diff --git a/main/Scene-load.cc b/main/Scene-load.cc
index af1c1b0..48f9c73 100644
--- a/main/Scene-load.cc
+++ b/main/Scene-load.cc
@@ -57,6 +57,10 @@ void Scene::processNode(refptr<Node> node)
     {
         processTransformBlock(node);
     }
+    else if ( typeid(*node) == typeid(MaterialDefinitionNode) )
+    {
+        processMaterialDefinition(node);
+    }
     else
     {
         cerr << __FILE__ << ": " << __LINE__
@@ -183,8 +187,38 @@ void Scene::processTransformBlock(refptr<Node> node)
     m_transforms.pop();
 }
 
+void Scene::processMaterialDefinition(refptr<Node> node)
+{
+    map< string, refptr<Material> >::iterator it =
+        m_materials.find(node->getString());
+    if ( it == m_materials.end() )
+    {
+        m_materials[node->getString()] = processMaterial(node);
+    }
+    else
+    {
+        cerr << "Error: duplicate material definition for material '"
+             << node->getString() << "'" << endl;
+        exit(4);
+    }
+}
+
 refptr<Material> Scene::processMaterial(refptr<Node> node)
 {
+    if ( typeid(*node) == typeid(MaterialRefNode) )
+    {
+        map< string, refptr<Material> >::iterator it =
+            m_materials.find(node->getString());
+        if ( it == m_materials.end() )
+        {
+            cerr << "Undefined material '" << node->getString()
+                 << "' requested!" << endl;
+            exit(4);
+        }
+
+        return m_materials[node->getString()];
+    }
+
     refptr<Material> material = new Material();
 
     for (Node_Iterator it = node->getChildren().begin();
@@ -236,7 +270,7 @@ refptr<Shape> Scene::processBox(refptr<Node> node)
         {
             size = (*it)->getVector();
         }
-        else if ( typeid(**it) == typeid(MaterialNode) )
+        else if ( (*it)->isMaterial() )
         {
             material = processMaterial(*it);
         }
@@ -273,7 +307,7 @@ refptr<Shape> Scene::processCyl(refptr<Node> node)
             radius2 = v[1];
             height = v[2];
         }
-        else if ( typeid(**it) == typeid(MaterialNode) )
+        else if ( (*it)->isMaterial() )
         {
             material = processMaterial(*it);
         }
@@ -340,7 +374,7 @@ refptr<Shape> Scene::processPlane(refptr<Node> node)
             normal = *(*it)->getVector();
             dist = (*it)->getNumber();
         }
-        else if ( typeid(**it) == typeid(MaterialNode) )
+        else if ( (*it)->isMaterial() )
         {
             material = processMaterial(*it);
         }
@@ -375,7 +409,7 @@ refptr<Shape> Scene::processSphere(refptr<Node> node)
         {
             radius = (*it)->getNumber();
         }
-        else if ( typeid(**it) == typeid(MaterialNode) )
+        else if ( (*it)->isMaterial() )
         {
             material = processMaterial(*it);
         }
@@ -415,7 +449,7 @@ refptr<Shape> Scene::processBool(refptr<Node> node)
             }
             shapes_seen++;
         }
-        else if ( typeid(**it) == typeid(MaterialNode) )
+        else if ( (*it)->isMaterial() )
         {
             material = processMaterial(*it);
         }
diff --git a/main/Scene.h b/main/Scene.h
index a689273..8630109 100644
--- a/main/Scene.h
+++ b/main/Scene.h
@@ -70,6 +70,7 @@ class Scene
         void processCamera(refptr<Node> node);
         void processOptions(refptr<Node> node);
         void processTransformBlock(refptr<Node> node);
+        void processMaterialDefinition(refptr<Node> node);
 
         /* rendering parameters */
         int m_width;
@@ -89,6 +90,7 @@ class Scene
         int m_multisample_level_squared;
         double m_sample_span;
         double m_half_sample_span;
+        std::map< std::string, refptr<Material> > m_materials;
 
         /* framebuffer */
         unsigned char * m_data;
diff --git a/parser/nodes.h b/parser/nodes.h
index f3a4767..12b9ea6 100644
--- a/parser/nodes.h
+++ b/parser/nodes.h
@@ -22,6 +22,7 @@ class Node
             return refptr<Vector>(NULL);
         }
         virtual bool isShape() { return false; }
+        virtual bool isMaterial() { return false; }
         virtual std::string getString() { return ""; }
 
     protected:
@@ -135,6 +136,8 @@ class LookAtNode : public VectorNode
 
 class MaterialNode : public Node
 {
+    public:
+        bool isMaterial() { return true; }
 };
 
 class MaterialDefinitionNode : public IdentifierNode
@@ -147,6 +150,7 @@ class MaterialRefNode : public IdentifierNode
 {
     public:
         MaterialRefNode(const std::string & str) : IdentifierNode(str) {}
+        bool isMaterial() { return true; }
 };
 
 class MultisampleNode : public IntegerNode