How to use Volume map

Volume map puts a voxel overlay on the 3D reconstruction. Use it for concentration, ion density, peak ratios, or multiplicity. Load a POS, EPOS, or APT file with reconstructed XYZ, apply your ranges, then click Volume map on the toolbar.

Compute a map

1. Click Volume map.
2. Choose Quantity:
   • Concentration (at.%) — composition of one ion or element on the voxel grid.
   • Ion density (ions/nm³) — number density.
   • Peak ratio A/B or A/(A+B) — ratio of two RRNG isotope peaks.
   • Multiplicity density (hits/nm³) — needs an EPOS file. See How to use multiplicity density volume maps.
3. Pick the ion, or the two peaks for a ratio. For concentration, the grid is computed once for all elements; you can switch Ion afterwards without recomputing.
4. Set Voxel (nm), Display grid (default 1024, up to 2048), and Delocalization (nm).
5. Click Compute grid.
6. Display can be Volume or Slice. Adjust the colormap, Min/Max, Highlight high values, and Clip outside reconstruction as needed.

After the map is computed

• The overlay stays in the 3D view when you close the settings window. The toolbar checkbox shows or hides it.
• Export CSV and Export VTK write the grid.
• If you edit RRNG, click Update analysis (or Apply to Analyses) so the map follows the new ranges.
• Slice clips the original map to the slab; it does not rebuild the voxels from the sliced ions. Show all restores the full map.