Visualization with VTK tools (e.g. Paraview or VisIt)

Since 3-D models can be very hard to visualize, and since RADMC-3D is not made for quick rendering, it can be very useful to make use of a number of freely available 3-D rendering tools, for example:

Paraview www.paraview.org
VisIt visit.llnl.gov

RADMC-3D can create data files for use with these tools. The file format is VTK (Visual Tool Kit), which is a simple ascii file format which is used by various programs. Those tools are not only useful for visualizing the 3-D structure of the model, but also for visualizing the structure of the grid which can be, when using AMR, rather complex.

The file that RADMC-3D writes is called model.vtk. You should be able to open it directly from within e.g. paraview. Figures Fig. 28 and Fig. 29 gives an example of how you can analyze a complex geometry with AMR refinement with Paraview. The file {em always} includes the information about the grid. In addition you can also make RADMC-3D add scalar fields or vector fields.

To create a VTK file for viewing the grid only, type:

radmc3d vtk_grid

To create a VTK file for viewing the gas density (this file then also includes the grid of course) type:

radmc3d vtk_gas_density

Since density can span a huge range, the 10-log of the density (in units of gram/cm\(^3\)) is written instead. For the gas temperature:

radmc3d vtk_gas_temperature

which is written in Kelvin (and linearly, not log). For the dust density of dust species 1:

radmc3d vtk_dust_density 1

and for dust species 2:

radmc3d vtk_dust_density 2

Also these densities are 10-log. RADMC-3D typically computes the dust temperature using a Monte Carlo approach. By typing

radmc3d vtk_dust_temperature 1

RADMC-3D will try to read the dust temperature from the file dust_temperature.dat (if this file has been created earlier by a radmc3d mctherm call) and then create the VTK file. You can also let RADMC-3D compute the temperature directly and write it out to VTK right afterward:

radmc3d mctherm vtk_dust_temperature 1

If you are doing line transfer you may wish to visualize the number density of the molecules (or atoms):

radmc3d vtk_molspec 1

(for molecular species 1). This number density (in cm\(^{-3}\)) is also written in 10-log form. You may also wish to visualize the polulations of level 1 (ground state) of molecule 2:

radmc3d vtk_levelpop 2 1

The gas velocity field can be written to VTK file by

radmc3d vtk_velocity

This is a vector field.

Note: The VTK mode works for 3-D cartesian and 3-D spherical coordinates (thanks, Attila Juhasz, for the 3-D spherical mode!).