Data Editing

Editing

After acquiring some information from the scanner, there might be the need to clean the data from unwanted parts or from noises, or the need to remove some unwanted parts from a mesh.

Selecting Data

To remove any part of an image, first select it. Use the Selection Tools that work on both, acquisitions and meshes, or use one of the Select Outliers functions that work only on acquisitions.

Selection Tools

The selection tools are interactive tools that can be used dragging the mouse on the 3D View and holding the left button of the mouse. A shape will appear, following the mouse, and all the information inside its borders will be selected.

The tools are:

• Rectangular: draws a rectangle that starts from the click point and grows following the mouse; the selection is performed releasing the left mouse button
• Elliptical : draws an ellipse centered in the click point that grows following the mouse; the selection is performed releasing the left mouse button
• Polygonal : click one time to create a point, every new click adds one point. From the third point, it creates a polygon. Double click to close the polygon and select all the area inside its borders
• Free Closed Line : click and hold the left mouse button to start drawing a line that follows the mouse. Release the left mouse button to close the line and select all the area inside its borders
• Free Open Line : click and hold the left mouse button to start drawing a line that follows the mouse. Release the left mouse button to select all the data exactly below the drawn line
• Segment : click and hold the left mouse button to start drawing a straight line between the click point and the current position of the mouse. Release the left mouse button to select all the data exactly below the segment.

Unselect Data

Hold the CTRL button to unselect data instead of selecting it.

Pass-Through Selection

The Pass through (CTRL+ALT+V) option, located in the 3D View Context Menu , changes how the selection works only on meshes.

If this option is disabled, only the visible part of the mesh will be selected by the selection tools. All the hidden parts, or the parts on the other side of the object, will not be selected.

If the option is enabled, all the data inside the selection tool shape will be selected, even if not visible or hidden behind other mesh surfaces.

Outlier Cleaning

Outliers are all the points of an acquisition that are not part of the object surface. They can be noises, reflections on the object surfaces or acquisition artefacts.

Each acquisition strategy already applies a specific outlier cleaning. Therefore, data are often ready to be aligned and converted in mesh directly after the acquisition.

In order to further remove outliers, use one of the three Select Outliers tools.

Select Outlier

This is the easiest tool; it tries to identify all the points that are alone, far from all the other points. Click on this tool button to open a window containing two parameters

• Selectivity : how many points have to be one near each other to understand if a point can be considered alone or not. High value means more points selected
• Strength : how close two points have to be to be considered not alone. High value means more points selected

When changing the parameters, the software will show the selection in real time. Click ok to confirm the selection.

Select Outlier by Angle

This tool works in a similar way to the Select Outlier tool, but only one parameter is provided: an angle. A point is considered an outlier only if there are no point near it that create an angle smaller than the parameters. This means that a smaller angle corresponds to more points selected.

When changing the parameters, the software will show the selection in real time. Click ok to confirm the selection.

Select Outlier Segmentation

This tool works in the same way as the Select Outlier tool but analyses blocks of points and not single points.

Base Selection

To remove the Base of the acquisition (the part of the acquisition near the model holder) use the Cut Height Acquisition Tool.

A slider will appear, which controls a height value. All the points below the chosen height will be selected.

When moving the slider the software will show the selection in real time. Click ok to confirm the selection.

Editing Functions

When a selection is performed, use one of the following editing functions from the 3D View Context Menu, from the Edit Menu or the related keyboard shortcuts:

• Delete Selection (DEL) : deletes the currently selected data
• Crop Selection (CTRL + K) : keeps only the selected data and removes all the rest
• Invert Selection (CTRL + I) : selects all the data that is not selected and deselects the selected data
• Clear Selection (CTRL + C) : deselects all the data
• Select All (CTRL + SHIFT + C) : selects all the data
• Select Connected (ALT + SHIFT + D) : (only for meshes) extends the selection to get all the parts connected to the current selection area
• Dilate Selection (CTRL + D) : extends the selection a little bit to the data close to the actual selection
• Erode Selection (CTRL + SHIFT + D) : reduces the selection a little bit from the margin of the actual selection

Next

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