Movies

The block named &MOVIE_PARAMS contains the parameters related to the movies. One can produce up to 5 movies, which center at different parts of the simulation box and have various camera behavior (see example blocks in the bottom).

The movie routine is very useful for creating on the fly visualizations of a simulation with a small time step between frames, without having to write and process many huge snapshots for that. For turning the binary images created by this routine into a movie that can be watched on any media player, check out RAM.

Variable name, syntax, default value	Fortran type	Description
movie	boolean	Turns movies on and off
imov	integer	Number of starting frame
imovout	integer	Total number of frames
tstartmov	float	Start time of the movie
astartmov	float	Start aexp of the movie
tendmov	float	End time of the movie
aendmov	float	End aexp of the movie
levelmax_frame	integer	Maximum level of the frame
nw_frame	integer	Width of frame in px
nh_frame	integer	Height of frame in px
xcentre_frame	5*float, float, float, float	Four (for each projection) coordinates for z position of frame centre [code units] - spline coefficients
ycentre_frame	5*float, float, float, float	Four (for each projection) coordinates for y position of frame centre [code units] - spline coefficients
zcentre_frame	5*float, float, float, float	Four (for each projection) coordinates for z position of frame centre [code units] - spline coefficients
deltax_frame	float, float	Two coordinates for x delta of frame [code units]
deltay_frame	float, float	Two coordinates for y delta of frame [code units]
deltaz_frame	float, float	Two coordinates for z delta of frame [code units]
zoom_only_frame	5*boolean	Consider only particles in the zoom region of cosmological runs
proj_axis	5*character	Letter code of projection axis; x, y, z - maximum 5 line of sights
movie_vars_txt	strings	Determines which variables to save - dens, temp, pres, vx, vy, vz, varX, FpX (RT-only), stars (star particles), dm (dark matter particles), lum (stellar luminosity)
theta_camera	5*float	Azimuthal angle of the camera with respect to the line of sight [degrees]
phi_camera	5*float	Polar angle of the camera with respect to the line of sight [degrees]
dtheta_camera	5*float	Azimuthal angle rotation completed between tstartmov and tendmov [degrees]
dphi_camera	5*float	Polar angle rotation completed between tstartmov and tendmov [degrees]
focal_camera	5*float	Distance of the focal plane of the camera [code units]. Camera distance is set to boxlen and focal_camera is set to boxlen by default.
dist_camera	5*float	Distance of the camera [code units]. Camera distance is set to boxlen and focal_camera is set to boxlen by default.
ddist_camera	5*float	Motion of the camera between tstartmov and tendmov [code units]
perspective_camera	5*boolean	Perspective corrections for the projected cells
shader_frame	5*strings	Shader applied for the leaf cells projection [square, sphere, cube]
ìvar_frame	5*integer	Index of hydro variable to use for selecting cells to project (default=-1)
varmin_frame	5*integer	Only project cells within varmin_frame<uold(*,ivar_frame)<varmax_frame. Density is expressed in cm^-3, velocities in km/s, temperature in K/mu, all other hydro variables in code units.
varmax_frame	5*integer	Only project cells within varmin_frame<uold(*,ivar_frame)<varmax_frame. Density is expressed in cm^-3, velocities in km/s, temperature in K/mu, all other hydro variables in code units.
method_frame	5*strings	Available projection methods: mean_mass (default), mean_dens, mean_vol, sum, min, max

Examples:

• cosmological simulation

#!fortran
&MOVIE_PARAMS
movie=.true.
imov=0
aendmov=1.
imovout=1000
nw_frame=1920
nh_frame=1080
levelmax_frame=18
xcentre_frame=0.49944825,-0.00391524,0.02661462,-0.01714339
ycentre_frame=0.49512072,0.00498905,-0.01826436,0.01097619
zcentre_frame=0.483284613,0.0246328776,-0.0149075526,-1.06750114e-04
deltax_frame=0.0,0.001
deltay_frame=0.0,0.0005625
deltaz_frame=0.0,0.001
proj_axis='z'
movie_vars_txt='dm','stars','temp','dens','var6'
/

This will result in 1000 frames 1920x1080 (Full HD) between starting redshift and z=0. Values for xcentre_frame, ycentre_frame and zcentre_frame come from fitting the spline coefficients with utils/py/get_spline_coeffs.py (it requires previous run of the same setup with clump finder; e.g. DM-only). Size of the frame will be reflecting physical units (e.g. delta_x=deltax_frame[0]+deltax_frame[1]/a; where a is the explansion factor). Frames are going to be projected along the z axis and projections of dark matter density, stellar density, temperature, gas density and var6 (extra variable, here metallicity) will be saved.

• non-cosmological

#!fortran
&MOVIE_PARAMS
movie=.true.
imov=0
tendmov=10.
imovout=1000
nw_frame=1920
nh_frame=1080
levelmax_frame=14
xcentre_frame=5.0,0.,0.,0.,5.0,0.,0.,0.
ycentre_frame=5.0,0.,0.,0.,5.0,0.,0.,0.
zcentre_frame=5.0,0.,0.,0.,5.0,0.,0.,0.
deltax_frame=1.0,0.,1.0,0.
deltay_frame=1.0,0.,1.0,0.
deltaz_frame=1.0,0.,1.0,0.
proj_axis='zy'
movie_vars_txt='dm','stars','temp','dens','var6'
/

Same variables as for the cosmological run are going to be saved with the same resolution. Here, the camera is always centred at the centre of the box (assuming boxlen=10) and encompasses volume of 10% x 10% x 10% of the box. Tendmovie is set in the code units of time.