Modify Shape

offtopic: i had created new account when i thought i forgot the login name but then I found it so please dont let nick names confuse you

Maili,
Please explain in more details what you intend to achieve. If let's say you have a standalone vertical edge from vertex v1 (0,0,0) to v2 (0,0,1) lying on a 3D line and want the edge to become horizontal (from v1 to v2'(1,0,0)) then you can just use BRepBuilderAPI_Transform. No ReShape is necessary.

But if you have a box of side size 1 and want to move one of its vertex (say (0,0,0)) to some other point (say (-1,-1,-1)) and expect all the edges to connect it, this is wrong expectation. You have to do math on your own. This is also possible but is totally different concept.

Roman
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Have you tried like this?

- Use BRepBuilderAPI_Transform to get newVertex from oldVertex
- Use BRepTools_ReShape :: Replace ( oldVertex, newVertex )
- Use BRepTools_ReShape :: Apply ( oldCompund ) to get newCompound

I suffered a lot trying to get that kind of replacements right. It took me some months, actually. You've put yourself into a task which is not easy for an OCC noob, and I can tell. I can also tell it's doable, just not the easiest way to get started with OCC.

Hi Maili,

below you will find a code sample reshaping a vertex provided that it is a single one or it belongs to a line.

I must say I was kind of "inspired" with Paul's fight with reshaping last year and so decided to try myself ;)

However, if you want to reshape faces (or even more complex curves) you will have to extend the code.

///
/// Sets the coordinates of the vertex.
///
/// The array containing the coordinates of the vertex.
void VertexProperty::Coordinates::set(array ^ value)
{
int i = 0;
TopoDS_Vertex vertex;
vertex = TopoDS::Vertex(theShapeMap->FindKey(objectIdentifier));

//=================================acquire entity
gp_Pnt point = BRep_Tool::Pnt(vertex);

if( (value[0] != point.X()) || (value[1] != point.Y()) || (value[2] != point.Z()))
{
int nbAssemblies = doc->GetNbAssemblies();
if(nbAssemblies > 0 )
{
GeoAssembly *geoAssembly = doc->GetOCCDoc()->GetAssembly(nbAssemblies);
if(geoAssembly != NULL)
{
GeoEntity *gE = geoAssembly->GetEntityWithIdentifier(entityIdentifier);

if(gE != NULL)
{
if( ((shell::Enums::GeoEntityType)gE->GetGeoEntityType()) ==
shell::Enums::GeoEntityType::Topological)
{
CGeoEntityArray *geoEntities = new CGeoEntityArray;

//================== Check whether the vertex is shared by another entities
// if so and the other entities are linear edges
// add them to the 'update map of shapes'
ArrayList ^idList = gcnew ArrayList();
doc->GetDocumentEntities(idList);

for(i = 0; i < idList->Count; i++)
{
GeoEntity *entity = geoAssembly->GetEntityWithIdentifier(System::Int32::Parse(idList[i]->ToString()));

if( ((shell::Enums::GeoEntityType)entity->GetGeoEntityType()) ==
shell::Enums::GeoEntityType::Topological)
{
bool vertexFound = false;

for(TopExp_Explorer Ex(entity->GetTopoShape(), TopAbs_VERTEX); Ex.More(); Ex.Next())
{
if(TopoDS::Vertex(Ex.Current()).IsEqual(vertex))
{
vertexFound = true;
break;
}
}

if(vertexFound == true)
{
if(CheckShapeToUpdateVertexOf(entity->GetTopoShape(), vertex, value) == false)
{
if(geoEntities != NULL)
{
while(geoEntities->GetUpperBound() >= 0)
{
//zero-based index
GeoEntity *gE = geoEntities->GetAt(0);
gE = NULL;
geoEntities->RemoveAt(0);
}
delete geoEntities;
geoEntities = NULL;
}
return;
}
else
geoEntities->Add(entity);
}
}
}
//==================

if(geoEntities->GetCount() > 0)
{
BRep_Builder builder;
builder.UpdateVertex(vertex, gp_Pnt(value[0], value[1], value[2]), Precision::Confusion());

for(i = 0; i < geoEntities->GetCount(); i++)
{
if(geoEntities->ElementAt(i)->GetTopoShape().ShapeType() == TopAbs_VERTEX)
{
UpdateVertex(geoEntities->ElementAt(i), vertex);
}
else
{
UpdateEdge(geoEntities->ElementAt(i), vertex);
}
}
}

if(geoEntities != NULL)
{
while(geoEntities->GetUpperBound() >= 0)
{
//zero-based index
GeoEntity *gE = geoEntities->GetAt(0);
gE = NULL;
geoEntities->RemoveAt(0);
}
delete geoEntities;
geoEntities = NULL;
}
}
}
else
{
TraceError(" VertexProperty Error. GeoEntity pointer NULL.");
}
}
else
{
TraceError(" VertexProperty Error. GeoAssembly pointer NULL.");
}
}
else
{
TraceError(" VertexProperty Error. No assemblies.");
}
}
}

///
/// Updates a single-vertex-shape.
///
/// The GeoEntity with the vertex to change.
/// The changed vertex.
void VertexProperty::UpdateVertex(GeoEntity * gE, TopoDS_Vertex & vertex)
{
Handle(ShapeBuild_ReShape) reshaper = new ShapeBuild_ReShape;
TopoDS_Vertex vertexToChange = TopoDS::Vertex(gE->GetTopoShape());

reshaper->Replace(vertexToChange, vertex);
gE->GetTopoShape() = reshaper->Apply(gE->GetTopoShape());
reshaper->Clear();

gE->SetAISShapeChanged(true);
gE->UpdateAISShape();
view->GetOCCViewer()->UpdateView();
}

///
/// Updates all linear edges of the given shape
/// containing the vertex whose coordinates change.
///
/// The GeoEntity with the edge(s) to change.
/// The changed vertex.
void VertexProperty::UpdateEdge(GeoEntity * gE, TopoDS_Vertex & vertex)
{
TopoDS_Vertex first, last, unchangedVertex;
TopTools_IndexedMapOfShape edgesMap;
TopExp::MapShapes(gE->GetTopoShape(), TopAbs_EDGE, edgesMap);
Handle(ShapeBuild_ReShape) reshaper = new ShapeBuild_ReShape;
int edgesUpdates = 0;

for(int j = 1; j <= edgesMap.Extent(); j++)
{
TopExp::Vertices( TopoDS::Edge(edgesMap(j)), first, last);

if(first.IsEqual(vertex) || last.IsEqual(vertex))
{
if(first.IsEqual(vertex))
{
unchangedVertex = last;
reshaper->Replace(edgesMap(j), BRepBuilderAPI_MakeEdge(vertex, unchangedVertex));
}
else
{
unchangedVertex = first;
reshaper->Replace(edgesMap(j), BRepBuilderAPI_MakeEdge(unchangedVertex, vertex));
}

edgesUpdates++;
}
}

TraceDebugFormattedStr(" VertexProperty. Updated edges: ", "%i", ".", edgesUpdates);
if(edgesUpdates > 0)
{
gE->GetTopoShape() = reshaper->Apply(gE->GetTopoShape());
reshaper->Clear();

ShapeFix_Shape fixer(gE->GetTopoShape());
fixer.Perform();
gE->GetTopoShape() = fixer.Shape();

gE->SetAISShapeChanged(true);
gE->UpdateAISShape();
view->GetOCCViewer()->UpdateView();
}

edgesMap.Clear();
}

///
/// Checks if an update/change of the given vertex is possible.
///
/// The shape with the vertex to change.
/// The changed vertex.
/// The new coordinates of the vertex.
/// If the shape is a 'VERTEX' or a linear 'EDGE'
/// and the change of the vertex coordinates does not
/// lead to reducing the the edge into a point
/// the method returns true. Otherwise false.
bool VertexProperty::CheckShapeToUpdateVertexOf(TopoDS_Shape & shape, TopoDS_Vertex & vertex, array ^ value)
{
if(shape.ShapeType() == TopAbs_VERTEX)
{
return true;
}

if(shape.ShapeType() != TopAbs_EDGE)
{
TraceWarning(" VertexProperty Warning. Only edges can be modified.");
return false;
}
Standard_Real f, l; //first and last parameter
Handle_Geom_Curve curve = BRep_Tool::Curve(TopoDS::Edge(shape), f, l);
if(GeomAdaptor_Curve(curve).GetType() != GeomAbs_Line)
{
TraceWarning(" VertexProperty Warning. Only linear edges can be modified.");
return false;
}

TopoDS_Vertex first, last, unchangedVertex;
TopTools_IndexedMapOfShape edgesMap;
TopExp::MapShapes(shape, TopAbs_EDGE, edgesMap);

gp_Pnt changedPoint = BRep_Tool::Pnt(vertex);

for(int j = 1; j <= edgesMap.Extent(); j++)
{
TopExp::Vertices( TopoDS::Edge(edgesMap(j)), first, last);

if(first.IsEqual(vertex) || last.IsEqual(vertex))
{
if(first.IsEqual(vertex))
{
unchangedVertex = last;
}
else
{
unchangedVertex = first;
}

gp_Pnt unchangedPoint = BRep_Tool::Pnt(unchangedVertex);

if(unchangedPoint.IsEqual(gp_Pnt(value[0], value[1], value[2]), Precision::Confusion()) == Standard_True)
{
TraceWarning(" VertexProperty Warning. Vertices would be the same.");
return false;
}
}
}

return true;
}