diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..2061eca
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,6 @@
+# Byte-compiled
+*.pyc
+
+# IDE setting
+.idea/
+
diff --git a/README.txt b/README.md
similarity index 76%
rename from README.txt
rename to README.md
index 95fe88b..6442bec 100644
--- a/README.txt
+++ b/README.md
@@ -1,18 +1,23 @@
-=============================================
 PROJECT
-Pycado alpha version
-
 =============================================
+### Pycado alpha version
+
+| **Build in Windows**                              | **Build in macOS**                               |
+| :----:                                            | :----:                                           |
+| <img src="./pycado/data/cnc_components.jpg" width="480" alt="demo_Windows"/> | <img src="./pycado/data/cnc_component_mac.png" width="480" alt="demo_Mac"/> |
+
 DESCRIPTION
+=============================================
 Pycado is an object oriented 3D CAD scripting language based on pythonocc with a graphical interactive editor
 
-=============================================
 AUTHORS
+=============================================
 Julien Blanchard - julienbld --- yahoo --- fr
+
 Charles Clément - caratorn --- gmail --- com
 
-=============================================
 HOMEPAGE
+=============================================
 https://github.com/julienbld/pycado
 
 
@@ -48,9 +53,8 @@ dependency tree.
 
 2 - INSTALLATION
 ================
-Pycado is based on pythonocc, so the first step is to install pythonocc, which
-depends on the OpenCASCADE library (http://www.opencascade.org/), swig 
-(http://www.swig.org/), QScintilla(http://www.riverbankcomputing.co.uk/software/qscintilla).
+Pycado is based on pythonocc, so the first step is to install [pythonocc](https://github.com/tpaviot/pythonocc-core), which
+depends on the [OpenCASCADE library](http://www.opencascade.org/), [swig](http://www.swig.org/), [QScintilla](http://www.riverbankcomputing.co.uk/software/qscintilla).
 
 
 
diff --git a/pycado/data/cnc_component_mac.png b/pycado/data/cnc_component_mac.png
new file mode 100644
index 0000000..8b9fcb3
Binary files /dev/null and b/pycado/data/cnc_component_mac.png differ
diff --git a/pycado/data/cnc_components.jpg b/pycado/data/cnc_components.jpg
new file mode 100644
index 0000000..6c8a194
Binary files /dev/null and b/pycado/data/cnc_components.jpg differ
diff --git a/pycado/nspace.py b/pycado/nspace.py
index 9d7d552..1b9d77c 100644
--- a/pycado/nspace.py
+++ b/pycado/nspace.py
@@ -2,7 +2,7 @@
 import OCC.Quantity
 from OCC.Graphic3d import *
 from OCC import TopExp, BRepPrimAPI, TopAbs, TopoDS, BRep
-from OCC.Utils.Topology import Topo
+from OCCUtils.Topology import Topo
 from OCC.BRepAlgo import *
 from OCC.TopoDS import TopoDS_Compound
 
diff --git a/pycado/pycado.py b/pycado/pycado.py
index 4645a00..7ef4904 100644
--- a/pycado/pycado.py
+++ b/pycado/pycado.py
@@ -236,8 +236,10 @@ def main(argv=sys.argv):
   # INIT DISPLAY   
   gui.canva.InitDriver()
   #gui.canva._display.SetBackgroundImage(nspace.config["background"])
-  gui.canva._display.SetBackgroundImage(get_abs_filename())
-  #gui.canva._display.GetViewer().GetObject().SetDefaultBackgroundColor(OCC.Quantity.Quantity_NOC_YELLOW)
+  #gui.canva._display.SetBackgroundImage(get_abs_filename())
+  gui.canva._display.GetView().GetObject().SetBgGradientColors(OCC.Quantity.Quantity_NOC_NAVYBLUE,
+                                                               OCC.Quantity.Quantity_NOC_SNOW,
+                                                               OCC.Aspect.Aspect_GFM_VER)
   gui.canva._display.View_Iso()
 
     
diff --git a/pycado/pycado_obj.py b/pycado/pycado_obj.py
index ac3edb2..7f88c6e 100644
--- a/pycado/pycado_obj.py
+++ b/pycado/pycado_obj.py
@@ -269,7 +269,7 @@ def build(self):
         self.data = BRepAlgo_Cut(args[1].topology, args[2].topology)
         ex = TopExp_Explorer()
         ex.Init(self.data.Shape(), TopAbs_FACE)
-        self.topology = TopoDS().Face(ex.Current())
+        self.topology = topods_Face(ex.Current())
     else:
       self.value = args
       self.data = BRepBuilderAPI_MakeWire()
diff --git a/pycado/qt_display.py b/pycado/qt_display.py
index 71c75a9..8d92166 100644
--- a/pycado/qt_display.py
+++ b/pycado/qt_display.py
@@ -116,7 +116,7 @@ def InitDriver(self):
             raise "Please set the CSF_GraphicShr environment variable."
         self._display = OCCViewer.Viewer3d(self.GetHandle())
         self._display.Create()
-        self._display.DisplayTriedron()
+        self._display.display_trihedron()
         self._display.SetModeShaded()
         self._inited = True
         # dict mapping keys to functions
@@ -131,8 +131,7 @@ def set_shade_mode():
                          ord('S'): set_shade_mode,
                          ord('A'): self._display.EnableAntiAliasing,
                          ord('B'): self._display.DisableAntiAliasing,
-                         ord('Q'): self._display.SetModeQuickHLR,
-                         ord('E'): self._display.SetModeExactHLR,
+                         ord('H'): self._display.SetModeHLR,
                          ord('F'): self._display.FitAll,
                          #ord('F'): self._display.ExportToImage("essai.BMP"),
                          #ord('F'): self._display.SetBackgroundImage("carrelage1.gif"),