Manufacturing | Formwork - Automated BIM Validation with Rhino.Inside.Revit
To ensure the reliability of our formwork solvers, we engineered a diagnostic engine that validates geometric integrity. By running asynchronous ray-shooting and topology tests via a headless Rhino backend, the tool identifies and isolates microscopic modelling errors that native Revit tools miss.
- Client
- MFE Formwork
- Timeline
- 2022
- Service
- Custom Applications→
The Engineering Challenge
Automated formwork solvers rely on a "Perfect World" assumption: that the architectural model is geometrically watertight. However, real-world Revit models are rarely perfect. Minute gaps (0.5mm), duplicate elements, and non-manifold edges are invisible to the naked eye but catastrophic for Boolean algorithms.
If a user ran the Deck or Wall solvers on dirty geometry, the process would fail silently or produce invalid results. MFE needed a "Sanitizer" - a fail-fast diagnostic tool that could mathematically verify the model's integrity and guide users to fix errors before they became expensive problems.
The Solution Architecture
We engineered the Model Error Checker, a WPF-based diagnostic application that acts as the "Gatekeeper" for the automation suite. It uses the same headless Rhino.Inside backend to perform rigorous geometric analysis on the Revit model.
The Test Framework Pattern
We structured the tool like a Unit Test Runner.
- Asynchronous Analysis: When the user clicks "Analyze," the tool spawns 10 parallel tests. These range from simple topology checks (Duplicate Elements) to computationally intensive algorithms (Small Gap Detection).
- Ray-Shooting Algorithms: To find microscopic gaps between walls and slabs, we implemented a Ray-Shooting Algorithm in RhinoCommon. It fires vectors from face surfaces to detect near-miss intersections that indicate sloppy modelling.
- Topology Validation: The tool validates the "Shell Model" merge logic, identifying non-manifold edges (where >2 faces meet) and unmergeable tangent edges that would break the formwork solvers.
Interactive Diagnostics
A list of errors is useless if the user can't find them. We built a bidirectional navigation system.
- Visual Isolation: Clicking an error in the UI immediately triggers a command in Revit to Isolate the specific elements with a Section Box, zooming the user directly to the problem area.
- Rhino Visualization: The embedded viewport highlights the specific edge or face in red, using a custom Display Pipeline, so the user understands exactly which geometry failed, not just which element.
State-Aware Analysis
The tool monitors the Revit document in real-time. If a user modifies an element to fix a bug, the tool detects the change and flags the results as "Stale," prompting a re-analysis. This creates a tight feedback loop: Analyze → Fix → Verify.
The Result
The tool reduced a multi-day engineering task to a 60-second background process.
- Massive Scale: It handles over 650 component types, automatically selecting the correct panel for walls, beams, and openings.
- Intelligent Output: The solver output is not just geometry; it is a valid engineering solution that respects wall-tie alignment, balance panel minimums, and structural prop positions.
- Zero Setup: Unlike manual drafting, the user simply clicks "Generate Formwork". The tool handles all surface extraction, alignment, and packing automatically.
- 10
- Asynchronous Geometric Tests
- 0.1mm
- Gap Detection Tolerance
- 100%
- Solver Pre-Check Reliability
- <1s
- Navigation to Error Location