Point Cloud Scan to BIM Workflow in BricsCAD

Quick answer: BricsCAD’s Scan to BIM workflow turns a point cloud into a building model in four semi-automatic steps: detecting floors, detecting rooms, creating room solids, and generating BIM components (walls and slabs) between them.

Prerequisite: Normal Vector Information

This workflow only applies to point clouds with normal vector information available.

• Structured data: normals calculate automatically during pre-processing. If a point cloud was pre-processed on an older BricsCAD version before normals were calculated, run POINTCLOUDNORMALS first.
• Unstructured data: normals import if present in the source data; otherwise they aren’t calculated, and this workflow doesn’t apply.

Normal vector calculation specifically requires a point cloud processed in HSPC format, with both POINTCLOUDHSPC and POINTCLOUDNORMALS set to on (both on by default).

Step 1: Detecting Floors

1. Launch POINTCLOUDDETECTFLOORS. You’re prompted to select a point cloud entity.
2. Select the point cloud attached to your drawing. You’re asked whether to operate on the full point cloud or a selection.
3. Either click Full, or click Selection and specify a selection rectangle’s first and opposite points. You’re asked whether to create spatial elements.
4. Choose Yes to create spatial elements based on the detected floor heights.
5. A Command line message confirms when detection finishes. The detected floors are listed in the Point Cloud Manager panel under Buildings.
6. Optionally, right-click a floor in the Point Cloud Manager and choose Modify to adjust which points are assigned to it.

Step 2: Detecting Rooms

1. Launch POINTCLOUDDETECTROOMS. You’re prompted to specify a floor ID or select all.
2. Either click All to detect rooms across every listed floor, or Id to target a specific one.
3. Background processing begins, this can take several minutes depending on point cloud size, but you can keep working while it runs. A pop-up appears once it finishes, and the classified rooms are listed in the Point Cloud Manager under Buildings, each with its own ID.

From there, you can refine the result:

• Toggle a room’s visibility icon to check whether it was detected correctly.
• Right-click a room and choose Edit to adjust its contour by dragging polyline points, then Accept or Decline the change.
• Use Rename or Delete as needed.
• Select multiple rooms and choose Merge to combine them.
• Right-click a floor’s name and choose Add Room to draw a polyline defining a new room boundary manually.

Step 3: Creating Room Solids

1. Launch POINTCLOUDFITROOMS. You’re prompted to specify a building ID or select all.
2. Either click All or Id. You’re asked whether to restrict detection to perpendicular (90 degree) walls.
3. Choose Yes if the rooms have two perpendicular wall directions. Background processing begins again, potentially taking several minutes, and you can continue working while it runs. A pop-up confirms completion, and the resulting solids are assigned to an automatically generated Rooms layer.
4. Turn off the attached point cloud’s visibility to see the room solids clearly.

Optionally, use DMPUSHPULL afterward to adjust the faces of the created solids directly.

Step 4: Creating BIM Components

1. Select the layer where the BIM components should be created.
2. Launch BIMINVERTSPACES. The Invert Spaces Command Context panel opens with its settings.
3. Click Apply.

This generates walls between the room solids, plus the building’s outer shell, completing the workflow with a full 3D model based on the original point cloud.

Verifying and Editing the Result

1. Turn off the layer containing the room solids.
2. Use BIMSECTION to create a horizontal section plane that reveals the internal walls.
3. Use wall editing tools like LCONNECT or BIMEXTEND to adjust the result as needed.

Frequently Asked Questions

Does this workflow work on any point cloud? Only ones with normal vector information available. Structured data calculates this automatically during pre-processing; unstructured data needs it present in the source file already, otherwise the workflow doesn’t apply.

Can I keep working in BricsCAD while room or floor detection runs? Yes, both POINTCLOUDDETECTROOMS and POINTCLOUDFITROOMS run as background processes you can continue working through.

What happens if a room wasn’t detected correctly? Right-click it in the Point Cloud Manager and choose Edit to adjust its contour by dragging polyline points, or use Add Room to draw one manually if it was missed entirely.

Is this the only way to reach BIMINVERTSPACES from a point cloud? No, the point clouds overview page in this hub also describes reaching it via stitched POINTCLOUDFITPLANAR results, one solid per room, as an alternative to this detected-rooms workflow.