How to create the outer nodes effect in Blender Cycles, including the lines? I know this is achieved using a particle system, but don't know how.
Also can anybody suggest any plugins for blender that does the same?
I would use Sverchok (A Blender node system for Geometry)
Click on the image to view full size.
How it works is you feed Sverchok a base mesh, in this case the blue Icosphere with some distorted noise displacement. This mesh is used to generate a second set of vertices positioned some distance away in the direction of the vertex normal. The vertex normal is defined by the average face normal of all faces which are connected to a vertex.
This new set of vertices has the same vertex index order, this means we can reuse the edge list (list of vertex indices which makes up each edge) and create tubing from the resulting edges.
The new set of vertices is also used to place duplicated instances of the node sphere (in this case a NURBS SurfaceSphere)
_0appended. This node outputs the new (offset) vertices.
Sigma_0 : The tubes, Curve Objects, generated by SvCurveViewer Sigma. These tubes are built from new vertices and old edge list.
SurfSphere: In properties set the parent to Alpha_0, this will then duplicate the SurfSphere at every vertex of Alpha_0's mesh.
You'll notice as soon as you parent an object, that the child becomes part of the parent item. The outliner shows it like this:
If you're not married to the particle system idea, you could model this with a a few meshes.
1) Make the mesh (I did this with an icosphere and some proportional editing):
You can make the duplicates now with Shift+D in object mode.
Add a sphere (I did a low-poly icosphere with a subsurf modifier and smooth shading).
Make your main mesh a parent of the new sphere (select the sphere, then shift+select the main mesh, then Ctrl+P parent to object).
Set the main object to duplivert:
2) On one of your duplicates, add a wireframe modifier:
3) For your final duplicate, simply scale it down a bit to fit inside the others.