This directory contains example "director" and param files for making movies
with ChaNGa.  Below is an explanation of the parameters.

dDumpFrameTime       timestep of dumps
Command line  +dft dt
dDumpFrameStep       step number of dumps
Command line  +dfi dstep

If trying to do a single output time fly around use a very small dDumpFrameTime, e.g.:
bDoGravity = 0   (optional)
dDumpFrameTime = 1e-6
Where 1e-6 is much smaller than any time scale in the simulation

Frame camera parameters are interpolated using 4 points (2 either side
of the exact frame time) if available.  Otherwise as many points as are available
are used down to simple linear interpolation.  Not all parameters
are amenable to interpolation.

e.g. Image size is not interpolated

If a parameter is not interpolated it just changes to the new value
when the frame time equals or passes the time point.

Time points for camera parameters are specified in the director file.
Each time the keyword "time" is specific a new point is created
and each parameter changed after than point refers to that time.

You must specify a first time point before the start of the simulation
to interpolate smoothly.

.director file:

GLOBAL SETTINGS

dim [2|3]  
  dimensions 
  3 is not fully implemented yet
  default: 2

file basefilename
  base file name for outputs    e.g basename = fabio, 
  outputs will be something like fabio.0001.ppm, fabio.0002.ppm, ...
  default: Frame
  
gas off
gas minmass maxmass
  Gas particle cuts
  default: all gas

dark off
dark minmass maxmass
  Dark particle cuts
  default: all dark

star off
star minmass maxmass
  Star particle cuts
  default: all stars

encode [ppm|png|rle|treezip]
  ppm -- ppm files (DEFAULT)
  png -- png files (-DUSE_PNG and -lpng -lz to use png library, see pkdgrav Makefile and uncomment PNG_ lines)

numbering [frame|step|time] [format]
  frame -- count frames ("%09i") (DEFAULT)
  step  -- step numbers ("%012.6f")
  time  -- simulation time ("%012.6f")
  format -  c style format string

FRAME_BY_FRAME SETTINGS

time X
  time for the frame parameters to apply at
  This is simulation time

target x y z
  target point for view
  default: 0 0 0

eye rel|abs
  rel means the eye is positioned relative to the target point (default)
  abs means the eye is positioned in absolute coordinates

eye1 x y z 
OR
eye x y z 
  eye point (camera position)
  Technically is is eye1 (but eye2 defaults to zero) so by default this sets the fully
  camera position.
  Saying "eye" or "eye1" is equivalent.
  The magnitude of this vector can be renormalized to zeye1 (if non-zero)
  The TOTAL magnitude of the eye vector (eye+eye2) is renormalized to zeye (if non-zero)
  default: 0 0 -.5

eye2 x y z
  secondary eye vector -- added to the first eye position (eye1)
  Can be useful for complicated camera trajectories
  The magnitude of this vector can be renormalized to zeye2 (if non-zero)
  The TOTAL magnitude of the eye vector (eye1+eye2) is renormalized to zeye (if non-zero)
  default: 0 0 0

up x y z
  up direction for screen
  default: 0 1 0

size nx ny
  size of image
  default: 800 600

zeye x
  how far away the camera is from target
  the eye position is just used to determine a vector direction in this case
  applied to total camera vector (eye1+eye2)
  default: 0 (OFF)

zeye1 x
  constraint on distance to camera
  applied to first part of total camera vector (eye1)
  default: 0 (OFF)

zeye2 x
  constraint on distance to camera
  applied to second part of total camera vector (eye2)
  default: 0 (OFF)

FOV x
  width of the viewing area in degrees (e.g. 60-90)
  Larger fields of view tend to enhance the perspective effects
  Fields of view larger than 120 may result in very distorted images
  default: 90

loop t0 dt
  starts looping in time at t0 with a period dt
  So at t0+dt it starts repeat the directions for t0
 
clip znear zfar
  Z clipping planes
  How close or far things get to camera before they disappear
  default: 0.01 2.0

project [ortho|perspective]
  projection method
  default: perspective

colgas r g b [scale]
  Colour of gas particles
  Scale is typically comparable to a particle mass; smaller means brighter
	colours.
  default: 1.0 0.7 0.5

coldark r g b [scale]
  Colour of dark particles
  Scale is typically comparable to a particle mass 
  default: 0.5 1.0 0.7

colstar r g b [scale]
  Colour of star particles
  Scale is typically comparable to a particle mass 
  default: 0.5 0.7 1.0

colmass [scale]
  Set scale for all particle types

logscale logmin logmax
  set scaling for colours from the projected column densities
  converts input colors to final colours.
  logmin is the column density that maps to "0" pixel value
  logmax is the column density that maps to the saturated pixel value.
  default: OFF
  
softgassph
  use sph softening lengths for gas projection
  default: TRUE

softgas softmul 
  set gas softening multiplier
  default: 1 (OFF)

softdark softmul
 set dark softening multiplier
  default: 1 (ON)

softstar softmul
  set star softening multiplier
  default: 1 (ON)

render [point|tsc|solid|shine]
  point -- render points (black and white) (DEFAULT)
  tsc   -- softened points using softening radius and Triangular Shape Clound function
  solid --
  shine --