Projection-based visualization of tangential deformation of nonrigid surface by deformation estimation using infrared texture

In this paper, we propose a projection-based mixed reality system that visualizes the tangential deformation of a nonrigid surface by superimposing graphics directly onto the surface by projected imagery. The superimposed graphics are deformed according to the surface deformation. To achieve this goal, we develop a computer vision technique that estimates the tangential deformation by measuring the frame-by-frame movement of an infrared (IR) texture on the surface. IR ink, which can be captured by an IR camera under IR light, but is invisible to the human eye, is used to provide the surface texture. Consequently, the texture does not degrade the image quality of the augmented graphics. The proposed technique measures individually the surface motion between two successive frames. Therefore, it does not suffer from occlusions caused by interactions and allows touching, pushing, pulling, and pinching, etc. The moving least squares technique interpolates the measured result to estimate denser surface deformation. The proposed method relies only on the apparent motion measurement; thus, it is not limited to a specific deformation characteristic, but is flexible for multiple deformable materials, such as viscoelastic and elastic materials. Experiments confirm that, with the proposed method, we can visualize the surface deformation of various materials by projected illumination, even when the user’s hand occludes the surface from the camera.Punpongsanon, P., Iwai, D. & Sato, K. Projection-based visualization of tangential deformation of nonrigid surface by deformation estimation using infrared texture. Virtual Reality 19, 45–56 (2015). https://doi.org/10.1007/s10055-014-0256-y.This is a post-peer-review, pre-copyedit version of an article published in Virtual Reality. The final authenticated version is available online at: https://doi.org/10.1007/s10055-014-0256-y

Topology Optimization with Text-Guided Stylization

We propose an approach for the generation of topology-optimized structures with text-guided appearance stylization. This methodology aims to enrich the concurrent design of a structure's physical functionality and aesthetic appearance. Users can effortlessly input descriptive text to govern the style of the structure. Our system employs a hash-encoded neural network as the implicit structure representation backbone, which serves as the foundation for the co-optimization of structural mechanical performance, style, and connectivity, to ensure full-color, high-quality 3D-printable solutions. We substantiate the effectiveness of our system through extensive comparisons, demonstrations, and a 3D printing test

Focal Surface Projection: Extending Projector Depth-of-Field Using a Phase-Only Spatial Light Modulator

We present a focal surface projection to solve the narrow depth-of-field problem in projection mapping applications. We apply a phase-only spatial light modulator to realize nonuniform focusing distances, whereby the projected contents appear focused on a surface with considerable depth variations. The feasibility of the proposed technique was validated through a physical experiment

Superimposing Dynamic Range

Replacing a uniform illumination by a high-frequent illumination enhances the contrast of observed and captured images. We modulate spatially and temporally multiplexed (projected) light with reflective or transmissive matter to achieve high dynamic range visualizations of radiological images on printed paper or ePaper, and to boost the optical contrast of images viewed or imaged with light microscopes

Speeded-Up Focus Control of Electrically Tunable Lens by Sparse Optimization

Electrically tunable lenses (ETL), also known as liquid lenses, can be focused at various distances by changing the electric signal applied on the lens. ETLs require no mechanical structures, and therefore, provide a more compact and inexpensive focus control than conventional computerized translation stages. They have been exploited in a wide range of imaging and display systems and enabled novel applications for the last several years. However, the optical fluid in the ETL is rippled after the actuation, which physically limits the response time and significantly hampers the applicability range. To alleviate this problem, we apply a sparse optimization framework that optimizes the temporal pattern of the electrical signal input to the ETL. In verification experiments, the proposed method accelerated the convergence of the focal length to the target patterns. In particular, it converged the optical power to the target at twice the speed of the simply determined input signal, and increased the quality of the captured image during multi-focal imaging

Ground Navigation in 3D Scenes using Simple Body Motions

ICAT－EGVE 2014 (the 24th International Conference on Artificial Reality and Telexistence and the 19th Eurographics Symposium on Virtual Environments