2,203 research outputs found
Calipso: Physics-based Image and Video Editing through CAD Model Proxies
We present Calipso, an interactive method for editing images and videos in a
physically-coherent manner. Our main idea is to realize physics-based
manipulations by running a full physics simulation on proxy geometries given by
non-rigidly aligned CAD models. Running these simulations allows us to apply
new, unseen forces to move or deform selected objects, change physical
parameters such as mass or elasticity, or even add entire new objects that
interact with the rest of the underlying scene. In Calipso, the user makes
edits directly in 3D; these edits are processed by the simulation and then
transfered to the target 2D content using shape-to-image correspondences in a
photo-realistic rendering process. To align the CAD models, we introduce an
efficient CAD-to-image alignment procedure that jointly minimizes for rigid and
non-rigid alignment while preserving the high-level structure of the input
shape. Moreover, the user can choose to exploit image flow to estimate scene
motion, producing coherent physical behavior with ambient dynamics. We
demonstrate Calipso's physics-based editing on a wide range of examples
producing myriad physical behavior while preserving geometric and visual
consistency.Comment: 11 page
Video Acceleration Magnification
The ability to amplify or reduce subtle image changes over time is useful in
contexts such as video editing, medical video analysis, product quality control
and sports. In these contexts there is often large motion present which
severely distorts current video amplification methods that magnify change
linearly. In this work we propose a method to cope with large motions while
still magnifying small changes. We make the following two observations: i)
large motions are linear on the temporal scale of the small changes; ii) small
changes deviate from this linearity. We ignore linear motion and propose to
magnify acceleration. Our method is pure Eulerian and does not require any
optical flow, temporal alignment or region annotations. We link temporal
second-order derivative filtering to spatial acceleration magnification. We
apply our method to moving objects where we show motion magnification and color
magnification. We provide quantitative as well as qualitative evidence for our
method while comparing to the state-of-the-art.Comment: Accepted paper at CVPR 2017. Project webpage:
http://acceleration-magnification.github.io
Seamful interweaving: heterogeneity in the theory and design of interactive systems
Design experience and theoretical discussion suggest that a narrow design focus on one tool or medium as primary may clash with the way that everyday activity involves the interweaving and combination of many heterogeneous media. Interaction may become seamless and unproblematic, even if the differences, boundaries and 'seams' in media are objectively perceivable. People accommodate and take advantage of seams and heterogeneity, in and through the process of interaction. We use an experiment with a mixed reality system to ground and detail our discussion of seamful design, which takes account of this process, and theory that reflects and informs such design. We critique the 'disappearance' mentioned by Weiser as a goal for ubicomp, and Dourish's 'embodied interaction' approach to HCI, suggesting that these design ideals may be unachievable or incomplete because they underemphasise the interdependence of 'invisible' non-rationalising interaction and focused rationalising interaction within ongoing activity
Animating the Real: Illusions, Musicality and the Live Dancing Body
Animation film frequently uses dance and choreography as part of explicit scenes to help assist with and compliment the narrative. Although animators frequently acknowledge relationships between dance and animation, scarcely any scholarly work considers how animated film principles are used and applied within live dance performances. Additionally, although many scholars discuss the relationship between live dance and music and similarly animation and music, rarely has the collision of all three been scrutinized. In this article, I draw upon principles from animation film and choreomusical scholarship to show a complex relationship between the real and the pretend in a solo street dance performance. Based on detailed movement analysis of a short solo dance performance by Isaac "Turbo" Baptiste, I discuss the ways that moving image can influence live dancing bodies and create endless possibilities for choreomusical play
Liquid surface tracking with error compensation
Our work concerns the combination of an Eulerian liquid simulation with a high-resolution surface tracker (e.g. the level set method or a Lagrangian triangle mesh). The naive application of a high-resolution surface tracker to a low-resolution velocity field can produce many visually disturbing physical and topological artifacts that limit their use in practice. We address these problems by defining an error function which compares the current state of the surface tracker to the set of physically valid surface states. By reducing this error with a gradient descent technique, we introduce a novel physics-based surface fairing method. Similarly, by treating this error function as a potential energy, we derive a new surface correction force that mimics the vortex sheet equations. We demonstrate our results with both level set and mesh-based surface trackers
Deformation embedding for point-based elastoplastic simulation
pre-printWe present a straightforward, easy-to-implement, point-based approach for animating elastoplastic materials. The core idea of our approach is the introduction of embedded space-the least-squares best fit of the material's rest state into three dimensions. Nearest neighbor queries in the embedded space efficiently update particle neighborhoods to account for plastic flow. These queries are simpler and more efficient than remeshing strategies employed in mesh-based finite element methods.We also introduce a new estimate for the volume of a particle, allowing particle masses to vary spatially and temporally with fixed density. Our approach can handle simultaneous extreme elastic and plastic deformations. We demonstrate our approach on a variety of examples that exhibit a wide range of material behaviors
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