How would you approach modeling soft surface (for example character face) (Houdini Amarok)

[ISUther]

I got now image planes set and i know how to set material on to it and lower visibility of the object so i can see image thro that object, but what tool would you recommend to start with in order to create head shape?
1.) Create a geo node
2.) Dive inside
3.) Delete what ever is inside to get fresh start
4.) Assign material
5.) Change visibility so i can see background image to model
6.) Create Eyes form sphere for example
But what about main element "head"
Place flat grid front to it or make it some how 4 sections and create front topology like that? 
What tool would you recommend to use?

I am sorry for having so many questions. 
I am beginner in this.

Edited March 6, 2017 by ISUther

[6ril]

Have you watched some head modeling tutorials ?

there's different approach to this.

Also, there's one important thing that might change the modeling method : will that head be animated or not. If not, you can go crazy, but if you intend to animate it, then you need to model it with special care of the topology (edgeloop at key places) in order to support the deformations nicely.

[jim c]

Couple of things you can do.

Look up "Box Modeling" and you'll see how a simple box can be divided up and manipulated into more complex forms, like a head. To start with that drop down a Box SOP. You can then go to the Polygon shelf and use the cut lines or edges (I can't recall exactly what it's called), but it lets you interactively place new edge loops in your geo. That lets you add more detail to the mesh, where you want it and form there you can use the edit sop (typically in Point mode) to manipulate (transform/rotate/scale) points. If you just model one side, along the x-axis for example, then you can delete the other side, and use the Mirror SOP to mirror over your geo.

You can use a series of metaballs all merged together and fed into a VDB Volume and then converted into a mesh (Convert VDB SOP) as another way to set up some core forms, and then use the retopo tools to give proper edge loops.

There's the NURBs tools as well, but those are probably more hassle then they are worth.