Natural Finger Interaction for CAD Assembly Modeling

Abstract

In current CAD software the process of assembly modeling is hindered by a large number of separate rotation and translation actions necessary, especially in case of larger assemblies. Additionally matching faces, edges or points must be selected by clicking to define the appropriate constraint. In contrast to that, the process of assembling two normal sized physical parts in the real world seems to be rather simple. That is because we know how to grasp and move objects with our hands intuitively from our everyday experience. The idea behind this contribution is to enable the product developer to assemble CAD parts in a virtual environment through natural finger interaction like in reality. Therefore we present an overall method that combines the natural finger interaction with virtual objects and the insertion of constraints between rotationally symmetric CAD parts. The developed algorithms identify matching surfaces on the basis of the geometry as well as position and orientation of the parts in 3D space. This paper highlights the method to use a combination of real-time physics simulation and a heuristic approach to achieve an intuitive interaction interface. Additionally, we describe the detection algorithms developed to find assembly relationships between rotationally symmetric CAD parts without prior constraint definition. We also present a prototype system to demonstrate the functionality of the overall method. Furthermore, challenges for future research, such as extending the functionality of the detection algorithms on additional part types, like non-rotationally symmetric shapes, are discussed.

Comparative evaluation of WIMP and immersive natural finger interaction: a user study on CAD assembly modeling

“…Implementing the detection algorithms into the mouse and keyboard operated desktop environment would not be reasonable. Again, the small p values and the high effect sizes for the evaluable samples indicate small probabilities of error and strong effects (Cohen 1988).…”

“…These are approximate values which may vary depending on the characteristics of the task (e.g., object size, distance and rotation angle). The very small p values and the high effect sizes (> 0.8) for the evaluable samples indicate small probabilities of error and strong effects (Cohen 1988). Outliers in the virtual environment can occur if finger tracking problems appear or the user inadvertently pushes objects out of their current range (e.g., toward the floor plane).…”

Linking a game-engine with CAD-software to create a flexible platform for researching extended reality interfaces for the industrial design process

“…However, extended reality (XR) interfaces, which are all interfaces using virtual, mixed, or augmented reality, can extend the functionalities of CAD software. Advantages of XR-CAD interfaces can range from easier access for inexperienced users, faster interactions, improved size perception to simply a more compelling experience [1][2][3].…”

“…They created a custom framework combining Leap Motion SDK, Oculus SDK, Nvidia PhysiX, Open Scene Graph, and Ansys SpaceClaim to prototype and evaluate their developed interactions [5]. First assembly modeling was implemented [2] and recently design sketch creation was explored [6].…”

A Review of Requirements and Approaches for Realistic Visual Perception in Virtual Reality

“…(Esser et al, 2016) Interaction with components in VR enables intuitive handling, e.g. for assembling processes (Fechter and Wartzack, 2017). Thus, the designer can get intuitive access to various mechanical components, which is particularly advantageous for design modifications.…”