In the default state, the volume date is displayed in the box [-1, -1, -1] - [1, 1, 1], regardless of the boxel size number of the data.
If the volume box is not cubic one, change the values X,Y,Z-range.
If the each boxel is cubic, "Auto Rescale" in Edit(E) menu would change the values according to the size of the data.
Rot(zxyz) rotates the volume box along the each axis, and Alpha determine the transparency of the entire volume.
Changing the box size rescale the entire data.
If you want to make a movie with moving cross section, use "Clipping" filter.