A mimimal example Cascade & 3D viewer (V3d_Viewer)

Data in class or global data:

Handle_Graphic3d_WNTGraphicDevice myGraphicDevice;
Handle_V3d_Viewer myViewer;
Handle_AIS_InteractiveContext myAISContext;
Handle_V3d_View myView;
Handle_WNT_WClass myWClass;
Handle(WNT_Window) aWNTWindow;

Code of 3D view initialization:

myGraphicDevice = new Graphic3d_WNTGraphicDevice();

Handle(Graphic3d_WNTGraphicDevice) theGraphicDevice = myGraphicDevice;
theGraphicDevice = myGraphicDevice;
//Handle(WNT_Window) aWNTWindow = new WNT_Window(theGraphicDevice,parent_window);
try {
myWClass= new WNT_WClass((char*)L"some_class_fdfdddd",NULL,CS_HREDRAW|CS_VREDRAW);
} catch (WNT_ClassDefinitionError &err) {
int errcode=GetLastError();
int x=0;
}
WNT_Window * t = new WNT_Window(theGraphicDevice,"some_win_mmmmddddd",myWClass,WS_VISIBLE ,1,1,400,400,Quantity_NOC_MATRAGRAY,NULL);
//WNT_Window * t = new WNT_Window(theGraphicDevice,"some_win_mmmmddddd",myWClass,WS_CHILD | WS_VISIBLE | WS_TABSTOP,1,1,400,400,Quantity_NOC_MATRAGRAY,parent_window);
aWNTWindow = t;
myViewer = new V3d_Viewer(theGraphicDevice,(short *) "Visu3D");
myViewer->SetDefaultLights();
myViewer->SetLightOn();
myView = myViewer->CreateView();
myView->SetWindow(aWNTWindow);
if (!aWNTWindow->IsMapped()){

aWNTWindow->Map();
}
myAISContext =new AIS_InteractiveContext(myViewer);

Handle(V3d_Viewer) aViewer = myViewer;
Handle(AIS_InteractiveContext) aContext;
aContext = new AIS_InteractiveContext(aViewer);

BRepPrimAPI_MakeSphere S(gp_Pnt(0,300,0), 100.);
Handle(AIS_Shape) aisthing=new AIS_Shape(S.Shape());
aContext->SetDisplayMode(aisthing,AIS_Shaded);
aContext->Display(aisthing);
aContext->DisplayAll();

thanks for Travers Biddle http://www.opencascade.org/org/forum/thread_23530/?forum=3

Be sure to call

aContext->SetDisplayMode(aisthing,AIS_Shaded);
aContext->Display(aisthing);

everytime when you modify the shape.

Be sure to call

aContext->Display(aisthing);

everytime when WM_PAINT processed