diff --git a/engine/src/core/com/jme3/material/Material.java b/engine/src/core/com/jme3/material/Material.java
index b9830d9f4..73c928e96 100644
--- a/engine/src/core/com/jme3/material/Material.java
+++ b/engine/src/core/com/jme3/material/Material.java
@@ -794,7 +794,11 @@ public class Material implements CloneableSmartAsset, Cloneable, Savable {
                 case Directional:
                     DirectionalLight dl = (DirectionalLight) l;
                     Vector3f dir = dl.getDirection();
-
+                    //FIXME : there is an inconstencie here due to backward 
+                    //compatibility of the lighting shader.
+                    //The directional light direction is passed in the 
+                    //LightPosition uniform. The lightinf shader needs to be 
+                    //reworked though in order to fix this.
                     tmpLightPosition.set(dir.getX(), dir.getY(), dir.getZ(), -1);
                     lightPos.setValue(VarType.Vector4, tmpLightPosition);
                     tmpLightDirection.set(0, 0, 0, 0);
diff --git a/engine/src/core/com/jme3/shader/UniformBinding.java b/engine/src/core/com/jme3/shader/UniformBinding.java
index 28fd0c405..3ac5cc0e0 100644
--- a/engine/src/core/com/jme3/shader/UniformBinding.java
+++ b/engine/src/core/com/jme3/shader/UniformBinding.java
@@ -171,7 +171,31 @@ public enum UniformBinding {
      * Frames per second.
      * Type: float
      */
-    FrameRate("float");
+    FrameRate("float"),
+    
+    /**
+     * The light position when rendering in multi pass mode
+     * Type: vec4
+     */
+    LightDirection("vec4"),
+    
+    /**
+     * The light direction when rendering in multi pass mode
+     * Type: vec4
+     */
+    LightPosition("vec4"),
+    
+    /**
+     * Ambient light color
+     * Type: vec4
+     */
+    AmbientLightColor("vec4"),
+    
+    /**
+     * The light color when rendering in multi pass mode
+     * Type: vec4
+     */
+    LightColor("vec4");
     
     String glslType;