Custom labels on VTKHexahedrons


I’m new to VTK. I’m writing a QTWidget which displays thousands of VTKHexahedrons stacked on each other using VTKUnstructuredGrid. I need to label the “visible” faces of each VTKHexahedron with a custom label.

I looked into VTKTextProperty but it requires a VTKTextActor for each Property and that does not scale well. The other option I looked at was using VTKLabeledDataMapper using cell attributes but I need custom labels to display not cell-id’s.

Is there a way to do this ? Any sample code would be really helpful. Any suggestions/ideas will be greatly appreciated !