2.8.3. Choosing levelmax

For sink-centered local models, a lower levelmax is often good enough for visual work and can be much cheaper.

For run='20z-18s180-395NIMHD', iout=440, sink=178, using the same physical box and the same rendered image:

  • levelmax=18, npix=32: export about 0.7 s, image about 0.3 s

  • levelmax=19, npix=64: export about 2.5 s, image about 1.4 s

  • levelmax=20, npix=128: export about 23 s, image about 8.3 s

These images were compared at:

  • 128 x 128 pixels

  • 300 micron

  • sizeau=100

In the validated case, levelmax=19 was visually close to 20 while reducing end-to-end time from about 31 s to about 4 s.

  • start with levelmax=19 for sink-centered disk images

  • use levelmax=20 if peak brightness or inner structure matters

  • use levelmax=18 mainly for quick previews

The figure below compares the validated levelmax=18, 19, and 20 images for the same sink-centered box and the same rendered image plane:

Comparison of sink-centered RADMC-3D images for levelmax 18, 19, and 20

At about 128^3 voxels, the difference is noticeable but still modest for a single run. It becomes more relevant around 256^3 and very relevant around 512^3 or larger, especially if you run many snapshots or multiple images per thermal model.