The Point Cloud to Swatch relationship can be thought of as a surface point analysis tool. It is an even more specialized cloud to surface face relationship that also takes a reference point on that surface as an input.
Selection
When a swatch point is built, selection is performed in a couple of separate steps:
Select Input Cloud. The first step is to select the input cloud, which is used as the reference for the point extraction process.
Select Surface Faces. A surface face selection is needed when selecting existing points (you can just press Enter to build points on a surface face directly) The surface selection is required to orient the extraction process.
Select Existing Reference Points. Select the existing points on the selected surface that you intend to use a reference.
Create Reference Points - Click On Surface Faces. If nominal reference points are not available this prompt allows you to select points directly on the CAD to build swatch points.
The Filter process
Swatch Points monitor the relative position of a point cloud and the the reference point on the CAD. They dynamically extract and build a mini proximity cloud based on specific settings found in the Swatch Sample Extents dialog.
These proximity settings define a cylindrical zone on the surface of the CAD model centered at the reference point and using the local normal from the CAD face to define the cylinder axis.
Maximum Radial Offset. Defines the radius of the cylindrical filter zone
Minimum / Maximum Axial offset. These controls define how far cloud points can be from the surface in either direction and still be detected.
The resulting computed point uses the average distance values in the cloud swatch to compute the point offset. This ensures that the offset is correct even on curved surfaces.
Use the Cardinal Point Location button to define the output collection and group for the computed point.