diff --git a/README.md b/README.md
new file mode 100644
index 000000000..f04f324f7
--- /dev/null
+++ b/README.md
@@ -0,0 +1,22 @@
+# Welcome to GZDoom!
+
+[![Build Status](https://ci.appveyor.com/api/projects/status/github/coelckers/gzdoom?branch=master&svg=true)](https://ci.appveyor.com/project/coelckers/gzdoom) [![Build Status](https://travis-ci.org/coelckers/gzdoom.svg?branch=master)](https://travis-ci.org/coelckers/gzdoom)
+
+## GZDoom is a modder-friendly OpenGL source port based on the DOOM engine
+
+Copyright (c) 1998-2018 ZDoom + GZDoom teams, and contributors
+
+Doom Source (c) 1997 id Software, Raven Software, and contributors
+
+Please see license files for individual contributor licenses
+
+Special thanks to Coraline of the 3DGE team for allowing us to use her README.md as a template for this one.
+
+### Licensed under the GPL v3 (or greater)
+##### https://www.gnu.org/licenses/quick-guide-gplv3.en.html
+---
+
+## How to build GZDoom
+
+To build GZDoom, please see the [wiki](https://zdoom.org/wiki/) and see the "Programmer's Corner" on the bottom-right corner of the page to build for your platform.
+
diff --git a/src/g_level.cpp b/src/g_level.cpp
index 0b211f3e6..17f76a67d 100644
--- a/src/g_level.cpp
+++ b/src/g_level.cpp
@@ -2028,6 +2028,10 @@ DEFINE_FIELD(FLevelLocals, F1Pic)
 DEFINE_FIELD(FLevelLocals, maptype)
 DEFINE_FIELD(FLevelLocals, Music)
 DEFINE_FIELD(FLevelLocals, musicorder)
+DEFINE_FIELD(FLevelLocals, skytexture1)
+DEFINE_FIELD(FLevelLocals, skytexture2)
+DEFINE_FIELD(FLevelLocals, skyspeed1)
+DEFINE_FIELD(FLevelLocals, skyspeed2)
 DEFINE_FIELD(FLevelLocals, total_secrets)
 DEFINE_FIELD(FLevelLocals, found_secrets)
 DEFINE_FIELD(FLevelLocals, total_items)
@@ -2093,3 +2097,19 @@ CCMD(skyfog)
 	}
 }
 
+
+//==========================================================================
+//
+// ZScript counterpart to ACS ChangeSky, uses TextureIDs
+//
+//==========================================================================
+DEFINE_ACTION_FUNCTION(FLevelLocals, ChangeSky)
+{
+	PARAM_SELF_STRUCT_PROLOGUE(FLevelLocals);
+	PARAM_INT(sky1);
+	PARAM_INT(sky2);
+	sky1texture = self->skytexture1 = FSetTextureID(sky1);
+	sky2texture = self->skytexture2 = FSetTextureID(sky2);
+	R_InitSkyMap();
+	return 0;
+}
diff --git a/src/gl/renderer/gl_postprocess.cpp b/src/gl/renderer/gl_postprocess.cpp
index 142358af6..463895e8c 100644
--- a/src/gl/renderer/gl_postprocess.cpp
+++ b/src/gl/renderer/gl_postprocess.cpp
@@ -161,12 +161,13 @@ void FGLRenderer::RenderScreenQuad()
 	GLRenderer->mVBO->RenderArray(GL_TRIANGLE_STRIP, FFlatVertexBuffer::PRESENT_INDEX, 4);
 }
 
-void FGLRenderer::PostProcessScene(int fixedcm)
+void FGLRenderer::PostProcessScene(int fixedcm, const std::function<void()> &afterBloomDrawEndScene2D)
 {
 	mBuffers->BlitSceneToTexture();
 	UpdateCameraExposure();
 	mCustomPostProcessShaders->Run("beforebloom");
 	BloomScene(fixedcm);
+	afterBloomDrawEndScene2D();
 	TonemapScene();
 	ColormapScene(fixedcm);
 	LensDistortScene();
diff --git a/src/gl/renderer/gl_renderer.h b/src/gl/renderer/gl_renderer.h
index 8b6ba46df..eb71cd4be 100644
--- a/src/gl/renderer/gl_renderer.h
+++ b/src/gl/renderer/gl_renderer.h
@@ -7,6 +7,7 @@
 #include "r_renderer.h"
 #include "r_data/matrix.h"
 #include "gl/dynlights/gl_shadowmap.h"
+#include <functional>
 
 struct particle_t;
 class FCanvasTexture;
@@ -43,6 +44,7 @@ class F2DDrawer;
 class FHardwareTexture;
 class FShadowMapShader;
 class FCustomPostProcessShaders;
+class GLSceneDrawer;
 
 inline float DEG2RAD(float deg)
 {
@@ -174,7 +176,7 @@ public:
 	void RenderView(player_t* player);
 
 	void RenderScreenQuad();
-	void PostProcessScene(int fixedcm);
+	void PostProcessScene(int fixedcm, const std::function<void()> &afterBloomDrawEndScene2D);
 	void AmbientOccludeScene();
 	void UpdateCameraExposure();
 	void BloomScene(int fixedcm);
diff --git a/src/gl/renderer/gl_renderstate.cpp b/src/gl/renderer/gl_renderstate.cpp
index 2405aff09..119444af6 100644
--- a/src/gl/renderer/gl_renderstate.cpp
+++ b/src/gl/renderer/gl_renderstate.cpp
@@ -177,6 +177,7 @@ bool FRenderState::ApplyShader()
 	activeShader->muAlphaThreshold.Set(mAlphaThreshold);
 	activeShader->muLightIndex.Set(mLightIndex);	// will always be -1 for now
 	activeShader->muClipSplit.Set(mClipSplit);
+	activeShader->muViewHeight.Set(viewheight);
 
 	if (mGlowEnabled)
 	{
diff --git a/src/gl/scene/gl_scene.cpp b/src/gl/scene/gl_scene.cpp
index bbead7737..a0bcb4882 100644
--- a/src/gl/scene/gl_scene.cpp
+++ b/src/gl/scene/gl_scene.cpp
@@ -681,10 +681,29 @@ void GLSceneDrawer::EndDrawScene(sector_t * viewsector)
 
 	Reset3DViewport();
 
-	// [BB] Only draw the sprites if we didn't render a HUD model before.
-	if ( renderHUDModel == false )
+	// Delay drawing psprites until after bloom has been applied, if enabled.
+	if (!FGLRenderBuffers::IsEnabled() || !gl_bloom || FixedColormap != CM_DEFAULT)
 	{
-		DrawPlayerSprites (viewsector, false);
+		DrawEndScene2D(viewsector);
+	}
+	else
+	{
+		// Restore standard rendering state
+		gl_RenderState.BlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
+		gl_RenderState.ResetColor();
+		gl_RenderState.EnableTexture(true);
+		glDisable(GL_SCISSOR_TEST);
+	}
+}
+
+void GLSceneDrawer::DrawEndScene2D(sector_t * viewsector)
+{
+	const bool renderHUDModel = gl_IsHUDModelForPlayerAvailable(players[consoleplayer].camera->player);
+
+	// [BB] Only draw the sprites if we didn't render a HUD model before.
+	if (renderHUDModel == false)
+	{
+		DrawPlayerSprites(viewsector, false);
 	}
 	if (gl.legacyMode)
 	{
@@ -706,7 +725,6 @@ void GLSceneDrawer::EndDrawScene(sector_t * viewsector)
 	glDisable(GL_SCISSOR_TEST);
 }
 
-
 //-----------------------------------------------------------------------------
 //
 // R_RenderView - renders one view - either the screen or a camera texture
@@ -846,7 +864,7 @@ sector_t * GLSceneDrawer::RenderViewpoint (AActor * camera, GL_IRECT * bounds, f
 		if (mainview && toscreen) EndDrawScene(lviewsector); // do not call this for camera textures.
 		if (mainview && FGLRenderBuffers::IsEnabled())
 		{
-			GLRenderer->PostProcessScene(FixedColormap);
+			GLRenderer->PostProcessScene(FixedColormap, [&]() { if (gl_bloom && FixedColormap == CM_DEFAULT) DrawEndScene2D(lviewsector); });
 
 			// This should be done after postprocessing, not before.
 			GLRenderer->mBuffers->BindCurrentFB();
diff --git a/src/gl/scene/gl_scenedrawer.h b/src/gl/scene/gl_scenedrawer.h
index 9209e6dad..9ade64b73 100644
--- a/src/gl/scene/gl_scenedrawer.h
+++ b/src/gl/scene/gl_scenedrawer.h
@@ -55,6 +55,7 @@ public:
 	void ProcessScene(bool toscreen = false);
 	void DrawBlend(sector_t * viewsector);
 	void EndDrawScene(sector_t * viewsector);
+	void DrawEndScene2D(sector_t * viewsector);
 	void RenderActorsInPortal(FGLLinePortal *glport);
 
 	void CheckViewArea(vertex_t *v1, vertex_t *v2, sector_t *frontsector, sector_t *backsector);
diff --git a/src/gl/scene/gl_sprite.cpp b/src/gl/scene/gl_sprite.cpp
index edd0da1d9..e287c7215 100644
--- a/src/gl/scene/gl_sprite.cpp
+++ b/src/gl/scene/gl_sprite.cpp
@@ -73,7 +73,7 @@ CVAR(Bool, gl_billboard_particles, true, CVAR_ARCHIVE | CVAR_GLOBALCONFIG)
 CVAR(Int, gl_enhanced_nv_stealth, 3, CVAR_ARCHIVE | CVAR_GLOBALCONFIG)
 CUSTOM_CVAR(Int, gl_fuzztype, 0, CVAR_ARCHIVE)
 {
-	if (self < 0 || self > 7) self = 0;
+	if (self < 0 || self > 8) self = 0;
 }
 
 EXTERN_CVAR (Float, transsouls)
diff --git a/src/gl/shaders/gl_shader.cpp b/src/gl/shaders/gl_shader.cpp
index d551106a4..4af1ef5a1 100644
--- a/src/gl/shaders/gl_shader.cpp
+++ b/src/gl/shaders/gl_shader.cpp
@@ -254,6 +254,7 @@ bool FShader::Load(const char * name, const char * vert_prog_lump, const char *
 	muClipHeight.Init(hShader, "uClipHeight");
 	muClipHeightDirection.Init(hShader, "uClipHeightDirection");
 	muAlphaThreshold.Init(hShader, "uAlphaThreshold");
+	muViewHeight.Init(hShader, "uViewHeight");
 	muTimer.Init(hShader, "timer");
 
 	lights_index = glGetUniformLocation(hShader, "lights");
@@ -392,6 +393,7 @@ static const FDefaultShader defaultshaders[]=
 	{"Jagged Fuzz", "shaders/glsl/fuzz_jagged.fp"},
 	{"Noise Fuzz", "shaders/glsl/fuzz_noise.fp"},
 	{"Smooth Noise Fuzz", "shaders/glsl/fuzz_smoothnoise.fp"},
+	{"Software Fuzz", "shaders/glsl/fuzz_software.fp"},
 	{NULL,NULL}
 };
 
diff --git a/src/gl/shaders/gl_shader.h b/src/gl/shaders/gl_shader.h
index f41f7467b..6265d62a9 100644
--- a/src/gl/shaders/gl_shader.h
+++ b/src/gl/shaders/gl_shader.h
@@ -284,6 +284,7 @@ class FShader
 	FBufferedUniform1f muClipHeight;
 	FBufferedUniform1f muClipHeightDirection;
 	FBufferedUniform1f muAlphaThreshold;
+	FBufferedUniform1i muViewHeight;
 	FBufferedUniform1f muTimer;
 	
 	int lights_index;
@@ -397,7 +398,7 @@ public:
 	}
 };
 
-#define FIRST_USER_SHADER 12
+#define FIRST_USER_SHADER 13
 
 enum
 {
diff --git a/src/gl/stereo3d/gl_stereo_cvars.cpp b/src/gl/stereo3d/gl_stereo_cvars.cpp
index 201e33590..47b7ff217 100644
--- a/src/gl/stereo3d/gl_stereo_cvars.cpp
+++ b/src/gl/stereo3d/gl_stereo_cvars.cpp
@@ -32,6 +32,7 @@
 #include "gl/stereo3d/gl_sidebyside3d.h"
 #include "gl/stereo3d/gl_interleaved3d.h"
 #include "gl/system/gl_cvars.h"
+#include "version.h"
 
 // Set up 3D-specific console variables:
 CVAR(Int, vr_mode, 0, CVAR_GLOBALCONFIG)
@@ -42,7 +43,10 @@ CVAR(Bool, vr_swap_eyes, false, CVAR_GLOBALCONFIG)
 // For broadest GL compatibility, require user to explicitly enable quad-buffered stereo mode.
 // Setting vr_enable_quadbuffered_stereo does not automatically invoke quad-buffered stereo,
 // but makes it possible for subsequent "vr_mode 7" to invoke quad-buffered stereo
-CVAR(Bool, vr_enable_quadbuffered, false, CVAR_ARCHIVE | CVAR_GLOBALCONFIG)
+CUSTOM_CVAR(Bool, vr_enable_quadbuffered, false, CVAR_ARCHIVE | CVAR_GLOBALCONFIG)
+{
+	Printf("You must restart " GAMENAME " to switch quad stereo mode\n");
+}
 
 // intraocular distance in meters
 CVAR(Float, vr_ipd, 0.062f, CVAR_ARCHIVE|CVAR_GLOBALCONFIG) // METERS
diff --git a/src/p_acs.cpp b/src/p_acs.cpp
index e2fccad14..3e5358a3c 100644
--- a/src/p_acs.cpp
+++ b/src/p_acs.cpp
@@ -9852,7 +9852,7 @@ scriptwait:
 			if (STACK(2) != 0)
 			{
 				AActor *marine;
-				NActorIterator iterator("ScriptedMarine", STACK(2));
+				NActorIterator iterator(NAME_ScriptedMarine, STACK(2));
 
 				while ((marine = iterator.Next()) != NULL)
 				{
@@ -9861,7 +9861,7 @@ scriptwait:
 			}
 			else
 			{
-				if (activator != nullptr && activator->IsKindOf (PClass::FindClass("ScriptedMarine")))
+				if (activator != nullptr && activator->IsKindOf (NAME_ScriptedMarine))
 				{
 					SetMarineWeapon(activator, STACK(1));
 				}
@@ -9878,7 +9878,7 @@ scriptwait:
 					if (STACK(2) != 0)
 					{
 						AActor *marine;
-						NActorIterator iterator("ScriptedMarine", STACK(2));
+						NActorIterator iterator(NAME_ScriptedMarine, STACK(2));
 
 						while ((marine = iterator.Next()) != NULL)
 						{
@@ -9887,7 +9887,7 @@ scriptwait:
 					}
 					else
 					{
-						if (activator != nullptr && activator->IsKindOf("ScriptedMarine"))
+						if (activator != nullptr && activator->IsKindOf(NAME_ScriptedMarine))
 						{
 							SetMarineSprite(activator, type);
 						}
diff --git a/src/p_sectors.cpp b/src/p_sectors.cpp
index 369c5de61..fb4789e17 100644
--- a/src/p_sectors.cpp
+++ b/src/p_sectors.cpp
@@ -1659,7 +1659,7 @@ DEFINE_ACTION_FUNCTION(_Sector, NextLowestFloorAt)
 	 PARAM_SELF_STRUCT_PROLOGUE(sector_t);
 	 PARAM_INT(pos);
 	 PARAM_FLOAT(o);
-	 self->SetXScale(pos, o);
+	 self->SetYScale(pos, o);
 	 return 0;
  }
 
diff --git a/src/p_trace.cpp b/src/p_trace.cpp
index d00a5c4cc..fd79861ec 100644
--- a/src/p_trace.cpp
+++ b/src/p_trace.cpp
@@ -955,8 +955,8 @@ static bool EditTraceResult (uint32_t flags, FTraceResults &res)
 //  [ZZ] here go the methods for the ZScript interface
 //
 //==========================================================================
-IMPLEMENT_CLASS(DTracer, false, false)
-DEFINE_FIELD_X(Tracer, DTracer, Results)
+IMPLEMENT_CLASS(DLineTracer, false, false)
+DEFINE_FIELD(DLineTracer, Results)
 
 // define TraceResults fields
 DEFINE_FIELD_NAMED_X(TraceResults, FTraceResults, Sector, HitSector)
@@ -978,9 +978,9 @@ DEFINE_FIELD_X(TraceResults, FTraceResults, CrossedWaterPos)
 DEFINE_FIELD_X(TraceResults, FTraceResults, Crossed3DWater)
 DEFINE_FIELD_X(TraceResults, FTraceResults, Crossed3DWaterPos)
 
-DEFINE_ACTION_FUNCTION(DTracer, Trace)
+DEFINE_ACTION_FUNCTION(DLineTracer, Trace)
 {
-	PARAM_SELF_PROLOGUE(DTracer);
+	PARAM_SELF_PROLOGUE(DLineTracer);
 	/*bool Trace(const DVector3 &start, sector_t *sector, const DVector3 &direction, double maxDist,
 	ActorFlags ActorMask, uint32_t WallMask, AActor *ignore, FTraceResults &res, uint32_t traceFlags = 0,
 	ETraceStatus(*callback)(FTraceResults &res, void *) = NULL, void *callbackdata = NULL);*/
@@ -1001,13 +1001,13 @@ DEFINE_ACTION_FUNCTION(DTracer, Trace)
 
 	// Trace(vector3 start, Sector sector, vector3 direction, double maxDist, ETraceFlags traceFlags)
 	bool res = Trace(DVector3(start_x, start_y, start_z), sector, DVector3(direction_x, direction_y, direction_z), maxDist,
-					 (ActorFlag)0xFFFFFFFF, 0xFFFFFFFF, nullptr, self->Results, traceFlags, &DTracer::TraceCallback, self);
+					 (ActorFlag)0xFFFFFFFF, 0xFFFFFFFF, nullptr, self->Results, traceFlags, &DLineTracer::TraceCallback, self);
 	ACTION_RETURN_BOOL(res);
 }
 
-ETraceStatus DTracer::TraceCallback(FTraceResults& res, void* pthis)
+ETraceStatus DLineTracer::TraceCallback(FTraceResults& res, void* pthis)
 {
-	DTracer* self = (DTracer*)pthis;
+	DLineTracer* self = (DLineTracer*)pthis;
 	// "res" here should refer to self->Results anyway.
 
 	// patch results a bit. modders don't expect it to work like this most likely.
@@ -1036,13 +1036,13 @@ ETraceStatus DTracer::TraceCallback(FTraceResults& res, void* pthis)
 	return self->CallZScriptCallback();
 }
 
-ETraceStatus DTracer::CallZScriptCallback()
+ETraceStatus DLineTracer::CallZScriptCallback()
 {
-	IFVIRTUAL(DTracer, TraceCallback)
+	IFVIRTUAL(DLineTracer, TraceCallback)
 	{
 		int status;
 		VMReturn results[1] = { &status };
-		VMValue params[1] = { (DTracer*)this };
+		VMValue params[1] = { (DLineTracer*)this };
 		VMCall(func, params, 1, results, 1);
 		return (ETraceStatus)status;
 	}
diff --git a/src/p_trace.h b/src/p_trace.h
index af4187f78..0a61cc725 100644
--- a/src/p_trace.h
+++ b/src/p_trace.h
@@ -113,9 +113,9 @@ bool Trace(const DVector3 &start, sector_t *sector, const DVector3 &direction, d
 	ETraceStatus(*callback)(FTraceResults &res, void *) = NULL, void *callbackdata = NULL);
 
 // [ZZ] this is the object that's used for ZScript
-class DTracer : public DObject
+class DLineTracer : public DObject
 {
-	DECLARE_CLASS(DTracer, DObject)
+	DECLARE_CLASS(DLineTracer, DObject)
 public:
 	FTraceResults Results;
 	static ETraceStatus TraceCallback(FTraceResults& res, void* pthis);
diff --git a/wadsrc/static/language.enu b/wadsrc/static/language.enu
index 7b5eed9a0..501436552 100644
--- a/wadsrc/static/language.enu
+++ b/wadsrc/static/language.enu
@@ -2729,7 +2729,7 @@ GLPREFMNU_AMBLIGHT 				= "Ambient light level";
 GLPREFMNU_RENDERQUALITY 		= "Rendering quality";
 GLPREFMNU_MENUBLUR				= "Menu Blur";
 GLPREFMNU_VRMODE 				= "Stereo 3D VR";
-GLPREFMNU_VRQUADSTEREO 			= "Enable Quad Stereo (Requires Restart)";
+GLPREFMNU_VRQUADSTEREO 			= "Enable Quad Stereo";
 GLPREFMNU_MULTISAMPLE			= "Multisample";
 GLPREFMNU_TONEMAP				= "Tonemap Mode";
 GLPREFMNU_BLOOM					= "Bloom effect";
diff --git a/wadsrc/static/menudef.txt b/wadsrc/static/menudef.txt
index 3c727247f..6e02c1d5e 100644
--- a/wadsrc/static/menudef.txt
+++ b/wadsrc/static/menudef.txt
@@ -2120,6 +2120,7 @@ OptionValue "FuzzStyle"
 	4, "$OPTVAL_TRANSLUCENTFUZZ"
 	6, "$OPTVAL_NOISE"
 	7, "$OPTVAL_SMOOTHNOISE"
+	8, "$OPTVAL_SOFTWARE"
 	//5, "$OPTVAL_JAGGEDFUZZ" I can't see any difference between this and 4 so it's disabled for now.
 }
 
diff --git a/wadsrc/static/shaders/glsl/fuzz_software.fp b/wadsrc/static/shaders/glsl/fuzz_software.fp
new file mode 100644
index 000000000..b17b49b8a
--- /dev/null
+++ b/wadsrc/static/shaders/glsl/fuzz_software.fp
@@ -0,0 +1,52 @@
+// Fuzz effect as rendered by the software renderer
+uniform float timer;
+
+#define FUZZTABLE 50
+#define FUZZ_RANDOM_X_SIZE 100
+#define FRACBITS 16
+#define fixed_t int
+
+int fuzz_random_x_offset[FUZZ_RANDOM_X_SIZE] = int[]
+(
+	75, 76, 21, 91, 56, 33, 62, 99, 61, 79,
+	95, 54, 41, 18, 69, 43, 49, 59, 10, 84,
+	94, 17, 57, 46,  9, 39, 55, 34,100, 81,
+	73, 88, 92,  3, 63, 36,  7, 28, 13, 80,
+	16, 96, 78, 29, 71, 58, 89, 24,  1, 35,
+	52, 82,  4, 14, 22, 53, 38, 66, 12, 72,
+	90, 44, 77, 83,  6, 27, 48, 30, 42, 32,
+	65, 15, 97, 20, 67, 74, 98, 85, 60, 68,
+	19, 26,  8, 87, 86, 64, 11, 37, 31, 47,
+	25,  5, 50, 51, 23,  2, 93, 70, 40, 45
+);
+
+int fuzzoffset[FUZZTABLE] = int[]
+(
+	 6, 11,  6, 11,  6,  6, 11,  6,  6, 11,
+	 6,  6,  6, 11,  6,  6,  6, 11, 15, 18,
+	21,  6, 11, 15,  6,  6,  6,  6, 11, 6,
+	11,  6,  6, 11, 15,  6,  6, 11, 15, 18,
+	21,  6,  6,  6,  6, 11,  6,  6, 11, 6
+);
+
+vec4 ProcessTexel()
+{
+	vec2 texCoord = vTexCoord.st;
+	vec4 basicColor = getTexel(texCoord);
+
+	// Ideally fuzzpos would be an uniform and differ from each sprite so that overlapping demons won't get the same shade for the same pixel
+	int next_random = int(abs(mod(timer * 35.0, float(FUZZ_RANDOM_X_SIZE))));
+	int fuzzpos = (/*fuzzpos +*/ fuzz_random_x_offset[next_random] * FUZZTABLE / 100) % FUZZTABLE;
+
+	int x = int(gl_FragCoord.x);
+	int y = int(gl_FragCoord.y);
+
+	fixed_t fuzzscale = (200 << FRACBITS) / uViewHeight;
+	int scaled_x = (x * fuzzscale) >> FRACBITS;
+	int fuzz_x = fuzz_random_x_offset[scaled_x % FUZZ_RANDOM_X_SIZE] + fuzzpos;
+	fixed_t fuzzcount = FUZZTABLE << FRACBITS;
+	fixed_t fuzz = ((fuzz_x << FRACBITS) + y * fuzzscale) % fuzzcount;
+	float alpha = float(fuzzoffset[fuzz >> FRACBITS]) / 32.0;
+
+	return vec4(0.0, 0.0, 0.0, basicColor.a * alpha);
+}
diff --git a/wadsrc/static/shaders/glsl/shaderdefs.i b/wadsrc/static/shaders/glsl/shaderdefs.i
index c8fcf7b6b..15d68428e 100644
--- a/wadsrc/static/shaders/glsl/shaderdefs.i
+++ b/wadsrc/static/shaders/glsl/shaderdefs.i
@@ -48,6 +48,9 @@ uniform float uGlobVis; // uGlobVis = R_GetGlobVis(r_visibility) / 32.0
 // dynamic lights
 uniform int uLightIndex;
 
+// Software fuzz scaling
+uniform int uViewHeight;
+
 // quad drawer stuff
 #ifdef USE_QUAD_DRAWER
 uniform mat4 uQuadVertices;
diff --git a/wadsrc/static/zscript/base.txt b/wadsrc/static/zscript/base.txt
index 12be10d64..d2c923b39 100644
--- a/wadsrc/static/zscript/base.txt
+++ b/wadsrc/static/zscript/base.txt
@@ -524,7 +524,7 @@ struct TraceResults native
 	native vector3 Crossed3DWaterPos;
 }
 
-class Tracer : Object native
+class LineTracer : Object native
 {
 	native @TraceResults Results;
 	native bool Trace(vector3 start, Sector sec, vector3 direction, double maxDist, ETraceFlags traceFlags);
@@ -591,6 +591,10 @@ struct LevelLocals native
 	native readonly int maptype;
 	native readonly String Music;
 	native readonly int musicorder;
+	native readonly TextureID skytexture1;
+	native readonly TextureID skytexture2;
+	native float skyspeed1;
+	native float skyspeed2;
 	native int total_secrets;
 	native int found_secrets;
 	native int total_items;
@@ -640,8 +644,10 @@ struct LevelLocals native
 	native static clearscope vector3 Vec3Diff(vector3 v1, vector3 v2);
 
 	native clearscope String GetChecksum() const;
-	
-	clearscope String TimeFormatted(bool totals = false)
+
+	native void ChangeSky( TextureID sky1, TextureID sky2 );
+
+	String clearscope TimeFormatted(bool totals = false)
 	{
 		int sec = Thinker.Tics2Seconds(totals? totaltime : time); 
 		return String.Format("%02d:%02d:%02d", sec / 3600, (sec % 3600) / 60, sec % 60);