“Of all the apps we have, RealityCapture is as used as Revit,” reveals Mark Cichy, Principal & Director of Design Technology at HOK. “We use it everyday. That's how important it is to this process.”
RealityCapture models are validated in Revit to ensure their scale works in 3D space, or optimized in Houdini for web and VR visualization platforms. They’re also further refined with Twinmotion, which is used to do everything from exploring circulation paths and entry corridor sequences to adding extra detail with the help of a library of realistic trees, plants, and people.
Once ready, the team moved on to Unreal Engine to prepare dynamic client presentations that ensured stakeholders could see the impact of design choices and iterations in real time. Unreal Engine development efforts also allow HOK to visualize every state of the building as it progresses through different stages of the decade-long project timeline.
Every stone, every step
In order to generate a virtual mock-up of Centre Block, both fixed and mobile heritage assets throughout the building first need to be scanned. So far, this has resulted in 100TBs of point cloud data and a 70TB mesh.
“We have many conservationists working around the clock to document the state and properties of each heritage asset,” says Cichy. “Parts of Centre Block are literally being dismantled stone by stone in order to achieve this. Each stone is captured via a sophisticated point cloud scanning process, then digitally reassembled to record the original state for future reference.”
To capture roof geometry, terrestrial scanning wasn’t enough. Because parts of the roof were not easily accessible, a local drone operator was hired to fly around and capture high-quality photos and video of the area, allowing the team to generate detailed photogrammetric meshes from exceptionally high-resolution orthographic photography.
As the data is collected, it is fed into Unreal Engine, which is used to generate multiple dynamic Level of Detail models (LODs) and visualized using virtual reality walkthroughs. Users can jump to several locations within these models, setting perspective height so they can preview the spaces as if they were there themselves. Several of HOK’s early results have been shared with the client via a variety of tethered (HTC Vive, Oculus Rift, Varjo XR3) and untethered (Oculus Quest and Google Cardboard) VR devices.
“Places like the House of Commons Chamber were created using the photogrammetric mesh,” adds Cichy. “This allows VR users to preview the exact scale, geometry and textures as one would experience within the real House of Commons.”
Real-time design
So far, the HOK team have used Unreal Engine throughout the entire schematic design process for the project, which includes the Centre Block building receiving a host of upgrades including seismic base isolation pads, high-performance insulation, and mechanical and electrical equipment such as enhanced audio devices in the Senate and House of Commons.
“From day one, it’s helped us to perform content audits internally, and convey our proposed design intent in a far more engaging way,” Cichy says. “We do not possess another tool that can handle multi-terabyte data streams as well as Unreal Engine—regardless of whether these are represented in real time or simply harvested to coordinate various data sources.”
Their interactive walkthroughs have already brought huge benefits to the Centre Block project, as clients could make decisions and comment on what they did or didn’t like about the project’s renovation design strategies directly in virtual reality, before spending billions on a decision that could make permanent changes to a site of historic significance.