.glsl
+++ b/shaders/scene.f.glsl
@@ -58,8 +58,8 @@ vec2 RM_Map( vec3 pos )
 		sin( 1 ) , cos( 1 ) );
 	return vec2( mix( box( q , vec3( 1.5 ) ) ,
 				length( q ) - 1.5 ,
-				.5 ) ,
-			step( 0. , 1.9 - length( pos.xy ) ) );
+				.35 ) ,
+			step( 0. , 3 - length( pos.xy ) ) );
 }
 
 
@@ -105,7 +105,7 @@ void main( )
 	if ( r.y >= 0. ) {
 		const vec3 hitPos = RM_ReduceDiscontinuity(
 				u_CamPos , rayDir , r.x ,
-				tanPhi , 10 );
+				tanPhi , u_Correction );
 		const vec3 normal = RM_GetNormal( hitPos );
 
 		const int midx = int( r.y );