3D Object Rotation Using Virtual Trackball with Fixed Reference Axis

Among the 3D interaction techniques designed in the last decades to examine virtual objects using the mouse, virtual trackballs are especially suitable for overall examination of 3D objects. This experimental study focuses on a specific type among the various virtual trackball techniques: Two-Axis Valuator (TAV) with fixed axis. The classical TAV considers rotations around global X- and Y-axis, but for many applications, like 3D modelling, and many web-based 3D viewers, a special variation of the TAV is implemented, where horizontal displacements of the mouse are mapped to rotation around the fixed vertical axis. This technique is known as TAV with fixed up-vector (Bade, 2005) or just fixed trackball (Rybicki, 2016), and achieves transitive rotations. However, for some objects, there can be another intrinsic axis. For instance, objects like the rotor of a turbine have an intrinsic rotation axis, often horizontal (González-Toledo, 2017). In order to work with these objects, we propose to use a TAV with a generic fixed axis, which is not necessarily vertical. The hypothesis of this study is that the consistency between the object's intrinsic axis and the fixed axis in a TAV interaction will make interaction more natural, as the user's mental model will be a better fit to the interaction technique or, in other words, the level of stimulus-response compatibility will be higher.