chapter 5

Make both subdivision and spring attachment work through Face. TODO: …

…what remains is inner ball for 3D and other forces between them, and then code clean up and docs.

The best out come to date with the 2-layer 3D ball with all types of …

…springs working. Be careful when tweaking params in global.h.

Make subdivision work (was missing new Particle() for pa, pb, pc. TOD…

…O: proper spring updates.

will work on 3d. nearest point, normal for faces are working

Basically, 1D and 2D were debugged with Euler. Begin adapting 3D and …

…closest point for dragging.

Commit somewhat working stuff before code clean up.