Edit Point Cloud Along Line¶
Use this dialog to edit points in a section normal to a line. This can be a line in an application layer, a line in an SFI model, or a temporary line that you construct on the spot. The function is used for example to delete noise in a tunnel scan or a point cloud from a drone.
Where do I find the dialog?¶
In the context menu in terrain model drawing (when point cloud and line are selected on screen), choose Tools - Edit point cloud along line...
Using the dialog¶
If you only select a point cloud, you will be asked to create a temporary line. If you select both point cloud and line before choosing the function, you go directly into the dialog.
You can display point clouds from other application layers as background. These background point clouds are shown in gray and are not editable.
Before you select Edit point cloud along line..., you must also select point clouds in other application layers if you want to use these as background point clouds. The point clouds in the active application layer are the ones being edited, while those in other application layers are displayed as background.
In the dialog, you specify the current profile, optionally distance to left and right, as well as the selection depth. If you choose for example profile 7280 and selection depth 1.5, points 0.75 forward and backward will be included.
Point cloud editing is a manual and often time-consuming process that can involve much time with repetitive operations.
Most users – especially those familiar with PC games – naturally rest their left hand around the WASD area on the keyboard, with the right hand on the mouse.
All choices in the dialog therefore have keyboard shortcuts according to this hand position on the context menu, so that unnecessary hand movements are minimized.
| Function | Keyboard Shortcut |
|---|---|
| Browse forward | [W] |
| Browse backward | [S] |
| Select with polygon | [Spacebar] |
| Flip selection | [X] |
| Delete | [R] |
| Increase number of pixels | [E] |
| Reduce number of pixels | [Q] |
| Increase selection depth | [D] |
| Reduce selection depth | [A] |
Cross-section generation "on the fly"¶
The program can triangulate and generate a section for the current profile number. The prerequisite is that a layer is selected for the application layer, for example 91: Tunnel. First, you must activate 3D triangulation under Triangulation parameters.... Then you can check Show calculated cross-section. The points you see in 3D view can automatically give you a view of the point selection normal to the centerline with this choice.
By default, the points are displayed with red color. You can choose to use colors from the application layer, that is Solid color, Color from RGB, or Color from intensity. If Color from height is defined in the application layer, the color closest to 0 will be used, since Z is distance forward/backward in the profile.
To select points on screen, you can use standard CAD functions or Select points with polygon... ([Backspace]). Click in the points in the polygon with the left mouse button and close the polygon with [Enter]. When you choose the function, any selected points are deselected (the function resets the selection).
The button Delete point selection ([R]) is used to delete selected points, typically noise in the point cloud.
Example
In this section you can see the contours of some equipment that you want to remove.
Select these points that you want to remove, either with polygon or standard DDSCad selection (hold down the left mouse button and drag).
Press Delete point selection or keyboard shortcut [R].
Standard DDSCad selection¶
Multiple points can be selected simultaneously with a dynamic rectangle. Point to the upper left corner of an imaginary rectangle. Left-click and hold down the mouse button. A rectangle with dashed lines appears. Drag the rectangle down to the right and release the mouse button when the desired points are inside. If you want to add more points, you can hold down the [Ctrl] key. Similarly, you can remove points from the selection by dragging a rectangle down to the left.
Note that you must hold down the [Shift] key if you select points in 3D view (overrides rotation). This may be relevant if you have activated the icon for perspective view.