Automated and Adaptive Geometry Preparation for AR/VR-Applications

Abstract

Product visualization in AR/VR applications requires a largely manual process of data preparation. Previous publications focus on error-free triangulation or transformation of product structure data and display attributes for AR/VR applications. This paper focuses on the preparation of the required geometry data. In this context, a significant reduction in effort can be achieved through automation. The steps of geometry preparation are identified and examined concerning their automation potential. In addition, possible couplings of sub-steps are discussed. Based on these explanations, a structure for the geometry preparation process is proposed. With this structured preparation process, it becomes possible to consider the available computing power of the target platform during the geometry preparation. The number of objects to be rendered, the tessellation quality, and the level of detail can be controlled by the automated choice of transformation parameters. Through this approach, tedious preparation tasks and iterative performance optimization can be avoided in the future, which also simplifies the integration of AR/VR applications into product development and use. A software tool is presented in which partial steps of the automatic preparation are already implemented. After an analysis of the product structure of a CAD file, the transformation is executed for each component. Functions implemented so far allow, for example, the selection of assemblies and parts based on filter options, the transformation of geometries in batch mode, the removal of certain details, and the creation of UV maps. Flexibility, transformation quality, and timesavings are described and discussed.

Optimised Models for Ar/Vr by Using Geometric Complexity Metrics to Control Tessellation

“…In addition to the prediction models in 4.1, models for the tessellation parameter settings of 1 mm/30° and 1 mm/50° are created. The prediction models are implemented in the developed geometry preparation tool GeoPrep, see (Dammann et al, 2022b). The tool is able to collect the complexity metrics for each CAD geometry from a STEP file.…”

“…The CAD data (analytical geometry and product structure) needs to be transformed to AR/VR data (polygon meshes, product structure, metadata) in a geometry preparation process (Dammann et al, 2022b;Santos et al, 2021;Graf et al, 2002;Salonen et al, 2009). The main task in this process is the discretisation of the analytical geometry, which is called tessellation (Dammann et al, 2022b). Tessellation algorithms offer parameters to control the accuracy of the discretisation, for example linear deflection and angular deflection from the parametric geometry.…”

“…In theory the tessellation parameters can be derived from the complexity and importance of the geometry. As product models often contain thousands of components, all geometries are tessellated with the same parameters due to a lack of automated parameter choice (Lorenz et al, 2016;Dammann et al, 2022b). This approach often results in models with too many polygons (e.g.…”

“…However, product geometry in engineering is described analytically in CAD systems. The CAD data (analytical geometry and product structure) needs to be transformed to AR/VR data (polygon meshes, product structure, metadata) in a geometry preparation process (Dammann et al, 2022b;Santos et al, 2021;Graf et al, 2002;Salonen et al, 2009). The main task in this process is the discretisation of the analytical geometry, which is called tessellation (Dammann et al, 2022b).…”

Extended Reality Application Framework for a Digital-Twin-Based Smart Crane

“…The development of XR technologies has brought many research directions, including industrial model preparation, information integration, data visualization, and XR application development. Dammann et al [31] provided a structure for the geometry preparation automation process, which simplified the integration of XR applications into product development. Bellalouna [32] proposed a digital transformation of engineering processes using VR technology.…”