Directions¶
Open the Directions dialog with Crystallography → Add Directions (Ctrl+Shift+D).
Crystallographic direction vectors are rendered as lines, arrows, or cylinders overlaid on the crystal. They can represent growth directions, slip directions, or any other vectors of interest.
Coordinate Modes¶
| Mode | Input | Requires |
|---|---|---|
| Fractional [u v w] | Integer direction indices | Lattice parameters set |
| Cartesian | Float vector (x, y, z) | Nothing |
Switch modes with the Fractional / Cartesian selector. If lattice parameters have not been set and you select Fractional mode, a warning is shown. See Lattice Parameters.
Adding a Direction¶
- Select the coordinate mode
- Enter the [u v w] or (x, y, z) components
- Optionally set an Origin (start position offset)
- Choose a Rendering Style (Line, Arrow, or Cylinder)
- Set Thickness (1.0–100.0)
- Set Length (0.1–5.0× crystal extent)
- Choose a Colour (auto-assigned by indices)
- Adjust Opacity
- Click Add Direction
Rendering Styles¶
| Style | Description |
|---|---|
| Line | Flat 2D line. Fastest, always visible. |
| Arrow | 2D arrow with arrowhead at the endpoint. |
| Cylinder | 3D cylinder with a cone arrowhead. Lighting-shaded. |
Arrow and Cylinder styles make direction clearer in 3D but are slower to render than Line.
Direction List¶
All added directions appear in the direction list. Select a direction to edit its properties, or use:
- Remove Selected — delete the selected direction
- Clear All — remove all directions
Converting a Direction to a Plane¶
Select a direction in the list and click Add as Plane. This creates a new plane in the Planes dialog with a normal equal to the selected direction vector.
Appearance Settings¶
| Setting | Range | Description |
|---|---|---|
| Thickness | 1.0–100.0 | Line/cylinder pixel width |
| Length | 0.1–5.0× | Length relative to crystal extent |
| Colour | RGB picker | Auto-assigned by indices |
| Opacity | 0–255 | Transparency |
Colour Auto-Assignment¶
Directions are automatically assigned distinct colours based on their index values, making it easy to visually distinguish multiple directions. Colours can be overridden with the colour picker.