can we show the orig.ident in separate windows by using Seurat
The DimPlot() function of the new version of Seurat, Seurat v3 has a split_by argument, which splits the plot based on the levels of the variable provided. You basically need to provide a column from the @metadata slot.

If you are using Seurat v2, you can have the DimPlot() function return the ggplot object created and then use facet_wratp() or facet_grid() to generate facets based on your variable of interest.