Kei Iwasaki

An Efficient Method for Rendering Underwater Optical Effects Using Graphics Hardware

The display of realistic natural scenes is one of the most important research areas in computer graphics. Therendering of water is one of the essential components. This paper proposes an efficient method for renderingimages of scenes within water. For underwater scenery, the shafts of light and caustics are attractive and importantelements. However, computing these effects is difficult and time‐consuming since light refracts when passingthrough waves. To address the problem, our method makes use of graphics hardware to accelerate the computation.Our method displays the shafts of light by accumulating the intensities of streaks of light by using hardware colorblending functions. Making use of a Z‐buffer and a stencil buffer accelerates the rendering of caustics. Moreover,by using a shadow mapping technique, our method can display shafts of light and caustics taking account ofshadows due to objects.

A Fast Rendering Method for Refractive and Reflective Caustics Due to Water Surfaces

In order to synthesize realistic images of scenes that include water surfaces, the rendering of optical effectscaused by waves on the water surface, such as caustics and reflection, is necessary. However, rendering causticsis quite complex and time‐consuming. In recent years, the performance of graphics hardware has made significantprogress. This fact encourages researchers to study the acceleration of realistic image synthesis. We present herea method for the fast rendering of refractive and reflective caustics due to water surfaces. In the proposed method,an object is expressed by a set of texture mapped slices. We calculate the intensities of the caustics on the objectby using the slices and store the intensities as textures. This makes it possible to render caustics at interactive rateby using graphics hardware. Moreover, we render objects that are reflected and refracted due to the water surfaceby using reflection/refraction mapping of these slices.

Long noncoding RNA UPAT promotes colon tumorigenesis by inhibiting degradation of UHRF1

Significance Many long noncoding RNAs (lncRNAs) play critical roles in tumor development. Here we show that an lncRNA termed UPAT [ubiquitin-like plant homeodomain and really interesting new gene finger domain-containing protein 1 (UHRF1) Protein Associated Transcript] is required for the tumorigenicity of colorectal cancer cells. UPAT interacts with and stabilizes the epigenetic factor UHRF1 by interfering with its ubiquitination and degradation. Furthermore, the UHRF1–UPAT axis up-regulates Stearoyl-CoA desaturase 1 and Sprouty 4, which are required for the survival of colon tumor cells. Our study provides evidence for an lncRNA that regulates protein ubiquitination and degradation and thereby plays a critical role in the survival and tumorigenicity of tumor cells. Our results suggest that UPAT and UHRF1 may be promising molecular targets for the therapy of colon cancer. Many long noncoding RNAs (lncRNAs) are reported to be dysregulated in human cancers and play critical roles in tumor development and progression. Furthermore, it has been reported that many lncRNAs regulate gene expression by recruiting chromatin remodeling complexes to specific genomic loci or by controlling transcriptional or posttranscriptional processes. Here we show that an lncRNA termed UPAT [ubiquitin-like plant homeodomain (PHD) and really interesting new gene (RING) finger domain-containing protein 1 (UHRF1) Protein Associated Transcript] is required for the survival and tumorigenicity of colorectal cancer cells. UPAT interacts with and stabilizes the epigenetic factor UHRF1 by interfering with its β-transducin repeat-containing protein (TrCP)–mediated ubiquitination. Furthermore, we demonstrate that UHRF1 up-regulates Stearoyl-CoA desaturase 1 and Sprouty 4, which are required for the survival of colon tumor cells. Our study provides evidence for an lncRNA that regulates protein ubiquitination and degradation and thereby plays a critical role in the survival and tumorigenicity of tumor cells. Our results suggest that UPAT and UHRF1 may be promising molecular targets for the therapy of colon cancer.

Efficient rendering of optical effects within water using graphics hardware

The display of realistic natural scenes is one of the most important research areas in computer graphics. The rendering of water is one of the essential components. The paper proposes an efficient method for rendering images of scenes within water. For underwater scenery, the shafts of light and caustics are attractive and important elements. However, computing these effects is difficult and time-consuming, since light refracts when passing through waves. To address the problem, our method makes use of graphics hardware to accelerate the computation. Our method displays the shafts of light by accumulating the intensities of streaks of light by using hardware color blending functions. The rendering of caustics is accelerated by making use of a Z-buffer and a stencil buffer. Moreover, by using a shadow mapping technique, our method can display shafts of light and caustics, taking account of shadows due to objects.

Real-time rendering of soap bubbles taking into account light interference

In the field of computer graphics, simulation of physical phenomena is of great interest. We focus on the optical effects of soap bubbles. Soap bubbles have fascinating coloration and interesting physical properties. Therefore they are useful for the entertainment such as movies and games. Soap bubbles change their shapes by surface tension and external forces, and therefore their surface thickness also changes. Since the thickness of the soap bubble is several hundred nanometers, interference of the light occurs. This paper proposes a fast rendering method for the soap bubbles taking into account light interference and dynamics. In our method, the reflectivities of the thin film that is the cause of the light interference are calculated in advance and stored as textures. This makes it possible to render the de-formable soap bubbles in real-time

A volume rendering approach for sea surfaces taking into account second order scattering using scattering maps

We present a fast volume rendering technique for sea surfaces taking into account second order scattering using graphics hardware. To generate realistic images of the sea surfaces, accurate simulation of light transport within water is necessary. In particular, multiple scattering due to particles in the water plays an important role in creating realistic images. In this paper, we introduce the concept of a scattering map for efficient computation of light scattering within water volume. In order to calculate second order scattering of light, we slice the water volume into virtual horizontal planes and calculate the radiance from second order scattering of light at sampling points on these planes. The radiance on the virtual planes can be treated as a texture map. This makes it possible to accelerate the computation using graphics hardware.