Wed, 04/14/2004 - 12:17
Forums:
Hi everyone!
I am new to OpenCascade and I am trying to do the following:
-import a step file using the ImportExport Example
-get all shapes from the interactive context
-apply a layer on top of the imported object by using boolean
operations.
I can use
myAISContext->DisplayedObjects(aList);
to get a list of all objects in the context. Now how can I access the single shapes contained in this list? Can anybody give a short example for accessing two boxes from the InteractiveContext and then being merged by boolean operations?
Regards,
Udo
Wed, 04/14/2004 - 15:07
You perform traversal of Open Cascade List objects with list iterators.
To traverse an AIS_ListOfInteractive object, use an AIS_ListIteratorOfListOfInteractive object :
myAISContext->DisplayedObjects(aList);
AIS_ListIteratorOfListOfInteractive it (aList);
//iterate on list:
while (it.More ())
{
//do something with the current item : it.Value ()
it.Next ();
}
Wed, 04/14/2004 - 16:16
Hi Hugues,
thanks for your reply. I konow about the iterator, but how can I access the shapes of the returned objects?
it.Value() returns a Handle_AIS_InteractiveObject. Can I convert this somehow to a TopoDS_Shape?
Wed, 04/14/2004 - 19:18
Sorry for my dummy answer, here is what you can do to access the underlying shape :
Normally, your AIS_InteractiveObject instances are AIS_Shape objects.
So you should cast them :
//"it" is an iterator on a list of InteractiveObject instances.
Handle_AIS_InteractiveObject current_ais_item = it.Value ();
assert (current_ais_item->IsKind (STANDARD_TYPE (AIS_Shape));//instance_of_ais_shape
Handle_AIS_Shape current_ais_shape = Handle_AIS_Shape::DownCast (current_ais_item);
assert (not current_ais_shape.IsNull ());//not_null
const TopoDS_Shape& current_topo_shape = current_ais_shape->Shape ();
Try this code, I have not test it, but this is a way to get what you need.
Wed, 04/14/2004 - 19:56
Thanks, that was exactly what I needed´to get a good start on solving my problem!