diff --git a/include/ShaderLayer.h b/include/ShaderLayer.h
index 834abd58c7..62b48b6cd1 100644
--- a/include/ShaderLayer.h
+++ b/include/ShaderLayer.h
@@ -93,6 +93,7 @@ class ShaderLayer
 		TEXGEN_REFLECT		= 1 << 1,
 		TEXGEN_SKYBOX		= 1 << 2,
 		TEXGEN_WOBBLESKY	= 1 << 3,
+		TEXGEN_SCREEN	    = 1 << 4, // screen aligned, for mirrorRenders and screen space temporaries
 	};
 
     /**
@@ -212,6 +213,12 @@ class ShaderLayer
      */
     virtual CubeMapMode getCubeMapMode() const = 0;
 
+    /**
+     * Returns the dimensions specifying the map size for 
+     * stages using the "mirrorRenderMap", "remoteRenderMap" keywords.
+     */
+    virtual const Vector2& getRenderMapSize() = 0;
+
 	/**
 	 * Returns the value of the scale expressions of this stage.
 	 */
diff --git a/radiantcore/shaders/Doom3ShaderLayer.cpp b/radiantcore/shaders/Doom3ShaderLayer.cpp
index 2a1bdf99c5..8f6cb7ff10 100644
--- a/radiantcore/shaders/Doom3ShaderLayer.cpp
+++ b/radiantcore/shaders/Doom3ShaderLayer.cpp
@@ -226,6 +226,16 @@ void Doom3ShaderLayer::setMapType(MapType type)
     _mapType = type;
 }
 
+const Vector2& Doom3ShaderLayer::getRenderMapSize()
+{
+    return _renderMapSize;
+}
+
+void Doom3ShaderLayer::setRenderMapSize(const Vector2& size)
+{
+    _renderMapSize = size;
+}
+
 bool Doom3ShaderLayer::hasAlphaTest() const
 {
     return _alphaTest != REG_ZERO;
diff --git a/radiantcore/shaders/Doom3ShaderLayer.h b/radiantcore/shaders/Doom3ShaderLayer.h
index a4347a2c0f..84aff4e4e6 100644
--- a/radiantcore/shaders/Doom3ShaderLayer.h
+++ b/radiantcore/shaders/Doom3ShaderLayer.h
@@ -113,6 +113,8 @@ class Doom3ShaderLayer
     // Stage-specific polygon offset, is 0 if not used
     float _privatePolygonOffset;
 
+    Vector2 _renderMapSize;
+
 public:
 
     // Constructor
@@ -130,6 +132,9 @@ class Doom3ShaderLayer
     MapType getMapType() const override;
     void setMapType(MapType type);
 
+    const Vector2& getRenderMapSize() override;
+    void setRenderMapSize(const Vector2& size);
+
     bool hasAlphaTest() const override;
     float getAlphaTest() const override;
 
diff --git a/radiantcore/shaders/ShaderTemplate.cpp b/radiantcore/shaders/ShaderTemplate.cpp
index 624714f2f4..7ab678f990 100644
--- a/radiantcore/shaders/ShaderTemplate.cpp
+++ b/radiantcore/shaders/ShaderTemplate.cpp
@@ -615,8 +615,9 @@ bool ShaderTemplate::parseBlendMaps(parser::DefTokeniser& tokeniser, const std::
 
 		try
 		{
-			std::stoi(tokeniser.nextToken());
-			std::stoi(tokeniser.nextToken());
+			auto width = std::stoi(tokeniser.nextToken());
+            auto height = std::stoi(tokeniser.nextToken());
+            _currentLayer->setRenderMapSize(Vector2(width, height));
 		}
 		catch (std::logic_error& e)
 		{
@@ -627,11 +628,13 @@ bool ShaderTemplate::parseBlendMaps(parser::DefTokeniser& tokeniser, const std::
 	else if (token == "mirrorrendermap")
 	{
         _currentLayer->setMapType(ShaderLayer::MapType::MirrorRenderMap);
+        _currentLayer->setTexGenType(ShaderLayer::TexGenType::TEXGEN_SCREEN);
 
 		try
 		{
-			std::stoi(tokeniser.nextToken());
-			std::stoi(tokeniser.nextToken());
+            auto width = std::stoi(tokeniser.nextToken());
+            auto height = std::stoi(tokeniser.nextToken());
+            _currentLayer->setRenderMapSize(Vector2(width, height));
 		}
 		catch (std::invalid_argument& e)
 		{