I am trying to add the cell picker functionality in my glance app. I tried doing this by extending the ViewProxy.js class. found here \glance\node_modules\@kitware\vtk.js\Proxy\Core\ViewProxy.js. Everything seems to work fine except the sphere do not show when the click event onRightButtonPress gets called. Perhaps I am doing it wrong or extending the wrong class. I have created a gist found here Implement CellPicker in ParaviewGlance