Manufacturing | Suspended Ceilings - Automating Technical Section Detailing in AutoCAD

Runtime Integration with the Ceiling Solver

The tool shares its codebase with the ceiling solver and boots the solver infrastructure behind the scenes at startup, so the resolved 3D ceilings - exactly as the technician designed and specified them - are available at runtime. Sections are always cut from the current solved state: nothing is exported, re-imported, or allowed to fall out of sync. The UI reinforces the workflow - only section markers that intersect a solved ceiling appear as valid selections, and a single marker can span one or several ceilings depending on its length - so a ceiling must be designed before it can be detailed.

The Drawing Pipeline

The tool executes a five-stage generation process for every section marker:

1. Marker Detection: Scans the document for section callouts and extracts cut-line and break-line geometry.
2. View Region Projection: Projects the 2D cut line onto the 3D ceiling surfaces to define the intersection plane.
3. Component Intersection: Executes a sequence of polymorphic algorithms to calculate exact intersection points for panels, tees, perimeter trims, springs, and accessory hardware such as hanger and bracing clips - on flat and pitched ceilings alike - then instantiates component assemblies (blocks, dimensions, and leaders) from JSON-defined templates.
4. Content Bounds Calculation: Computes the aggregate bounding box of all component assemblies, determining model space allocation and grid range for sheet layout.
5. Entity Construction: The SectionDetailBuilder generates the final CAD entities, managing draw order and visual layering.

Section details compose through a four-level Composite hierarchy - detail, region, assembly, component - which the builder enumerates uniformly when constructing entities.

UX Integration

We engineered a modern WPF application embedded directly within the CAD environment.

• Material Design System: The UI utilizes a standardized design language to provide a clean, consistent experience shared by every tool we delivered for the client.
• Live Visualization: An integrated Rhino viewport renders the 3D spatial context of section markers, allowing users to verify cut locations visually before generation.
• Partial Sections and Breaklines: Markers can intersect a ceiling partially, or carry split-lines across expanses that do not warrant a full-length detail - the tool automatically draws breaklines where each intersection ends.

Configuration-Driven Flexibility

To support the client's evolving product lines, we implemented a JSON-driven template system. Assembly templates define which blocks, dimensions, and leaders appear together for any given product. This separation of concerns allows the client's engineering team to modify section appearances via JSON configuration without requiring code changes or recompilation.

Coordinate Transformation and Cropping

Converting 3D intersections to 2D drawings requires precise coordinate transformation. We built a CroppableEntityFactory to handle complex boundary clipping using polymorphic logic. Whether cutting a block, trimming a dimension line, or truncating a leader leg, the system applies geometry-specific logic to ensure clean, professional section edges.

Automated Sheet Composition

Generating the section is only half the job - the framework also composes the drawing set. Model space is partitioned into an internal grid where each cell is a 1:1-scale representation of the whitespace inside the client's sheet border. Finished details are placed by a 2D packing algorithm; when a detail cannot fit on the current sheet, the tool creates a new layout, numbers it in sequence, and continues packing - then generates the viewports that map each model-space grid onto its sheet.

Before running, users review a sheet and drawing tree showing exactly which details will land on which sheets, and can rename views and sheets - the names carry through as drawing titles and sheet names in the output.