This research presents a view-independent saliency model, which takes the effect of both color information and geometric information into account. The proposed method can simplify a mesh by dropping low-attention places while protecting the high-attention places. Multi-platform game contents are becoming a trend in the gaming field of CG in recent years. One of the problems in developing such game contents is the difference of the processing performance between the platforms. A content that runs smoothly on high processing-performance platform may not run smoothly on the lower-performance platforms. This problem can be solved by mesh simplification, which reduces the number of polygons in the mesh while preserving the overall shape, volume and boundaries as much as possible. Fewer polygons require less processing performance, and the simplified mesh can be processed smoothly even in low processing-performance platform. The proposed method simplifies a mesh in three steps. First, it takes a triangular polygonal mesh for simplification as input. Then, it calculates a view-independent hybrid saliency for each vertex of the input mesh. The hybrid saliency is evaluated from the curvature, the mesh saliency, the maximum, minimum, and average values of multiview image saliencies. Last, it simplifies the input mesh by dropping low hybrid saliency vertices. The experiments indicated that the proposed method yields a better result than existing methods.

Abstract This paper proposes a method for displaying images at the fovea of the retina taking visual acuity into account. Previous research has shown that a point light source projected onto the retina forms an ellipse, which can be computed with wavefront tracing from each point in space. We propose a novel concept using conoid tracing, with which we can acquire defocusing information several times faster than that acquired by previous methods. We also show that conoid tracing is more robust and produces higher quality results. In conoid tracing the ray is regarded as a conoid, a thin cone‐like shape with varying elliptical cross‐section. The viewing ray from the retina is traced as a conoid and evaluated at each sample location. Using the sampled and pre‐computed data for the spatial distribution of blurring, we implemented an interactive eyeglass simulator. This paper demonstrates some visualization results utilizing the interactivity of the simulator, which an eyeglass lens design company uses to evaluate the design of complex progressive lenses.

Abstract This paper describes a fast rendering algorithm for verification of spectacle lens design. Our method simulates refraction corrections of astigmatism as well as myopia or presbyopia. Refraction and defocus are the main issues in the simulation. For refraction, our proposed method uses per‐vertex basis ray tracing which warps the environment map and produces a real‐time refracted image which is subjectively as good as ray tracing. Conventional defocus simulation was previously done by distribution ray tracing and a real‐time solution was impossible. We introduce the concept of a blur field, which we use to displace every vertex according to its position. The blurring information is precomputed as a set of field values distributed to voxels which are formed by evenly subdividing the perspective projected space. The field values can be determined by tracing a wavefront from each voxel through the lens and the eye, and by evaluating the spread of light at the retina considering the best human accommodation effort. The blur field is stored as texture data and referred to by the vertex shader that displaces each vertex. With an interactive frame rate, blending the multiple rendering results produces a blurred image comparable to distribution ray tracing output.

Abstract This paper proposes a novel and general method of glare generation based on wave optics. A glare image is regarded as a result of Fraunhofer diffraction, which is equivalent to a 2D Fourier transform of the image of given apertures or obstacles. In conventional methods, the shapes of glare images are categorized according to their source apertures, such as pupils and eyelashes and their basic shapes (e.g. halos, coronas, or radial streaks) are manually generated as templates, mainly based on statistical observation. Realistic variations of these basic shapes often depend on the use of random numbers. Our proposed method computes glare images fully automatically from aperture images and can be applied universally to all kinds of apertures, including camera diaphragms. It can handle dynamic changes in the position of the aperture relative to the light source, which enables subtle movement or rotation of glare streaks. Spectra can also be simulated in the glare, since the intensity of diffraction depends on the wavelength of light. The resulting glare image is superimposed onto a given computer‐generated image containing high‐intensity light sources or reflections, aligning the center of the glare image to the high‐intensity areas. Our method is implemented as a multipass rendering software. By precomputing the dynamic glare image set and putting it into texture memory, the software runs at an interactive rate.

This paper proposes a general method of glare generation based on wave optics. A glare image is regarded as a result of Fraunhofer diffraction, which is equivalent to a 2D Fourier transform of the image of given apertures or obstacles. In conventional methods, the shapes of glare images are categorized according to their source apertures, such as pupils and eyelashes and their basic shapes (e.g. halos, coronas or radial streaks) are manually generated as templates, mainly based on statistical observation. Realistic variations of these basic shapes often depend on the use of random numbers. Our proposed method computes glare images fully automatically from aperture images and can be applied universally to all kinds of apertures, including camera diaphragms. It can handle dynamic changes in the position of the aperture relative to the light source, which enables subtle movement or rotation of glare streaks. Spectra can also be simulated in the glare, since the intensity of diffraction depends on the wavelength of light. The resulting glare image is superimposed onto a given computer-generated image containing high intensity light sources or reflections, aligning the center of the glare image to the high intensity areas. Our method is implemented as a multipass rendering software. By precomputing the dynamic glare image set and putting it into texture memory, the software runs at an interactive rate.

This paper presents a new algorithm for computing the points at which a ray intersects a rational Bezier surface patch, and also an algorithm for determining if an intersection point lies within a region trimmed by piecewise Bezier curves. Both algorithms are based on a recent innovation known as Bezier clipping, described herein. The intersection algorithm is faster than previous methods for which published performance data allow reliable comparison. It robustly finds all intersections without requiring special preprocessing.

A general purpose Cellular Array Processor(CAP) with distributed frame buffers for fast parallel subimage generation has been developed. CAP consists of many processor elements called cells. A cell has video memory for subimage storage, a window controller to map each subimage to an area on the monitor screen, and communication devices, in addition to ordinary microcomputer components such as MPU, RAM, and ROM. Image data in a cell is directly displayed via the video bus. The mapping pattern and the position on the screen of subimages can be changed dynamically. Various hidden surface algorithms can be implemented in CAP using mapping patterns appropriate for the algorithm.Our goal is an efficient interactive visual solid modeler. We adopted a general CSG hidden surface algorithm that enables display of both Boundary representation and Constructive Solid Geometry. A technique for hidden surface removal of general CSG models, requiring less memory space for large models in many cases, has been proposed. This technique subdivides the model into submodels by dividing the CSG tree at union nodes. Imagse of each submodel are generated by a CSG or a z-buffer algorithm. If a submodel is just a primitive, it is processed by the z-buffer algorithm, otherwise by the CSG algorithm. Hidden surface removal between submodels is done by comparing the z values for each pixel which are saved in the z-buffer.