Various macros for positioning objects.

In the following examples, `S`

is a sphere primitive with
radius 0.5, and `C`

is a cube of length 0.4.

`N_roots(N, R, Ob)`

:

`Ob`

at each `N`

th root of unity in the xz-plane,
at distance `R`

from 0.
`N_roots_SR(N, R, Ob, Sc, Rt)`

:

```
N_roots(N, R,
Ob)
```

, with the `K`

th copy of `Ob`

scaled by
`1+Sc*K`

and rotated by `Rt*K`

for each 0,...,`K`

.
`Row(Ob, Start, N, Space)`

:

`N`

copies of object `Ob`

in a row, starting at point `Start`

and spaced apart by vector
`Space`

.
`Row_SR(Ob, Start, N, Space, R, S)`

:

```
Row(Ob, Start, N,
Space)
```

but with the `K`

th copy of `Ob`

scaled by
`1+S*K`

and rotated by `R*K`` for each 0,...,``K`

.

```
```