.scn file:
----------
  object tree
  textures
  starfield
  palette

object tree:
------------
one of the below
  -node
  -object
  -light source

node:
-----
  0 number of nodes
    number of nodes * ( objecttree )
    move list

object:
-------
  1 filename.dat
    status list
    move list

light source:
-------------
  2
    move list

move/status list:
----------
  time/sec  movecommand/statuscommand     (time==0 => time=lasttime)
  time/sec  movecommand/statuscommand
  ...
  10000

movecommand:
------------
  -pos  x y z
    position object

  -move dx dy dz
    move object

  -accel ddx ddy ddz
    accelerate object

  -smove deltatime/sec  x y z  dx dy dz
    smooth move:
      move object from current pos/speed to pos x y z / speed dx dy dz

  -angle x y z
    set angle

  -rot dx dy dz
    rotate object

  -aaccel ddx ddy ddz
    angle acceleration


status command:
---------------
  -enable
    makes this object visible

  -disable
    makes this object invisible

  -setcut cutnum   (objects only)
    enables spacecut for this object, will be intersected with all objects
     of the same cutnum
    cutnum==-1 => disable spacecut

  -setspeed speed  (starfield only)
    sets the speed of the stars

  -setmaxcol maxcol (starfield only)
    set the maximum color of the stars


textures:
---------
  number of textures
    number of textures * ( texture )

texture:
--------
one of the below:
  -imagemap
  -plasma
  -sineplasma

imagemap:
---------
  0 filename.tga
    256 color uncompressed cmap

plasma:
-------
  1 xybit xaux yaux cbit roughness seed
      wid=2^(xybit+xaux), hgt=2^(xybit+yaux), col=2^cbit

sineplasma:
-----------
  2 wid hgt col numop numop * (p dp f a w)
     numop rotating sine waves
      sine operator:
        p:phase, dp:change of phase/pixel, f:change of phase/second
      angle:
        a:phase, w:change of phase/second

starfield:
----------
  status list
  move list


palette:
--------
  time/sec palcommand
  time/sec palcommand
  ...
  10000


palcommand:
-----------
one of the below:
  -setpali                 basecol colnum  sr sg sb  er eg eb
    interpolates the colors from color basecol to color basecol+colnum-1
      from  sr sg sb  to  er eg eb
  -fadepali deltatime/sec  basecol colnum  sr sg sb  er eg eb
    crossfade (see setpali)