How to Work with Point Clouds in BricsCAD BIM

Quick answer: The point cloud Scan to BIM semi-automatic workflow has four steps: detecting floors with POINTCLOUDDETECTFLOORS (assigning a floor number to each selected point), detecting rooms with POINTCLOUDDETECTROOMS (assigning a room number to each point), creating room solids with POINTCLOUDFITROOMS based on those rooms, and creating BIM components with BIMINVERTSPACES, which builds walls between selected solids, wall openings, outer walls, and slabs. See the separate Point cloud Scan to BIM workflow article for more depth on this process.

POINTCLOUDFITPLANAR

Semi-automatically creates 3D geometry from a point cloud scan, a planar surface or solid, after selecting one point. Since scanned points are never exactly coplanar, a threshold value (a property of the point cloud entity) controls how close counts as flat. This works in the Bubble viewer too.

From the Bubble view: with the viewer open before launching the command, BricsCAD expects your selection there; the cursor previews the plane’s direction, and clicking shows a preview in both bubble and model views (press Ctrl to switch between two shape representations).

1. Double-click a green point cloud bubble to open the Bubble viewer.
2. Type POINTCLOUDFITPLANAR.
3. Select the desired wall.
4. Press A to accept the selection, optionally selecting more walls.
5. Close the Bubble viewer; the surfaces create, editable into closed spaces with LCONNECT (the same command covered on this hub’s BIM linear solids page) or other connecting tools.

From model space: usable when the Bubble viewer isn’t open; BricsCAD asks you to select a point in model space directly. It takes longer, since it searches multiple scan positions, but has two advantages: it can build larger surfaces combining partial visibility across several scans, and it can detect wall or slab thickness by considering the opposite surface too.

1. Type POINTCLOUDFITPLANAR.
2. Select a wall where you want to create a plane or solid.
3. You’re prompted to Accept, Decline, or switch Mode: press A to create, D to decline, or M/Ctrl repeatedly to cycle modes. Contour mode creates the best-fitting plane; Rectangular mode creates a rectangular plane around the region of planar points; Solid mode creates a solid from two parallel point cloud planes (useful for automatically creating solid walls when the point cloud covers multiple rooms).
4. Press A to create the wall.

These solids form a base for a more complex BIM model; complete the building with modeling commands, then add BIM data with Bimify, Automatch, and Propagate to quickly turn a point cloud into a full BIM building. Turning on the Pointcloud Nearest Point entity snap (PCNEAREST, or the 3DOSMODE system variable) significantly improves your ability to select relevant points.

POINTCLOUDPROJECTSECTION

Automatically generates a raster image, with optional contour lines, from a defined section box, easily turned into a detailed 2D drawing. It detects walls from the volume section of a point cloud based on various wall-detection options; create volume sections with BIMSECTION, the same command covered on this hub’s BIM sections page, to generate 2D lines for a floor plan or vertical section. This runs as a background process, with multiple sections processed in a queue, letting you run it at full resolution across every section.

A raster image also generates alongside for context. This is especially useful when recreating the existing building isn’t necessary, using the background image to verify the created 2D geometry, or, with high-quality scans, as graphical material in its own right, a background image for a BIM model in a renovation project involving modern interventions in a historical building, for example.

Creating a raster image:

1. Type POINTCLOUDPROJECTSECTION; the Command Context panel opens.
2. Customize the options and turn off Detect walls.
3. Click Apply to generate the raster image.

Making horizontal sections:

1. Type POINTCLOUDPROJECTSECTION; the Command Context panel opens.
2. Turn on Detect walls to generate green detected wall lines.
3. Click Apply (trace any missing lines manually over the background image if needed).

Making vertical sections: create a vertical section box at the location you want the projection, making sure the blue round arrow points toward the side you want it projected from.

Frequently Asked Questions

What are the two advantages of using POINTCLOUDFITPLANAR in model space instead of the Bubble viewer? It can build larger surfaces from partial visibility across multiple scans, and it can detect wall or slab thickness by considering the opposite surface.

Which entity snap setting makes selecting relevant point cloud points easier? Pointcloud Nearest Point, toggled via PCNEAREST or the 3DOSMODE system variable.

What does Solid mode do differently from Contour or Rectangular mode in POINTCLOUDFITPLANAR? It creates a solid from two parallel point cloud planes, useful for automatically generating solid walls when the point cloud spans multiple rooms.

Can POINTCLOUDPROJECTSECTION process more than one section at a time? Yes, it runs as a background process with multiple sections queued, allowing full-resolution processing across all of them.