Andujar, C.Argelaguet, F.Ming Lin and Roger Hubbold2014-01-272014-01-2720063-905673-33-91727-530Xhttps://doi.org/10.2312/EGVE/EGVE06/101-108The accommodation of conventional 2D GUIs with Virtual Environments (VEs) can greatly enhance the possibilities of many VE applications. In this paper we present a variation of the well-known ray-casting technique for fast and accurate selection of 2D widgets over a virtual window immersed into a 3D world. The main idea is to provide a new interaction mode where hand rotations are scaled down so that the ray is constrained to intersect the active virtual window. This is accomplished by changing the control-display ratio between the orientation of the user s hand and the ray used for selection. Our technique uses a curved representation of the ray providing visual feedback of the orientation of both the input device and the selection ray. The users feeling is that they control a flexible ray that gets curved as it moves over a virtual friction surface defined by the 2D window. We have implemented this technique and evaluated its effectiveness in terms of accuracy and performance. Our experiments on a four-sided CAVE indicate that the proposed technique can increase the speed and accuracy of component selection in 2D GUIs immersed into 3D worlds.Categories and Subject Descriptors (according to ACM CCS): I.3.6 [Computer Graphics]: Methodology and Techniques - Interaction Techniques