diff --git a/doomsday/apps/client/src/render/rend_main.cpp b/doomsday/apps/client/src/render/rend_main.cpp
index ac19677209..78ece71ed3 100644
--- a/doomsday/apps/client/src/render/rend_main.cpp
+++ b/doomsday/apps/client/src/render/rend_main.cpp
@@ -757,7 +757,7 @@ ClientMaterial *Rend_ChooseMapSurfaceMaterial(Surface const &surface)
                     }
                     else if (&surface == &side.top())
                     {
-                        return static_cast<ClientMaterial *>(side.sector().ceiling().surface().materialPtr());
+                        static_cast<ClientMaterial *>(side.sector().ceiling().surface().materialPtr());
                     }
                 }
             }
@@ -3118,8 +3118,8 @@ static void writeSubspaceSkyMaskStrips(SkyFixEdge::FixType fixType)
             bool endStrip = false;
             if (hedge->hasMapElement())
             {
-                scanMaterialOffset += hedge->mapElementAs<LineSideSegment>().length()
-                                    * (direction == Anticlockwise? -1 : 1);
+                scanMaterialOffset += hedge->mapElementAs<LineSideSegment>().length() *
+                                      (direction == Anticlockwise ? -1 : 1);
 
                 // Prepare the edge geometry
                 SkyFixEdge skyEdge(*hedge, fixType, (direction == Anticlockwise)? Line::From : Line::To,
diff --git a/doomsday/apps/client/src/render/skyfixedge.cpp b/doomsday/apps/client/src/render/skyfixedge.cpp
index fcbdbe147b..f0756ab28a 100644
--- a/doomsday/apps/client/src/render/skyfixedge.cpp
+++ b/doomsday/apps/client/src/render/skyfixedge.cpp
@@ -28,6 +28,7 @@
 #include "Plane"
 #include "Sector"
 #include "Surface"
+#include "MaterialAnimator"
 
 #include "render/rend_main.h"
 
@@ -124,6 +125,9 @@ DENG2_PIMPL(SkyFixEdge)
         // Only edges with line segments need fixes.
         if (!hedge->hasMapElement()) return false;
 
+        const auto &lineSeg  = hedge->mapElementAs<LineSideSegment>();
+        const auto &lineSide = lineSeg.lineSide();
+
         auto const *space     = &hedge->face().mapElementAs<ConvexSubspace>();
         auto const *backSpace = hedge->twin().hasFace() ? &hedge->twin().face().mapElementAs<ConvexSubspace>()
                                                         : nullptr;
@@ -135,6 +139,15 @@ DENG2_PIMPL(SkyFixEdge)
         if (backSubsec && &backSubsec->sector() == &subsec->sector())
             return false;
 
+        if (lineSide.middle().hasMaterial() &&
+            !lineSide.middle().materialAnimator()->isOpaque() &&
+            ((!lower && !lineSide.top().hasMaterial()) ||
+             (lower  && !lineSide.bottom().hasMaterial())))
+        {
+            // Icarus: force fields render hack
+            return false;
+        }
+
         // Select the relative planes for the fix type.
         dint relPlane = lower ? Sector::Floor : Sector::Ceiling;
         Plane const *front   = &subsec->visPlane(relPlane);
@@ -143,7 +156,6 @@ DENG2_PIMPL(SkyFixEdge)
         if (!front->surface().hasSkyMaskedMaterial())
             return false;
 
-        LineSide const &lineSide = hedge->mapElementAs<LineSideSegment>().lineSide();
         bool const hasClosedBack = R_SideBackClosed(lineSide);
 
         if (!devRendSkyMode)
diff --git a/doomsday/apps/client/src/render/walledge.cpp b/doomsday/apps/client/src/render/walledge.cpp
index fbdf30b90d..7f3c99db7b 100644
--- a/doomsday/apps/client/src/render/walledge.cpp
+++ b/doomsday/apps/client/src/render/walledge.cpp
@@ -29,7 +29,7 @@
 #include "world/maputil.h"
 #include "world/surface.h"
 #include "client/clientsubsector.h"
-
+#include "MaterialAnimator"
 #include "render/rend_main.h"  /// devRendSkyMode @todo remove me
 
 #include "Face"
@@ -342,6 +342,10 @@ struct WallEdge::Impl : public IHPlane
                 LineSide const &lineSide = seg.lineSide();
                 Surface const &middle    = lineSide.middle();
 
+                const bool isExtendedMasked = middle.hasMaterial() &&
+                                              !middle.materialAnimator()->isOpaque() &&
+                                              !lineSide.top().hasMaterial();
+
                 if (!line.isSelfReferencing() && ffloor == &subsec.sector().floor())
                 {
                     lo = de::max(bfloor->heightSmoothed(), ffloor->heightSmoothed());