Visualizing heatmaps in the surface of 3D models


I'm trying to visualize heatmaps in the surface of 3D models in OpenCascade 7.3.0. Unfortunately, I've been unable to properly color a model since AIS_TexturedShape, aparently, only allows to give a texture to each face and I will have a map of the whole model.

I have been also testing with MeshVS_Mesh but the result is not as I expected. Here is the piece of code I have used to color the mesh:

void MainWindow::makeMesh(Standard_CString file_model_path)
    Handle_Poly_Triangulation aPolyTriang = RWStl::ReadFile ("Cylinder.stl");
    Handle_XSDRAWSTLVRML_DataSource aDataSource = new XSDRAWSTLVRML_DataSource (aPolyTriang);

    // create mesh
    Handle_MeshVS_Mesh aMesh = new MeshVS_Mesh();
    aMesh->SetDataSource  (aDataSource);

    Handle_MeshVS_NodalColorPrsBuilder aBuilder = new MeshVS_NodalColorPrsBuilder(aMesh,MeshVS_DMF_NodalColorDataPrs | MeshVS_DMF_OCCMask);
    aMesh->AddBuilder (aBuilder, Standard_True);

    // prepare color map
    Aspect_SequenceOfColor  aColorMap;
                            aColorMap.Append  (Quantity_NOC_RED);
                            aColorMap.Append  (Quantity_NOC_BLUE1);
                            aColorMap.Append  (Quantity_NOC_VIOLET);

    TColStd_DataMapOfIntegerReal  aScaleMap;
    int anId=0; double aValue=0;

    // iterating through the nodes
    const TColgp_Array1OfPnt& mNodes=aPolyTriang->Nodes();
    for(auto point:mNodes)

       //Giving one color to nodes with high Z and another to the low ones
       if (aPolyTriang->Node(anId).Z()>100)

       aScaleMap.Bind  (anId, aValue);

    // pass color map and color scale values to the builder
    aBuilder->SetColorMap  (aColorMap);

    aMesh->AddBuilder  (aBuilder, Standard_True);

    mContext->Activate(aMesh); //Activating the AIS_interactiveContext

    mContext->Display(aMesh, 3, TopAbs_SHAPE, true); //Displaying the mesh


As you can see in the attached image, I get the colored mesh but i think the lines of the triangulation are also represented in yellow and i can't get rid of them.

Does anyone know who to load a shape and color its surface with a color map? As I say, I'm open to use the raw data of the map and insert it in a mesh and to load the map with an image file and apply it to the whole shape.


Thanks in advance!



Kirill Gavrilov's picture

MeshVS defines its own set of presentation parameters via MeshVS_Drawer class and MeshVS_DrawerAttribute enumeration.
MeshVS_DA_ShowEdges is enabled by default, but can be disabled.

Alvaro Fernandez's picture

Yes, it works fine with this new line.

aMesh->GetDrawer()->SetBoolean(MeshVS_DA_ShowEdges, false);

Thank you very much!