InStep Studio


Automatic RepairAutomatic Repair

Time to read: ~4 min

It is likely that this will be the first tool that users attempt to use for malformed data and likely also one that will cause most confusion or frustration.
The thing to keep in mind is that there is no one universal 'fix' that can be used to repair all possible issues. Though the tool options under the Auto Fix group attempt to cover a number of options, the problems that files may contain need to be understood rather than to rely one some 'magic' button that is supposedly meant to make up for bad decisions.
Having said that, let's take a look at the available options and some information about what the approaches attempt to do.

Method: Basic

The Basic repair tool simply applies a number of the other repair options. It attempts to:

  1. Merge Close proximity Vertices
  2. Remove Duplicate Facets
  3. Remove Invalid Facets and Edges (split and project are included)
  4. Close Holes (Smoothed Method)
  5. If holes persist, close them with the Bounded method
  6. Repair Normals

This method is identical to doing the above steps in the same order manually... which may be preferred if the result is not as expected. What is important to point out is that this tool does not allow data to be changed outside of what each tool does and so attempts to preserve as much as possible.

Method: Extended

The Extended Tool performs all the same options as for the Basic but takes it a step further by also looking into how the different items are represented and to also allow minor remeshing of sections that may have invalid shapes or similar. Beyond this, the data also performs automatic removal of sections that become invalid during the repair such as faces that get collapsed to a zero-area surface or similar. Edges that are not explicitly overlapping but become overlapping due to updated locations are also considered merged.

Though this approach may introduce some minor changes, it is still considered an approach that simply corrects existing data, unlike the following methods.

Method: Resampled

The Resampling Auto Repair method is somewhat similar to the wrap option and works by considering what is known as a signed-distance field (SDF). This function defines each location in the domain by a value that represents inside vs. outside. During the process, the data is sampled at the corners of a grid defined by the value selected (which represents the number of divisions along the bounding boxes largest dimension) and a new mesh is formed using the sampling information.

This approach will yield new surface data from the original data. It is recommended for cases where the original data contains a large number of small fractures or similar but will generally not be able to resolve large open sections.

Method: Solidify

Similar to the Resampled approach, this method uses a function value to determine where the surfaces are to be placed. What is different is how this function is determined. In this case, the value is not a direct determination of what is inside/outside but rather a continuously varying value representing proximity to surface data. It is generally slower in processing that the other methods as the function is more complicated but it will generally produce a closed surface from any shape.

With this option there is a similar value to pick for the number of Cells (along the largest coordinate). In addition, there is also a Parameter value which corresponds, in the range of 0 to 1 (exclusive) to an extension of the existing surface towards the inside or outside (with 0.5 being roughly along the average).
With this option, it is strongly recommended that a small initial value of the cell number is used to quickly get insight into what the output looks like for different parameter values before then moving to a higher detail model.

Method: Voxelize

In many ways this is a different approach altogether. This tool option uses a combination of the Solidify tool (and therefore uses the same input parameters) but rather than to try and generate a smooth surface it retains is original, bounding box based cubes. This has the result of generating data that is both aligned with the coordinate axes and consists of a blocky representation (aka 'Minecraft'-style data). The expected uses of this tool is for cases where the original data is highly aligned with the coordinate axes and only a rough representation or highly sharpened shape is desired. As with all tools, a rough preview can be useful in deciding whether this is benefit for the task at hand.


As with some other Repair options, some of the tools in this section can use a Parallel processing approach if the UseParallelForRepairs value is set to True from the Settings>Application Settings>Repair group

Option: All, Selected, Preview, Clear & Apply

The possibility exists to apply the tool's capabilities to All currently loaded data or only those selected (if there are multiple bodies). The Preview button will show what the result (for the selected bodies only) looks like before making changes. Clearing the preview resets the display data and the Apply option makes the changes permanent.