Feature Request: 3d Seed Point Viz

[bzenger]

Description

Feature Request: Display and modify seed points within the 3d viewer. I would like to be able to visualize the seed points placed using any tool (but definitely the implicit model tool) on the rendered isosurface. I would then like to be able to delete the points from the render window. Ideally this could be expanded to moving the points in the 3d renderer but I don't think that is necessary to start with.