Tool >> Extract Exterior Region  

• Tool >> Extract Exterior Region command extracts exterior region of a shell. It can be used on volume reconstructed shell or shell of multiple layers.

Step

Execute Tool >> Extract Exterior Region command as follows.

1. Select Tool >> Extract Exterior Region from the menu.

2. Pick a shell.

3. After preprocessing, the following dialog box appears:

The parameters in Region Search section are used to extract the exterior region of the picked shell.
If Use Custom Initial Condition is checked, you can specify Initial Radius value. If a big enough value is given, only the exterior region can be selected. In case of an open shell, you can mark the region not suitable for finding the exterior region, then check on Ignore Marked Vertices.
Expand Radius is used to expand the region found above. According to the profile of the picked shell, you should give different radius value. Tolerance is the margin used to expand the region. By default, Expand Radius is three times of the average edge length and Tolerance is 30% of the average edge length.
If Search Region button is clicked, the exterior region will be searched.

The commands in Region Modification section are used to modify the automatically found region.
If Expand is clicked, the selected region will be enlarged one depth. If Shrink is clicked, the selected region will be shrunk by one depth. If Flood Fill is selected, you have to select a seed face and the faces within the same boundary will be selected. If Paint Brush is clicked, you can paint select faces. If Undo is clicked, the last selected region will be deselected. If Redo is clicked, the last deselected faces will be selected again. Here Undo/Redo has only one depth.

The options in Selected Region Options are used to post-process the found region.
If Keep is checked, the found region will be selected, nothing else will be done. If Delete is checked, the found region will be deleted. If Copy to New Shell is checked, the found region will be copied to a new shell. If Cut & Paste to New Shell is checked, the found region will be copied to a new shell, and then it will be removed from the original shell.

4. Click OK to extract the exterior region. Otherwise click Cancel to quit this operation.