Selecting

This page discusses specific selecting tools for curve objects in Edit Mode. The Curve Edit more also uses the general select tools used which are described in the interface section.

Curve selection in Edit Mode has fewer options than with meshes. Mainly this is, because there is only one selectable element type, the control points (no select mode needed here...). These points are a bit more complex than simple vertices, however, especially for Bézier curves, as there is the central vertex, and its two handles...

The basic tools are the same as with meshes, so you can select a simple control point with the LMB, add to current selection with Shift-LMB, Box Select B, and so on.

One word about the Bézier control points: when you select the main central vertex, the two handles are automatically selected too, so you can move it as a whole, without creating an angle in the curve. However, when you select a handle, only this vertex is selected, allowing you to modify this control vector...

Note that, unlike mesh edges, you cannot directly select a segment. Instead, select all of the control points that make up the segment you want to edit.

Select Menu

With curves, all "advanced" selection options are grouped in the Select menu of the 3D Viewport header.

All A: Select all.
None Alt-A: Select none.
Inverse Ctrl-I: Selects all the geometry that are not selected, and deselect currently selected components.

Box Select B: Interactive box selection.
Circle Select C: Interactive circle selection.
Lasso Select: Interactive free-form selection.

Select Random: Select random control points.
Checker Deselect: Select every Nth control point.
Select Linked Ctrl-L: Select control points that are connected to the current selection.
Select Similar Shift-G: Select control points that have similar properties to the current selection.

(De)select First/Last: Toggle the selection of the first or last control point(s).
Select Next/Previous: Selects the next or previous control points.

Select More/Less: Select objects based on their parent child relationships.

Select Random

Reference

Mode: 編輯模式
選單: Select ‣ Select Random

Select Random control points.

百分比值（Percent）: Selects the defined percentage of control points.
Random Seed: Seed used by the pseudo-random number generator.
Action: Controls whether the operator Selects or Deselects control points.

Checker Deselect

Reference

Mode: 編輯模式
選單: Select ‣ Checker Deselect

This tool applies an alternating selected/deselected checker pattern. This only works if you already have more than one control point selected.

It works by changing the current selection so that only every Nth control points will remain selected, starting from the active one.

Deselected: The number of deselected elements in each pattern repetition.
Selected: The number of selected elements in each pattern repetition.
偏移量（Offset）: Offset from the starting point.

Select Linked

Reference

Mode: 編輯模式
選單: Select ‣ Select Linked
Shortcut: L, Ctrl-L, Shift-L

L (or Ctrl-L for all) will add to the selection the cursor's nearest control point, and all the linked ones, i.e. all points belonging to the same curve. Note that for Bézier, using L with a handle selected will select the whole control point and all the linked ones.

Select Similar

Reference

Mode: 編輯模式
選單: Select ‣ Select Similar
Shortcut: Shift-G

Selects control points that have certain similar properties to the active one. The Adjust Last Operation panel provides several selection options:

Type

Type: Selects splines that have the same spline Type i.e. Bézier, NURBS or Poly.
Radius: Selects control points that have a similar Radius value.
權重: Selects all points that have a similar Weight value.
Direction: Selects control points that have a similar handles direction.

Compare

For quantitative properties, this property selects the type of comparison to between the two numerical values.

Equal: Select items with the same value as the active item's chosen property.
Greater: Select items with a larger value as the active item's chosen property.
Less: Select items with a smaller value as the active item's chosen property.

Threshold

For quantitative properties, this property controls how close the property's values have to be in the comparison.

(De)select First/Last

Reference

Mode: 編輯模式
選單: Select ‣ (De)select First, Select ‣ (De)select Last

These operators will toggle the selection of the first or last control point(s) of the curve(s) in the object. This is useful to quickly find the start of a curve (e.g. when using it as path...).

Select Next/Previous

Reference

Mode: 編輯模式
選單: Select ‣ Select Next, Select ‣ Select Previous

These operators will select the next or previous control point(s), based on the current selection (i.e. the control points following or preceding the selected ones along the curve). In case of a cyclic curve, the first and last points are not considered as neighbors.

Select More/Less

Reference

Mode: 編輯模式
選單: Select ‣ More/Less
Shortcut: Ctrl-NumpadPlus, Ctrl-NumpadMinus

Their purpose, based on the currently selected control points, is to reduce or enlarge this selection.

More: For each selected control point, select all its linked points (i.e. one or two...).
Less: For each selected control point, if all points linked to this point are selected, keep this one selected. Otherwise, deselect it.

This implies two points:

When all control points of a curve are selected, nothing will happen (as for Less, all linked points are always selected, and of course, More cannot add any). Conversely, the same goes when no control points are selected.
Second, these tools will never "go outside" of a curve (they will never "jump" to another curve in the same object).

Pick Shortest Path

Reference

Mode: 編輯模式
選單: Menu Search ‣ Pick Shortest Path
Shortcut: Ctrl-LMB

Selects the curve segments between two control points: the active and the one under the cursor. In the case of a closed curve, the shortest path will be selected.