I would like to display a 3D lattice DAG, where every vertex has associated integer (x,y,z) coordinates, and the edges are the edges of the corresponding cubic lattice. I can build the graph with vtkMutableDirectedGraph and vtkTree, but I can’t figure out how to assign the coordinates and which mapper to use (I want vertices as spheres and edges as tubes or arrows).
There’s vtkGraph.SetPoints, but are those associated with the vertices? There’s vertex data which I could use to store the coordinates, but how can I set the data as I add each vertex (and not as a whole array for all vertices at one shot), and how I can use this in a mapper?
For instance, using Python, I can create this simple vtkTree:
graph = vtk.vtkMutableDirectedGraph()
v0 = graph.AddVertex()
v1a = graph.AddVertex()
v1b = graph.AddVertex()
v1c = graph.AddVertex()
graph.AddEdge(v0, v1a)
graph.AddEdge(v0, v1b)
graph.AddEdge(v0, v1c)
coord = vtk.vtkIntArray()
coord.SetName('coord')
coord.SetNumberOfComponents(3)
coord.InsertNextTuple([0,0,0])
coord.InsertNextTuple([1,0,0])
coord.InsertNextTuple([0,1,0])
coord.InsertNextTuple([0,0,1])
graph.GetVertexData().AddArray(coord)
tree = vtk.vtkTree()
tree.CheckedShallowCopy(graph)
How can I now display it, as I said, with spheres and tubes? (And ideally adding the coordinates in the AddVertex calls)