some planets are double sided

sources/generator.cpp

@@ -16,6 +16,7 @@
 namespace unnatural
 {
 	void terrainPreseed();
+	bool terrainDoublesided();
 	Holder<Mesh> meshGenerateBaseLand();
 	Holder<Mesh> meshGenerateBaseWater();
 	Holder<Mesh> meshGenerateBaseNavigation();
@@ -74,13 +75,14 @@ namespace unnatural
 					f->writeLine(Stringizer() + "special = " + pbr);
 				if (!normal.empty())
 					f->writeLine(Stringizer() + "normal = " + normal);
+				f->writeLine("[render]");
 				if (transparency)
-				{
-					f->writeLine("[render]");
 					f->writeLine("shader = /unnatural/core/shaders/water.glsl");
-					f->writeLine("[flags]");
+				f->writeLine("[flags]");
+				if (transparency)
 					f->writeLine("transparent");
-				}
+				else if (terrainDoublesided())
+					f->writeLine("twoSided");
 				f->close();
 			}
 		};

sources/modesConfiguration.cpp

@@ -33,6 +33,8 @@ namespace unnatural
 		using ColoringFunctor = void (*)(Tile &tile);
 		ColoringFunctor coloringFnc = 0;
 
+		bool doubleSided = false;
+
 		void chooseShapeFunction()
 		{
 			static constexpr TerrainFunctor shapeModeFunctions[] = {
@@ -127,6 +129,23 @@ namespace unnatural
 				}
 				CAGE_LOG(SeverityEnum::Info, "configuration", Stringizer() + "using shape mode: '" + name + "'");
 			}
+
+			doubleSided = [&]() -> bool
+			{
+				if (name == "hexagon")
+					return true;
+				if (name == "square")
+					return true;
+				if (name == "tube")
+					return true;
+				if (name == "bowl")
+					return true;
+				if (name == "insidecube")
+					return true;
+				if (name == "twistedplane")
+					return true;
+				return false;
+			}();
 		}
 
 		void chooseElevationFunction()
@@ -290,4 +309,9 @@ namespace unnatural
 		f->writeLine(Stringizer() + "coloring: " + (String)configColoringMode);
 		f->writeLine(Stringizer() + "poles: " + (bool)configPolesEnable);
 	}
+
+	bool terrainDoublesided()
+	{
+		return doubleSided;
+	}
 }