Meshmixer's Bridge tool is similar to that found in other mesh repair tools. The goal of a Bridge is to cross a gap/hole in the mesh. This allows large, complex holes to be subdivided into smaller holes which can be filled more easily. Our strategy is to first construct a minimal triangulation that crosses the hole, and then use remeshing to produce a high-quality triangulation.
To use the Bridge tool, you must select two separate regions that contain mesh boundaries. Only the boundary edges will be bridged, the actual selected triangles are not modified. See below for an example.
The property panel for Bridge is shown to the right. This panel currently only has one setting, Refine, which controls the number of remeshing iterations applied to the bridge mesh. See the Remesh too for more details. If you set the Refine slider to 0, remeshing is disabled and you will get a minimal-triangulation bridge.
The image below shows an example usage of the Bridge tool. Note that we do not require the same number of boundary edges on either side of the gap. In fact the Bridge tool easily handles large differences in the number of boundary edges on either side.
One thing to note is that currently the bridge surface is not constrained to be tangent-continuous with the border triangles. As a result, it tends to be "flattened" relative to curved surfaces. So, if you need to use Bridge to subdivide large holes, we recommend creating the bridges in flat areas. Even if the holes are slightly more complex, the Erase/Fill tool is capable of providing (approximate) tangent continuity.