diff --git a/include/irender.h b/include/irender.h
index 0ca70154d9..e71e886091 100644
--- a/include/irender.h
+++ b/include/irender.h
@@ -534,6 +534,11 @@ enum class RenderViewType
     OrthoView   = 1 << 1,
 };
 
+enum class BuiltInShaderType
+{
+    FlatshadeOverlay,
+};
+
 /**
  * \brief
  * The main interface for the backend renderer.
@@ -564,6 +569,12 @@ class RenderSystem
      */
     virtual ITextRenderer::Ptr captureTextRenderer(IGLFont::Style style, std::size_t size) = 0;
 
+    /**
+     * Acquire one of DarkRadiant's built-in shaders, used for drawing
+     * things like connectors, lines, points and overlays.
+     */
+    virtual ShaderPtr capture(BuiltInShaderType type) = 0;
+
     /**
      * \brief
      * Main render method.
diff --git a/radiantcore/CMakeLists.txt b/radiantcore/CMakeLists.txt
index 08f5674ad2..a170c97ce5 100644
--- a/radiantcore/CMakeLists.txt
+++ b/radiantcore/CMakeLists.txt
@@ -215,6 +215,7 @@ add_library(radiantcore MODULE
             rendersystem/backend/glprogram/GLSLBumpProgram.cpp
             rendersystem/backend/glprogram/GLSLDepthFillProgram.cpp
             rendersystem/backend/glprogram/GLSLDepthFillAlphaProgram.cpp
+            rendersystem/backend/BuiltInShader.cpp
             rendersystem/backend/OpenGLShader.cpp
             rendersystem/backend/OpenGLShaderPass.cpp
             rendersystem/backend/DepthFillPass.cpp
diff --git a/radiantcore/rendersystem/OpenGLRenderSystem.cpp b/radiantcore/rendersystem/OpenGLRenderSystem.cpp
index 5b09c6e1b6..bcf9990f89 100644
--- a/radiantcore/rendersystem/OpenGLRenderSystem.cpp
+++ b/radiantcore/rendersystem/OpenGLRenderSystem.cpp
@@ -8,6 +8,7 @@
 #include "math/Matrix4.h"
 #include "module/StaticModule.h"
 #include "backend/GLProgramFactory.h"
+#include "backend/BuiltInShader.h"
 #include "debugging/debugging.h"
 
 #include <functional>
@@ -102,7 +103,7 @@ ITextRenderer::Ptr OpenGLRenderSystem::captureTextRenderer(IGLFont::Style style,
     return existing->second;
 }
 
-ShaderPtr OpenGLRenderSystem::capture(const std::string& name)
+ShaderPtr OpenGLRenderSystem::capture(const std::string& name, const std::function<OpenGLShaderPtr()>& createShader)
 {
     // Usual ritual, check cache and return if found, otherwise create/
     // insert/return.
@@ -115,18 +116,37 @@ ShaderPtr OpenGLRenderSystem::capture(const std::string& name)
 
     // Either the shader was not found, or the weak pointer failed to lock
     // because the shader had been deleted. Either way, create a new shader
-    // and insert into the cache.
-    auto shd = std::make_shared<OpenGLShader>(name, *this);
-    _shaders[name] = shd;
+    // using the given factory functor and insert into the cache.
+    auto shader = createShader();
+    _shaders[name] = shader;
 
     // Realise the shader if the cache is realised
     if (_realised)
     {
-        shd->realise();
+        shader->realise();
     }
 
-    // Return the new shader
-    return shd;
+    return shader;
+}
+
+ShaderPtr OpenGLRenderSystem::capture(const std::string& name)
+{
+    // Forward to the method accepting our factory method
+    return capture(name, [&]()
+    { 
+        return std::make_shared<OpenGLShader>(name, *this); 
+    });
+}
+
+ShaderPtr OpenGLRenderSystem::capture(BuiltInShaderType type)
+{
+    // Forward to the method accepting our factory method
+    auto name = BuiltInShader::GetNameForType(type);
+
+    return capture(name, [&]()
+    {
+        return std::make_shared<BuiltInShader>(type, *this);
+    });
 }
 
 /*
@@ -262,13 +282,10 @@ void OpenGLRenderSystem::realise()
         _glProgramFactory->realise();
     }
 
-    // Realise the OpenGLShader objects
-    for (ShaderMap::iterator i = _shaders.begin(); i != _shaders.end(); ++i)
+    // Realise all shaders
+    for (auto& [_, shader] : _shaders)
     {
-        OpenGLShaderPtr sp = i->second;
-        assert(sp);
-
-        sp->realise();
+        shader->realise();
     }
 }
 
@@ -280,13 +297,10 @@ void OpenGLRenderSystem::unrealise()
 
     _realised = false;
 
-    // Unrealise the OpenGLShader objects
-    for (ShaderMap::iterator i = _shaders.begin(); i != _shaders.end(); ++i)
+    // Unrealise all OpenGLShader objects
+    for (auto& [_, shader] : _shaders)
     {
-        OpenGLShaderPtr sp = i->second;
-        assert(sp);
-
-        sp->unrealise();
+        shader->unrealise();
     }
 
 	if (GlobalOpenGLContext().getSharedContext() && 
diff --git a/radiantcore/rendersystem/OpenGLRenderSystem.h b/radiantcore/rendersystem/OpenGLRenderSystem.h
index 9dbc09a953..f87716b0ed 100644
--- a/radiantcore/rendersystem/OpenGLRenderSystem.h
+++ b/radiantcore/rendersystem/OpenGLRenderSystem.h
@@ -24,8 +24,7 @@ class OpenGLRenderSystem
   public OpenGLStateManager
 {
 	// Map of named Shader objects
-	typedef std::map<std::string, OpenGLShaderPtr> ShaderMap;
-	ShaderMap _shaders;
+    std::map<std::string, OpenGLShaderPtr> _shaders;
 
 	// whether this module has been realised
 	bool _realised;
@@ -68,6 +67,7 @@ class OpenGLRenderSystem
     ITextRenderer::Ptr captureTextRenderer(IGLFont::Style style, std::size_t size) override;
 
 	ShaderPtr capture(const std::string& name) override;
+    ShaderPtr capture(BuiltInShaderType type) override;
 	void render(RenderViewType renderViewType, RenderStateFlags globalstate,
                 const Matrix4& modelview,
                 const Matrix4& projection,
@@ -108,6 +108,9 @@ class OpenGLRenderSystem
     virtual const StringSet& getDependencies() const override;
     virtual void initialiseModule(const IApplicationContext& ctx) override;
     virtual void shutdownModule() override;
+
+private:
+    ShaderPtr capture(const std::string& name, const std::function<OpenGLShaderPtr()>& createShader);
 };
 typedef std::shared_ptr<OpenGLRenderSystem> OpenGLRenderSystemPtr;
 
diff --git a/radiantcore/rendersystem/backend/BuiltInShader.cpp b/radiantcore/rendersystem/backend/BuiltInShader.cpp
new file mode 100644
index 0000000000..199e825858
--- /dev/null
+++ b/radiantcore/rendersystem/backend/BuiltInShader.cpp
@@ -0,0 +1,19 @@
+#include "BuiltInShader.h"
+
+#include "string/convert.h"
+
+namespace render
+{
+
+BuiltInShader::BuiltInShader(BuiltInShaderType type, OpenGLRenderSystem& renderSystem) :
+    OpenGLShader(GetNameForType(type), renderSystem)
+{}
+
+
+
+std::string BuiltInShader::GetNameForType(BuiltInShaderType type)
+{
+    return "$BUILT_IN_SHADER[" + string::to_string(static_cast<std::size_t>(type)) + "]";
+}
+
+}
diff --git a/radiantcore/rendersystem/backend/BuiltInShader.h b/radiantcore/rendersystem/backend/BuiltInShader.h
new file mode 100644
index 0000000000..0dc61c9148
--- /dev/null
+++ b/radiantcore/rendersystem/backend/BuiltInShader.h
@@ -0,0 +1,17 @@
+#pragma once
+
+#include "OpenGLShader.h"
+
+namespace render
+{
+
+class BuiltInShader :
+    public OpenGLShader
+{
+public:
+    BuiltInShader(BuiltInShaderType type, OpenGLRenderSystem& renderSystem);
+
+    static std::string GetNameForType(BuiltInShaderType type);
+};
+
+}
diff --git a/radiantcore/rendersystem/backend/OpenGLShader.cpp b/radiantcore/rendersystem/backend/OpenGLShader.cpp
index bb79fc2a4d..19d40524db 100644
--- a/radiantcore/rendersystem/backend/OpenGLShader.cpp
+++ b/radiantcore/rendersystem/backend/OpenGLShader.cpp
@@ -79,7 +79,6 @@ OpenGLRenderSystem& OpenGLShader::getRenderSystem()
 void OpenGLShader::destroy()
 {
     _enabledViewTypes = 0;
-    _vertexBuffer.reset();
     _materialChanged.disconnect();
     _material.reset();
     _shaderPasses.clear();
@@ -141,7 +140,7 @@ void OpenGLShader::drawSurfaces(const VolumeTest& view)
 
 bool OpenGLShader::hasSurfaces() const
 {
-    return !_geometryRenderer.empty() || !_surfaceRenderer.empty() || _vertexBuffer && _vertexBuffer->getNumVertices() > 0;
+    return !_geometryRenderer.empty() || !_surfaceRenderer.empty();
 }
 
 IGeometryRenderer::Slot OpenGLShader::addGeometry(GeometryType indexType,
diff --git a/radiantcore/rendersystem/backend/OpenGLShader.h b/radiantcore/rendersystem/backend/OpenGLShader.h
index ca96e9d8c3..81ff08276e 100644
--- a/radiantcore/rendersystem/backend/OpenGLShader.h
+++ b/radiantcore/rendersystem/backend/OpenGLShader.h
@@ -5,7 +5,6 @@
 #include "irender.h"
 #include "ishaders.h"
 #include "string/string.h"
-#include "render/IndexedVertexBuffer.h"
 #include "render/WindingRenderer.h"
 #include "GeometryRenderer.h"
 #include "SurfaceRenderer.h"
@@ -21,7 +20,7 @@ class OpenGLRenderSystem;
 /**
  * Implementation of the Shader class.
  */
-class OpenGLShader final :
+class OpenGLShader :
 	public Shader
 {
 private:
@@ -48,8 +47,6 @@ class OpenGLShader final :
 	typedef std::set<Observer*> Observers;
 	Observers _observers;
 
-    std::unique_ptr<render::IndexedVertexBuffer<ArbitraryMeshVertex>> _vertexBuffer;
-
     std::unique_ptr<IBackendWindingRenderer> _windingRenderer;
     GeometryRenderer _geometryRenderer;
     SurfaceRenderer _surfaceRenderer;
@@ -99,7 +96,7 @@ class OpenGLShader final :
     /// Construct and initialise
     OpenGLShader(const std::string& name, OpenGLRenderSystem& renderSystem);
 
-    ~OpenGLShader();
+    virtual ~OpenGLShader();
 
     // Returns the owning render system
     OpenGLRenderSystem& getRenderSystem();
@@ -111,7 +108,6 @@ class OpenGLShader final :
 					   const LightSources* lights,
                        const IRenderEntity* entity) override;
 
-    //void addSurface(const std::vector<ArbitraryMeshVertex>& vertices, const std::vector<unsigned int>& indices) override;
     bool hasSurfaces() const;
     void drawSurfaces(const VolumeTest& view);
 
@@ -143,11 +139,7 @@ class OpenGLShader final :
 
 	bool isRealised() override;
 
-	/**
-	 * Realise this shader
-	 */
 	void realise();
-
 	void unrealise();
 
 	// Return the Material used by this shader
diff --git a/tools/msvc/DarkRadiantCore.vcxproj b/tools/msvc/DarkRadiantCore.vcxproj
index 88d823c080..0428862ddb 100644
--- a/tools/msvc/DarkRadiantCore.vcxproj
+++ b/tools/msvc/DarkRadiantCore.vcxproj
@@ -622,6 +622,7 @@
     <ClCompile Include="..\..\radiantcore\log\StringLogDevice.cpp" />
     <ClCompile Include="..\..\radiantcore\modulesystem\ModuleLoader.cpp" />
     <ClCompile Include="..\..\radiantcore\modulesystem\ModuleRegistry.cpp" />
+    <ClCompile Include="..\..\radiantcore\rendersystem\backend\BuiltInShader.cpp" />
     <ClCompile Include="..\..\radiantcore\rendersystem\backend\DepthFillPass.cpp" />
     <ClCompile Include="..\..\radiantcore\rendersystem\backend\GLProgramFactory.cpp" />
     <ClCompile Include="..\..\radiantcore\rendersystem\backend\glprogram\GenericVFPProgram.cpp" />
@@ -979,6 +980,7 @@
     <ClInclude Include="..\..\radiantcore\messagebus\MessageBus.h" />
     <ClInclude Include="..\..\radiantcore\modulesystem\ModuleLoader.h" />
     <ClInclude Include="..\..\radiantcore\modulesystem\ModuleRegistry.h" />
+    <ClInclude Include="..\..\radiantcore\rendersystem\backend\BuiltInShader.h" />
     <ClInclude Include="..\..\radiantcore\rendersystem\backend\DepthFillPass.h" />
     <ClInclude Include="..\..\radiantcore\rendersystem\backend\GeometryRenderer.h" />
     <ClInclude Include="..\..\radiantcore\rendersystem\backend\GLProgramFactory.h" />
diff --git a/tools/msvc/DarkRadiantCore.vcxproj.filters b/tools/msvc/DarkRadiantCore.vcxproj.filters
index 78e850ef59..07c5875603 100644
--- a/tools/msvc/DarkRadiantCore.vcxproj.filters
+++ b/tools/msvc/DarkRadiantCore.vcxproj.filters
@@ -1114,6 +1114,9 @@
     <ClCompile Include="..\..\radiantcore\entity\RenderableEntityName.cpp">
       <Filter>src\entity</Filter>
     </ClCompile>
+    <ClCompile Include="..\..\radiantcore\rendersystem\backend\BuiltInShader.cpp">
+      <Filter>src\rendersystem\backend</Filter>
+    </ClCompile>
   </ItemGroup>
   <ItemGroup>
     <ClInclude Include="..\..\radiantcore\modulesystem\ModuleLoader.h">
@@ -2280,5 +2283,8 @@
     <ClInclude Include="..\..\radiantcore\entity\RenderableEntityName.h">
       <Filter>src\entity</Filter>
     </ClInclude>
+    <ClInclude Include="..\..\radiantcore\rendersystem\backend\BuiltInShader.h">
+      <Filter>src\rendersystem\backend</Filter>
+    </ClInclude>
   </ItemGroup>
 </Project>
\ No newline at end of file