Decal-Lenses: Interactive Lenses on Surfaces for Multivariate Visualization

Abstract

We present decal-lenses, a new interaction technique that extends the concept of magic lenses to augment and manage multivariate visualizations on arbitrary surfaces. Our object-space lenses follow the surface geometry and allow the user to change the point of view during data exploration while maintaining a spatial reference to positions where one or more lenses were placed. Each lens delimits specific regions of the surface where one or more attributes can be selected or combined. Similar to 2D lenses, the user interacts with our lenses in real-time, switching between different attributes within the lens context. The user can also visualize the surface data representations from the point of view of each lens by using local cameras. To place lenses on surfaces of intricate geometry, such as the human brain, we introduce the concept of support surfaces for designing interaction techniques. Support surfaces provide a way to place and interact with the lenses while avoiding holes and occluded regions during data exploration. We further extend decal-lenses to arbitrary regions using brushing and lassoing operations. We discuss the applicability of our technique and present several examples where our lenses can be useful to create a customized exploration of multivariate data on surfaces.

3De Interactive Lenses for Visualization in Virtual Environments

“…We also plan to support the use of simultaneous multiple lenses, investigating ways of easily applying and composing 3De lenses. In this sense, we are particularly inspired by Rocha et al's composite operations for decal-lenses [20]-e.g., one could brush or lasso over the surface to conceive lens-regions of arbitrary shapes.…”

“…They use a volumetric box to implicitly or explictly define a spatial selection in the flow to depict higher-resolution streamlines. Rocha et al [20] recently proposed decal-lenses to facilitate on-demand multivariate data exploration on surfaces; to the best of our knowledge, it is the only work fitting into Decal lens category. 3De lens does not fit into the previous individual classification; rather, it merges lenses of distinct categories into a single coherent entity.…”

“…Similarly to Rocha et al [20], we build two view-dependent buffers consisting of the surface data: a geometry buffer (G-buffer) and an attribute-layer buffer (AL-buffer). The G-buffer is a framebuffer object with three attachments: vertices, normals, and depth.…”

“…Another lens category, called Decal, supports selection of surface areas of interest. A recently proposed decal-lens [20] is built from the intersection of a sphere with a surface. The sphere itself does not provide the area where the lens effect takes place; rather, the lens refers to the part of the surface that lies inside the sphere.…”

GTMapLens: Interactive Lens for Geo‐Text Data Browsing on Map

“…5). An alternative approach could be implemented is a composition of multiple circular lenses over surface regions as in [RSA∗19],…”