A piece of code using MSAGL with the GDI viewer is able to make an acceptable rendition of a graph with subgraphs, e.g.:

open System.Windows.Controls
open System.Windows.Media
open Microsoft.Msagl.Drawing

type GraphViewer = Microsoft.Msagl.GraphViewerGdi.GViewer

let addNamespaceToGraph (graph: Graph) (ns: string) =
    let rec loop (parentGraph: Subgraph) (path: string list) (names: string list) =
        match names with
        | [] -> ()
        | name :: rest ->
            let path' = name::path
            let subNamespace = String.Join('.', path' |> List.rev)
            let subgraph' =
                match parentGraph.Subgraphs |> Seq.tryFind (fun sg -> sg.Id = subNamespace) with
                | Some sg -> sg
                | None ->
                    let newSubgraph = new Subgraph(subNamespace)
                    newSubgraph.LabelText <- name
                    parentGraph.AddSubgraph(newSubgraph)
                    newSubgraph
            loop subgraph' path' rest
            
    let root = graph.RootSubgraph
    let path = ns.Split('.') |> List.ofArray
    loop root [] path
                
let createGraph () : Graph =
    let graph = new Graph("Namespaces")

    let addNamespace = addNamespaceToGraph graph

    // Add namespaces
    addNamespace "Foo.Bar.Baz"
    addNamespace "Foo.Bar.Qux"
    addNamespace "Foo.Baz"

    // Add an edge between nodes in different subgraphs
    graph.AddEdge("Foo.Bar.Baz", "Foo.Baz") |> ignore

    graph

let showGraph (graph: Graph) =
    let viewer = new GraphViewer()

    viewer.Graph <- graph // Set the graph after layout is performed

    viewer

let graph = createGraph()

showGraph graph |> Dump

Becomes:

However, almost identical code, using the WPF viewer makes an unusable rendition:

open System.Windows.Controls
open System.Windows.Media
open Microsoft.Msagl.Drawing

type GraphViewer = Microsoft.Msagl.WpfGraphControl.GraphViewer

let addNamespaceToGraph (graph: Graph) (ns: string) =
    let rec loop (parentGraph: Subgraph) (path: string list) (names: string list) =
        match names with
        | [] -> ()
        | name :: rest ->
            let path' = name::path
            let subNamespace = String.Join('.', path' |> List.rev)
            let subgraph' =
                match parentGraph.Subgraphs |> Seq.tryFind (fun sg -> sg.Id = subNamespace) with
                | Some sg -> sg
                | None ->
                    let newSubgraph = new Subgraph(subNamespace)
                    newSubgraph.LabelText <- name
                    parentGraph.AddSubgraph(newSubgraph)
                    newSubgraph
            loop subgraph' path' rest
            
    let root = graph.RootSubgraph
    let path = ns.Split('.') |> List.ofArray
    loop root [] path
                
let createGraph () : Graph =
    let graph = new Graph("Namespaces")

    let addNamespace = addNamespaceToGraph graph

    // Add namespaces
    addNamespace "Foo.Bar.Baz"
    addNamespace "Foo.Bar.Qux"
    addNamespace "Foo.Baz"

    // Add an edge between nodes in different subgraphs
    graph.AddEdge("Foo.Bar.Baz", "Foo.Baz") |> ignore

    graph

let showGraph (graph: Graph) =
    let viewer = new GraphViewer()

    let canvas = new Canvas()
    viewer.BindToPanel(canvas)

    viewer.Graph <- graph // Set the graph after layout is performed

    canvas

let graph = createGraph()

showGraph graph |> Dump

Becomes:

What can I do to fix the rendering with the WPF viewer, if anything?