Planes¶

Open the Planes dialog with Crystallography → Add Planes (Ctrl+Shift+L).

Crystallographic planes are displayed as semi-transparent quads overlaid on the crystal. They can also be used to slice the point cloud.

Coordinate Modes¶

Mode	Input	Requires
Miller (h k l)	Integer Miller indices	Lattice parameters set
Cartesian Normal	Float vector (nx, ny, nz)	Nothing

Switch modes with the Miller / Cartesian selector in the dialog. If lattice parameters have not been set and you select Miller mode, a warning is shown. See Lattice Parameters.

Adding a Plane Manually¶

Select the coordinate mode (Miller or Cartesian)
Enter the h/k/l or nx/ny/nz values
Optionally set an Origin (X, Y, Z offset in world space)
Set Size (relative to crystal extent, 0.1–5.0×)
Choose a Colour (auto-assigned by indices, or pick manually)
Adjust Opacity (0 = transparent, 255 = opaque)
Click Add Plane

The plane appears in the viewport and is added to the plane list.

Reduce Button¶

Click Reduce to simplify Miller indices by their GCD (e.g., 2 4 2 → 1 2 1). This has no effect on the Cartesian normal.

Finding a Plane from Points¶

You can fit a plane to three or more selected points in the viewport:

Click Find Plane in the dialog
The dialog hides. Shift+Click to select 3 or more points in the viewport
Click Confirm (in the Find Plane toolbar that appears)
The fitted plane is added to the list

This is useful when you want to identify the plane through specific crystallographic sites.

Plane List¶

All added planes are shown in the plane list. Select a plane to:

Edit its properties (origin, size, colour, opacity)
Enable slicing (see Slicing)
Remove it with Remove Selected

Clear All removes every plane.

Converting a Plane to a Direction¶

Select a plane in the list and click Add as Direction. This creates a new direction vector with the same normal vector as the selected plane in the Directions dialog.

Plane Appearance¶

Setting	Range	Description
Size	0.1–5.0×	Size relative to crystal extent
Colour	RGB picker	Auto-assigned by indices; can be overridden
Opacity	0–255	Transparency of the quad

Cell Parameters Display¶

The current lattice parameters (a, b, c, α, β, γ) are shown at the top of the dialog for reference. They can be changed in Lattice Parameters.