Random extrusions to make spikes and rigging those spikes?

[oldiesgoodies]

Hi

I have started learning Houdini recently. I am enjoying it a lot. I have been a 3d artist for a long time and I have used a lot of applications in the past. I wonder why I have not started learning Houdini before.

At the moment I am trying to make some basic test learning stuff for myself and trying to achieve particular model and automated rigging process.

What I need is basically

-A sphere with random selections (Lets say that the sphere has 300 quads and I want to select 15 random primitives)

-Extrude those selections couple times make some random spikes

-Create a simple rigging system so that all those randomly extruded spikes would have some basic rigging via bones(one bone hierarchy per spike) or any other means that can provide similar functionality

So far I managed to learn how to randomly select couple primitive via group expression via rand expression.

I just need basic train of thought and possible methods to explore.

thanks