The Inspector Tool is used to repair a few common mesh problems. It is focused on errors that occur in 3D scans, rather than all issues that might need to be resolved to create a printable solid. The example below shows an imported scan. Running Inspector highlights all the issues, with color-coded stick/ball indicators. Inspector can automatically resolve all these issues, leading to an error-free water-tight model on the right.
The hotkey for the Inspector tool is i.
The property panel for Inspector is shown to the right. There are only a few controls, and in most cases you will not need to modify them. The Fill Mode and Small Thresh are shown below.
When using the Inspector, you can left-click on the balls to attempt to repair the indicated problem. Alternately you can right-click or shift-left-click on a ball to exit Inspector and initialize the Select Tool with the problematic region highlighted. This is useful if you would like to manually repair a region.
Finally, clicking the Auto Repair All button will tell Inspector to attempt to repair each detected issue sequentially. This can take some time if there are many problems.
How It Works
Inspector only attempts to deal with three simple problems in the mesh. The goal of the repair strategies is to create a closed mesh that has no holes or non-manifold areas. Also, small floating components will be discarded.
The image below shows an example of each problem type. Blue highlights represent holes in the mesh. The auto-repair attempts to fill holes using the strategies of the Erase & Fill Tool.
Red highlights indicate non-manifold regions. Non-manifold elements are "bowtie" vertices or edges with more than two connected triangles. Note that we merge overlapping artifacts into the "worst-case" option, so in the example below, the bowtie vertex overlaps a hole, and hence the entire hole is marked as non-manifold. To repair a non-manifold region, we first delete the triangles highlighted in red, and then attempt to fill the resulting hole.
Magenta highlights indicate small-component areas. These regions are simply deleted. We identify small components as having a small surface area relative to the total model surface area. The default threshold is 1%.
We mentioned above that Holes and Non-manifold regions are repaired by filling holes (either existing or created by deleting triangles). If this fails for some reason, our strategy is to erode the hole by one ring of triangles and try again. This is repeated several times for each problem area. However, these repairs strategies can still fail. If you left-click a sphere and the repair fails, it will turn grey, as shown in the image below. In this case the only fallback is to right-click to select this area, and try to repair it manually.
Hole Fill Mode
The Hole Fill Mode parameter is identical to the Fill Type in the Erase & Fill Tool. See that page for more details on each. However they are renamed in Inspector (to, frankly, more sensible names!). Minimal fill is Flat Minimal mode, Flat Fill is Flat Remeshed, and Smooth Fill is Smooth MVC.
The Small Thresh parameter specifies the threshold for what is detected as a "small component". These areas are deleted by the auto-repair. This can be a disaster if your mesh just happens to contain small parts. For example in the image below-left, some of the geometric features like buttons, fingernails, and the pocket are separate overlapping shells. They have been detected as "small" and would be deleted. By reducing the Small Thresh slider, these areas will be preserved. The value of the slider is a percentage, but shown as a decimal, so 0.01 (the default) is 1%.