Scan to BIM & As-built drawings for church in Toronto

The client asked ORIGIN to create a model of the old church for a heritage digital preservation project. Designed in Gothic Revival style, the building was distinguished by its sophisticated details, such as ornate exteriors and complex vaulted ceilings.

As per the client’s request, the model needed to accurately reflect these intricate details, including both the sophisticated exterior and the detailed interiors. Additionally, a basic set of drawings, including floor plans and facades, was required to assist with further renovation planning of the church.

Input:

• Full point cloud of the interior and exterior;
• Photos of the interiors taken before the reconstruction began;
• Old 2D drawings.

Output:

• 3D model of both the exteriors and interiors in LOD 350;
• A basic set of drawings, including floor plans and facades.

While the vaulted ceiling was a highlight of the church and a remarkable feature that reinforced its Gothic style, it also presented an array of challenges.

After closely reviewing the point cloud, we discovered that each ceiling segment was curved in two directions. On top of that, the entire building, including the ceiling, was sagging. As a result, the elevation difference of similar elements at opposite ends of the building was more than 6 inches, exceeding the defined tolerance of 2 inches.

Solution:

These inconsistencies prevented us from streamlining and automating the modeling process as we usually do. Typically, the ORIGIN team would model one fragment and replicate it throughout the entire building, ensuring a fast and precise workflow. However, this technique couldn’t be applied in this case. Instead, each module had to be individually adjusted to match the point cloud with the required precision.

To create highly curved shapes in Revit, we used the mass forms tool by profiles, which allowed for the accurate modeling of non-linear surfaces. Meantime, to cover the beam structure above the ceiling, we avoided using masses and instead created elements with thickness and a more defined category. For this task, we chose wall creation by mass face since the software does not support the creation of ceilings by mass face. This allowed us to ensure that all elements were correctly represented within the constraints of the software.

Another challenge of the project was modeling the wooden structure supporting the roofs and ceilings. Since the shape of the vaulted ceiling directly influenced the configuration of the wooden timbers, most of them were curved and custom-cut to fit the ceiling. Each piece required individual attention due to its unique shape. Apart from that, the project faced significant challenges due to the high density of structural elements, tight spaces, and poor lighting conditions in the survey area. The inability to access certain areas with the scanner and distinguish between different elements made it difficult to capture a complete and accurate model.

Solution:

To meet the desired level of accuracy, the team meticulously modeled each timber, accounting for the complex curvatures and unique cuts to ensure the framework’s structural integrity in the final model. For areas that couldn’t be scanned, the ORIGIN team used structural logic and remnants of the point cloud, inferring data from the known layout to ensure model accuracy. Additionally, they used advanced software tools to enhance the visibility of available data, thus maximizing the information extracted from the point cloud despite the insufficient lighting. This approach allowed critical elements to be captured and accurately represented in the final 3D model.

The church interior featured various elements, including the organ, numerous statues, intricately carved altars, and wooden paneling. As per the client’s request, all intricate church interiors had to be accurately modeled, too.

Solution:

The ORIGIN team thoroughly analyzed all the elements that needed to be modeled to choose the most optimal approach for each. As a result, the following steps were taken:

• Organ: The front row of pipes was modeled individually with a high level of detail to represent each pipe accurately. The less visible rear contents of the organ were simplified by grouping them and modeling them as masses to save time while maintaining the organ’s overall appearance.
• Statues: The most similar statues possible were found in open sources, downloaded, modified to better match the real conditions, and imported into Revit as insert elements.
• Carved altars and wooden paneling: As agreed with the client, these were modeled at a mid-level of detail to accurately show the shape while avoiding tiny carved details.