diff --git a/src/p_sectors.cpp b/src/p_sectors.cpp
index c2488b998..c7a502354 100644
--- a/src/p_sectors.cpp
+++ b/src/p_sectors.cpp
@@ -1307,6 +1307,84 @@ int side_t::GetLightLevel (bool foggy, int baselight, bool is3dlight, int *pfake
 	return baselight;
 }
 
+DEFINE_ACTION_FUNCTION(_Secplane, isSlope)
+{
+	PARAM_SELF_STRUCT_PROLOGUE(secplane_t);
+	ACTION_RETURN_BOOL(!self->normal.XY().isZero());
+}
+
+DEFINE_ACTION_FUNCTION(_Secplane, PointOnSide)
+{
+	PARAM_SELF_STRUCT_PROLOGUE(secplane_t);
+	PARAM_FLOAT(x);
+	PARAM_FLOAT(y);
+	PARAM_FLOAT(z);
+	ACTION_RETURN_INT(self->PointOnSide(DVector3(x, y, z)));
+}
+
+DEFINE_ACTION_FUNCTION(_Secplane, ZatPoint)
+{
+	PARAM_SELF_STRUCT_PROLOGUE(secplane_t);
+	PARAM_FLOAT(x);
+	PARAM_FLOAT(y);
+	ACTION_RETURN_FLOAT(self->ZatPoint(x, y));
+}
+
+DEFINE_ACTION_FUNCTION(_Secplane, ZatPointDist)
+{
+	PARAM_SELF_STRUCT_PROLOGUE(secplane_t);
+	PARAM_FLOAT(x);
+	PARAM_FLOAT(y);
+	PARAM_FLOAT(d);
+	ACTION_RETURN_FLOAT((d + self->normal.X*x + self->normal.Y*y) * self->negiC);
+}
+
+DEFINE_ACTION_FUNCTION(_Secplane, isEqual)
+{
+	PARAM_SELF_STRUCT_PROLOGUE(secplane_t);
+	PARAM_POINTER(other, secplane_t);
+	ACTION_RETURN_BOOL(*self == *other);
+}
+
+DEFINE_ACTION_FUNCTION(_Secplane, ChangeHeight)
+{
+	PARAM_SELF_STRUCT_PROLOGUE(secplane_t);
+	PARAM_FLOAT(hdiff);
+	self->ChangeHeight(hdiff);
+	return 0;
+}
+
+DEFINE_ACTION_FUNCTION(_Secplane, GetChangedHeight)
+{
+	PARAM_SELF_STRUCT_PROLOGUE(secplane_t);
+	PARAM_FLOAT(hdiff);
+	ACTION_RETURN_FLOAT(self->GetChangedHeight(hdiff));
+}
+
+DEFINE_ACTION_FUNCTION(_Secplane, HeightDiff)
+{
+	PARAM_SELF_STRUCT_PROLOGUE(secplane_t);
+	PARAM_FLOAT(oldd);
+	if (numparam == 2)
+	{
+		ACTION_RETURN_FLOAT(self->HeightDiff(oldd));
+	}
+	else
+	{
+		PARAM_FLOAT(newd);
+		ACTION_RETURN_FLOAT(self->HeightDiff(oldd, newd));
+	}
+}
+
+DEFINE_ACTION_FUNCTION(_Secplane, PointToDist)
+{
+	PARAM_SELF_STRUCT_PROLOGUE(secplane_t);
+	PARAM_FLOAT(x);
+	PARAM_FLOAT(y);
+	PARAM_FLOAT(z);
+	ACTION_RETURN_FLOAT(self->PointToDist(DVector2(x, y), z));
+}
+
 
 DEFINE_FIELD_X(Sector, sector_t, floorplane)
 DEFINE_FIELD_X(Sector, sector_t, ceilingplane)
@@ -1366,3 +1444,7 @@ DEFINE_FIELD_X(Line, line_t, backsector)
 DEFINE_FIELD_X(Line, line_t, validcount)
 DEFINE_FIELD_X(Line, line_t, locknumber)
 DEFINE_FIELD_X(Line, line_t, portalindex)
+
+DEFINE_FIELD_X(Secplane, secplane_t, normal)
+DEFINE_FIELD_X(Secplane, secplane_t, D)
+DEFINE_FIELD_X(Secplane, secplane_t, negiC)
diff --git a/src/scripting/thingdef_data.cpp b/src/scripting/thingdef_data.cpp
index 2e37030bf..2e9654607 100644
--- a/src/scripting/thingdef_data.cpp
+++ b/src/scripting/thingdef_data.cpp
@@ -711,6 +711,26 @@ static int fieldcmp(const void * a, const void * b)
 void InitThingdef()
 {
 	// Create all global variables here because this cannot be done on the script side and really isn't worth adding support for.
+	// Also create all special fields here that cannot be declared by script syntax.
+
+	auto secplanestruct = NewNativeStruct("Secplane", nullptr);
+	secplanestruct->Size = sizeof(secplane_t);
+	secplanestruct->Align = alignof(secplane_t);
+	auto sectorstruct = NewNativeStruct("Sector", nullptr);
+	sectorstruct->Size = sizeof(sector_t);
+	sectorstruct->Align = alignof(sector_t);
+
+
+	// set up the lines array in the sector struct. This is a bit messy because the type system is not prepared to handle a pointer to an array of pointers to a native struct even remotely well...
+	// As a result, the size has to be set to something large and arbritrary because it can change between maps. This will need some serious improvement when things get cleaned up.
+	sectorstruct->AddNativeField("lines", NewPointer(NewResizableArray(NewPointer(NewNativeStruct("line", nullptr), false)), false), myoffsetof(sector_t, Lines), VARF_Native);
+
+	// add the sector planes. These are value items of native structs so they have to be done here.
+	sectorstruct->AddNativeField("ceilingplane", secplanestruct, myoffsetof(sector_t, ceilingplane), VARF_Native);
+	sectorstruct->AddNativeField("floorplane", secplanestruct, myoffsetof(sector_t, floorplane), VARF_Native);
+
+
+
 
 	// expose the global validcount variable.
 	PField *vcf = new PField("validcount", TypeSInt32, VARF_Native | VARF_Static, (intptr_t)&validcount);
@@ -725,10 +745,12 @@ void InitThingdef()
 	PField *levelf = new PField("level", lstruct, VARF_Native | VARF_Static, (intptr_t)&level);
 	GlobalSymbols.AddSymbol(levelf);
 
+	// Add the sector array to LevelLocals.
+	lstruct->AddNativeField("sectors", NewPointer(NewResizableArray(sectorstruct), false), myoffsetof(FLevelLocals, sectors), VARF_Native);
+
 	// set up a variable for the DEH data
 	PStruct *dstruct = NewNativeStruct("DehInfo", nullptr);
 	PField *dehf = new PField("deh", dstruct, VARF_Native | VARF_Static, (intptr_t)&deh);
-
 	GlobalSymbols.AddSymbol(dehf);
 
 	// set up a variable for the global players array.
@@ -739,17 +761,6 @@ void InitThingdef()
 	PField *playerf = new PField("players", parray, VARF_Native | VARF_Static, (intptr_t)&players);
 	GlobalSymbols.AddSymbol(playerf);
 
-	// set up the lines array in the sector struct. This is a bit messy because the type system is not prepared to handle a pointer to an array of pointers to a native struct even remotely well...
-	// As a result, the size has to be set to something large and arbritrary because it can change between maps. This will need some serious improvement when things get cleaned up.
-	pstruct = NewNativeStruct("Sector", nullptr);
-	pstruct->AddNativeField("lines", NewPointer(NewResizableArray(NewPointer(NewNativeStruct("line", nullptr), false)), false), myoffsetof(sector_t, Lines), VARF_Native);
-
-	// Add the sector array to LevelLocals.
-	pstruct->Size = sizeof(sector_t);
-	pstruct->Align = alignof(sector_t);
-	parray = NewArray(pstruct, MAXPLAYERS);
-	lstruct->AddNativeField("sectors", NewPointer(NewResizableArray(pstruct), false), myoffsetof(FLevelLocals, sectors), VARF_Native);
-
 	parray = NewArray(TypeBool, MAXPLAYERS);
 	playerf = new PField("playeringame", parray, VARF_Native | VARF_Static | VARF_ReadOnly, (intptr_t)&playeringame);
 	GlobalSymbols.AddSymbol(playerf);
diff --git a/wadsrc/static/zscript/base.txt b/wadsrc/static/zscript/base.txt
index 23a830537..be161483e 100644
--- a/wadsrc/static/zscript/base.txt
+++ b/wadsrc/static/zscript/base.txt
@@ -236,10 +236,27 @@ struct Line native
 	native readonly uint			portalindex;
 }
 
+struct SecPlane native
+{
+	native Vector3 Normal;
+	native double D;
+	native double negiC;
+	
+	native bool isSlope();
+	native int PointOnSide(Vector3 pos);
+	native double ZatPoint (Vector2 v);
+	native double ZatPointDist(Vector2 v, double dist);
+	native bool isEqual(Secplane other);
+	native void ChangeHeight(double hdiff);
+	native double GetChangedHeight(double hdiff);
+	native double HeightDiff(double oldd, double newd = 0.0);
+	native double PointToDist(const DVector2 &xy, double z);
+}
+
 struct Sector native
 {
-	//secplane_t	floorplane, ceilingplane;
-	//FDynamicColormap *ColorMap;	// [RH] Per-sector colormap
+	//secplane_t	floorplane, ceilingplane;	// defined internally
+	//FDynamicColormap *ColorMap;
 
 	native Actor 		SoundTarget;