Trace as-built lines over a point cloud

What you will make

An as-built floor plan: the walls of a scanned building drawn as lines and polylines exactly on the scan's points.

Attach the cloud

1. Set the drawing's units first if it has none (the Units box in Properties, or UNITS): CadCraft converts the cloud from its own units to the drawing's.
2. Type POINTCLOUDATTACH (or PCATTACH) and press ReturnEnter. Pick a .las, .laz, .xyz or .pts file. You can also open the file with Open, drop it on the page, or send it from the BIM viewer's Trace in CadCraft.
3. Lower-left corner of the cloud: press ReturnEnter to keep the file's own coordinates (a scan registered to the project lines up with the drawing), or click where its lower-left corner goes.
4. The command line says how many points show. The view zooms to the cloud; it lies under the linework, every point seen from above.

Cut a plan slice and trace

1. Type POINTCLOUD (or PC), then S for Slice. Only a thin band 1.2 m above the cloud's lowest point shows: walls, door openings and columns read like a floor plan.
2. H sets the height of the cut, T its thickness (in drawing units). ReturnEnter ends the command.
3. Turn on object snap (F3F3) with Node among the snaps. Draw with LINE or PLINE: the cursor snaps to the slice's points, labelled "Point cloud". The drawing's own endpoints, midpoints and centers win over the cloud, so closing a polyline lands on its first point.
4. Change the cut height to trace another level, then turn the slice off (S again) to see the whole cloud.

More options

In POINTCLOUD: C colors the points by the file's colors, height, intensity, LiDAR class or one color; SI sets the point size; V hides or shows the cloud; Z zooms to it; D detaches it.

The 3D tab shows the cloud too, its lowest point on the ground, with the same slice.