model.result(<pgtag>).feature(<ftag>).create(<atag>,"Transparency") adds transparency named
<atag> as an attribute to an isosurface, surface, volume, contour, slice, multislice, mesh, line, pellets, streamline, streamline multislice, streamline surface, table annotation, or whirl 3D plot named
<ftag> or to a contour, function, histogram, line, matrix histogram, optical aberration, surface, table histogram, or table surface 2D plot named
<ftag> and using a height expression attribute.