Triangles Selector selects triangles of a mesh. Its main strength is a selection border drawn on the surface of the model, which follows the shape instead of the screen. In older versions and guides the tool was called Face Selector.
How to open Triangles Selector
- Select a mesh in the Scene Tree. The tool works with meshes only; for point clouds use Select Primitives.
- On the Select tab, open the drop-down arrow next to Select Primitives and choose Triangles Selector.
- In the panel, choose a Mode and select in the viewport with the left mouse button. Selected triangles are drawn in the color of the Color of selected triangles swatch (red by default).
Triangles Selector or Select Primitives?
| You need to | Use |
|---|---|
| Select inside a border that runs along the surface, for example around a tooth, a bracket or a feature on a curved model | Triangles Selector, mode Polygon Model or Loop Model |
| Select everything inside a shape on the screen, on a mesh or a point cloud | Select Primitives (Lasso, Rect, Polygon) |
| Paint a selection with a brush | Either tool: Brush Screen here, Brush in Select Primitives |
| Select edges instead of triangles | Edge Selector |
For a worked example, see Removing brackets from a dental mesh scan.
Selection modes
Choose the mode in the Mode list. The default mode is Loop Screen.
Single face
Click a triangle to select it. Use it for precise, one-by-one corrections.
Polygon Model
Click points on the model. The border between them is drawn on the surface. To finish, click the first point again or press Enter; the area inside the border is selected.
Loop Model
Hold the left mouse button and draw around the area. The border is drawn on the surface and follows the shape of the model.
Line Width and Curvature Preference
Polygon Model and Loop Model have two extra settings:
| Setting | What it does | Default |
|---|---|---|
| Line Width | Width of the border drawn on the surface, 0.5 to 5 px. It changes only the display, not the selection. | 1 px |
| Curvature Preference | How the border runs between your points: Geodesic takes the shortest path; Convex takes a longer path through convex regions; Concave takes a longer path through concave regions. | Geodesic |
Loop Screen
Hold the left mouse button and draw a closed loop on the screen. Triangles inside the loop are selected.
Brush Screen
Hold the left mouse button and paint over the area. Triangles under the brush are selected. Brush radius sets the brush size, 1 to 500 px (default 8 px).
Select Back Triangles and Select Only Visible
In Loop Screen and Brush Screen modes two checkboxes control what the screen shape catches. Both are on by default.
- Select Back Triangles also selects triangles that face away from the camera.
- Select Only Visible skips triangles hidden behind other surfaces.
Modifier keys
The panel lists the keys under Hold. Hold the key while you click or draw:
| Key | Result |
|---|---|
| No key | Replaces the previous selection. |
| Ctrl (Cmd on macOS) | Adds to the previous selection. |
| Shift | Removes from the previous selection. |
| Ctrl+Shift (Cmd+Shift on macOS) | Reverses the selection inside the new area. |
If Settings › Application › Default Selection Behavior is set to Append selection, no key adds to the selection and Ctrl (Cmd) replaces it.
When the area is selected, continue with Delete Selected, Selection to Object or Expand Selection.
