RayCursor

Abstract

Figure 1: Illustration of manual RayCursor: a) the user controls a cursor along the ray using relative displacements of their thumb on the controller's touchpad; b) the target closest to the cursor is highlighted. Illustration of semi-auto RayCursor: c) by default, it works like Raycasting. The cursor (in black) is positioned at the intersection with a target; d) the target remains selected if the cursor moves out of the target, until it is closer to another target; e) the user can manually move the cursor using the controller's touchpad, to select another target (the cursor turns red to indicate manual mode); f) if the user does not touch the touchpad for 1s, the cursor returns to its behaviour described in c). ABSTRACTRaycasting is the most common target pointing technique in virtual reality environments. However, performance on small and distant targets is impacted by the accuracy of the pointing device and the user's motor skills. Current pointing facilitation techniques are currently only applied in the context of the virtual hand, i.e. for targets within reach. We propose enhancements to Raycasting: filtering the ray, and adding a controllable cursor on the ray to select the nearest target. We describe a series of studies for the design of the visual feedforward, filtering technique, as well as a comparative study between different 3D pointing techniques.Our results show that highlighting the nearest target is one of the most efficient visual feedforward technique. We also show that filtering the ray reduces error rate in a drastic way. Finally we show the benefits of RayCursor compared to Raycasting and another technique from the literature.

How Can I Grab That?

“…The selection task consists of two phases, which are visible in Figure 2. The task was developed to allow for a simple variation of the used independent variables and is based on tasks used in similar studies (e. g. [6]). A red sphere, an arm-length away from the user, had to be selected first to start the time measurement and to spawn an arrangement of one or multiple spheres where the target sphere was colored green.…”

Outline Pursuits: Gaze-assisted Selection of Occluded Objects in Virtual Reality

“…Use of a volume for selection requires disambiguation from among initially selected objects, for which a range of techniques exist. Many of these techniques require an additional manual step for final selection [3,11,19], while others apply heuristics or contextual information for implicit disambiguation [8,11,33,37]. In our technique, disambiguation is explicit but based on smooth pursuit eye movement instead of a second pointing step.…”

“…Pointing is a fundamental task for selection of objects in virtual reality (VR). Users are commonly supported with manual controllers and raycasting [2,3,7] but hands-free alternatives are available based on head or gaze tracking [20,30]. Irrespective of modality, occlusion presents a principal problem for selection in VR environments.…”

Modeling and Reducing Spatial Jitter caused by Asynchronous Input and Output Rates

“…Jitter is known to affect human performance [27] and sub jective preferences [24], and is usually assumed to originate from imprecise input sensing, scaling factors introduced by interaction techniques, and human limbs tremor [27,10]. For instance, interaction techniques like Raycasting can introduce large scaling factors that amplify input device noise and hu man tremor [6]. 'Next-point prediction,' used to compensate interactive latency on a software level, can also introduce jitter by exacerbating minute imprecision and quantization effects in mouse or finger input [24] through extrapolation.…”