Photorealism and Kinematics for Web-based CAD data

As cloud technology gains traction as a platform in the architecture, engineering, and construction (AEC) sector, so does the adoption of Web3D technologies for the visualisation of massive 3D models. However, the interaction with highly complex CAD models typical of these sectors is still critical. Various efforts are found in the literature to create suitable transmission formats that do not require users to wait long periods for massive scenes to load and to define standards for enhancing such data with interaction. However, most of the existing frameworks are either domain-specific or too general, which results in increased data preparation times and additional needs for processing at the application level. This paper describes a novel system for CAD (Computer-Aided Design) data interaction built on Web3D technologies. First, we discuss the approach to prepare CAD models for visualisation: importation of data, the definition of mechanical behaviours, and physically-based rendering (PBR) properties. Next, we describe how to export CAD models as an X3D scene with federated glTF nodes to increase performance and overall client interactivity. We continue with a discussion on how the Denavit-Hartenberg (DH) parameters enable the visualisation of mechanical motion characteristics directly from the design and enhance user interaction. Finally, we draw some conclusions, and we summarise lessons learned from this industry-based software engineering experience. We also identify several future research directions in this area.