- fixed: Due to the default skybox being moved to the global level data, there was insufficient information to distinguish between using the default skybox or the regular sky. Fixed by adding two new sector flags which get set by a 0-tid SkyPicker.

src/g_shared/a_skies.cpp

@@ -186,10 +186,12 @@ void ASkyPicker::PostBeginPlay ()
 		if (0 == (args[1] & 2))
 		{
 			Sector->CeilingSkyBox = box;
+			if (box == NULL) Sector->MoreFlags |= SECF_NOCEILINGSKYBOX;	// sector should ignore the level's default skybox
 		}
 		if (0 == (args[1] & 1))
 		{
 			Sector->FloorSkyBox = box;
+			if (box == NULL) Sector->MoreFlags |= SECF_NOFLOORSKYBOX;	// sector should ignore the level's default skybox
 		}
 	}
 	Destroy ();

src/p_sectors.cpp

@@ -29,6 +29,7 @@
 #include "po_man.h"
 #include "farchive.h"
 #include "r_utility.h"
+#include "a_sharedglobal.h"
 #include "r_data/colormaps.h"
 
 
@@ -800,6 +801,20 @@ int sector_t::GetCeilingLight () const
 	}
 }
 
+
+ASkyViewpoint *sector_t::GetSkyBox(int which)
+{
+	if (which == floor)
+	{
+		return FloorSkyBox != NULL ? FloorSkyBox : (MoreFlags & SECF_NOFLOORSKYBOX)? (ASkyViewpoint*)NULL : level.DefaultSkybox;
+	}
+	else
+	{
+		return CeilingSkyBox != NULL ? CeilingSkyBox : (MoreFlags & SECF_NOCEILINGSKYBOX)? (ASkyViewpoint*)NULL : level.DefaultSkybox;
+	}
+}
+
+
 sector_t *sector_t::GetHeightSec() const 
 {
 	if (heightsec == NULL)

src/r_bsp.cpp

@@ -1087,7 +1087,8 @@ void R_Subsector (subsector_t *sub)
 		basecolormap = frontsector->ColorMap;
 	}
 
-	skybox = frontsector->CeilingSkyBox != NULL ? frontsector->CeilingSkyBox : level.DefaultSkybox;
+	skybox = frontsector->GetSkyBox(sector_t::ceiling);
+
 	ceilingplane = frontsector->ceilingplane.PointOnSide(viewx, viewy, viewz) > 0 ||
 		frontsector->GetTexture(sector_t::ceiling) == skyflatnum ||
 		(skybox != NULL && skybox->bAlways) ||
@@ -1127,7 +1128,7 @@ void R_Subsector (subsector_t *sub)
 	// killough 3/7/98: Add (x,y) offsets to flats, add deep water check
 	// killough 3/16/98: add floorlightlevel
 	// killough 10/98: add support for skies transferred from sidedefs
-	skybox = frontsector->FloorSkyBox != NULL ? frontsector->FloorSkyBox : level.DefaultSkybox;
+	skybox = frontsector->GetSkyBox(sector_t::floor);
 	floorplane = frontsector->floorplane.PointOnSide(viewx, viewy, viewz) > 0 || // killough 3/7/98
 		frontsector->GetTexture(sector_t::floor) == skyflatnum ||
 		(skybox != NULL && skybox->bAlways) ||

src/r_defs.h

@@ -340,6 +340,8 @@ enum
 	SECF_UNDERWATERMASK	= 32+64,
 	SECF_DRAWN			= 128,	// sector has been drawn at least once
 	SECF_HIDDEN			= 256,	// Do not draw on textured automap
+	SECF_NOFLOORSKYBOX	= 512,	// force use of regular sky 
+	SECF_NOCEILINGSKYBOX	= 1024,	// force use of regular sky 
 };
 
 enum
@@ -451,6 +453,8 @@ struct sector_t
 	DInterpolation *SetInterpolation(int position, bool attach);
 	void StopInterpolation(int position);
 
+	ASkyViewpoint *GetSkyBox(int which);
+
 	enum
 	{
 		floor,