[plot3d] Display issue with silx view
On macOS with python3.5 and Qt 5.9 with six view, the 3D view has the previous widget in the background. This is visible with transparent isosurface
diff --git a/silx/gui/plot/backends/BackendOpenGL.py b/silx/gui/plot/backends/BackendOpenGL.py
index f482d3e52..31db02cd3 100644
--- a/silx/gui/plot/backends/BackendOpenGL.py
+++ b/silx/gui/plot/backends/BackendOpenGL.py
@@ -300,6 +300,7 @@ _texFragShd = """
 
     void main(void) {
         gl_FragColor = texture2D(tex, coords);
+        gl_FragColor.a = 1.0;
     }
     """
 
@@ -437,7 +438,7 @@ class BackendOpenGL(BackendBase.BackendBase, glu.OpenGLWidget):
 
     @staticmethod
     def _setBlendFuncGL():
-        # glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA)
+        # gl.glBlendFunc(gl.GL_SRC_ALPHA, gl.GL_ONE_MINUS_SRC_ALPHA)
         gl.glBlendFuncSeparate(gl.GL_SRC_ALPHA,
                                gl.GL_ONE_MINUS_SRC_ALPHA,
                                gl.GL_ONE,
diff --git a/silx/gui/plot3d/scene/window.py b/silx/gui/plot3d/scene/window.py
index 64bd39c34..3c63c7a2d 100644
--- a/silx/gui/plot3d/scene/window.py
+++ b/silx/gui/plot3d/scene/window.py
@@ -244,6 +244,7 @@ class Window(event.Notifier):
 
         void main(void) {
             gl_FragColor = texture2D(texture, textureCoord);
+            gl_FragColor.a = 1.0;
         }
         """)
 
['silx/gui/plot/backends/BackendOpenGL.py', 'silx/gui/plot3d/scene/window.py']