fixed camera displacement issue

also removed some lines that haven't been used in ages
fixed a dodecahedral / tetra-octa conversion error

also, i'm sorry
added casting from camera down the front axis!

it's, as we say, not good, and there are the perennial issues of
unlattice getting the wrong coordinate and the whole thing failing at
certain positions, but it's working and that's currently good enough
tweaked the smoothing formula slightly

short version, material pushes are normalized before being weighed,
which makes the deformation slightly more regular when deforming
vertices with four adjacent cells