Convert visual layers to scene nodes.

src/visual_elements/CMakeLists.txt

@@ -1,9 +1,14 @@
 list(APPEND visual_elements_LIB_INCLUDES
     GeometryNode.cpp
     RectangleNode.cpp
+    MaterialNode.cpp
     TextNode.cpp
-    VisualLayer.cpp
     Scene.cpp
+    SceneModel.cpp
+    SceneItem.cpp
+    SceneText.cpp
+    Transform.cpp
+    Texture.cpp
 )
 
 add_library(visual_elements SHARED ${visual_elements_LIB_INCLUDES})