director.README
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 --