When modeling or preparing to print multiple objects in a scene, it is often critical to know whether the objects are a safe distance apart from one another. It is also often difficult to tell via inspection in a modeling package just how far apart objects are. This is where the Clearance tool comes in.
This tool attempts to find, for each vertex on one surface, the closest point on the other surface to that vertex. This will provide some estimate of how far apart the objects in the scene are from one another.
To use this tool, first select one object, then another, then click the Clearance tool.. We will call the first object you select object A, and the second one object B. The tool will take each vertex on object A and find the closest point on object B, and record the distance to this point. The Min Clearance slider is threshold distance. Vertices on object A that are closer to object B than this threshold are rendered in red. As well, the minimum vertex-to-surface distance is displayed as Min Distance in the UI.
If the Bi-Directional box is checked, we not only compute the distances from vertices on A to the surface B, but also the distances from vertices on B back to surface A. This can provide better accuracy if the number of vertices on object A is low.