Bump Mapping Research Articles

Viewpoint-dependent lighting on polygonal holograms using bump mapping.

Holograms can be observed from different viewpoints, because light waves can be encoded to propagate in multiple directions. Thus, accurate holograms for 3D display should model viewpoint-dependent light reflections. We proposed a new, to the best of our knowledge, hologram generation method for objects represented by polygonal meshes, whose lighting changes as the viewer moves, all while rendering smooth shading using low-poly objects. The proposed method leverages bump mapping and converts it into a bump-phase map encoding the propagation frequency and then spreads the reflected light wave so that only a specific viewpoint can receive them. Simulation experiments with small pixel pitches confirm the method's high computational performance.

Excerpts from Everything Is a Projection (2020–present): Digital photography and 3D photogrammetry

In three-dimensional (3D) computer graphics, photography is treated not as the final product but as data to be extracted, information to be mapped onto and raw material to augment 3D models. Texture maps, normal maps and bump maps, created from photographic data, describe the reflectance properties of an object in a virtual scene. They give instructions to the render engine to calculate the correct pixel value, generating a near imperceptibly natural scene for the human eye. Computer graphics utilizes a network of images taken from different perspectives and at different scales to achieve photorealism. The project investigates one of many algorithmic visual systems that act as a backbone of virtual reality and gaming.

Study on Dynamic Surface Visualization Simulation Based on GPU

In the visual simulation of battlefield geographic environment, the realistic water surface effect can increase the reality of battlefield and enhance the immersion of training personnel, but the fluctuation of water body and the optical characteristics of water surface will also lead to the increase of algorithm complexity and the increase of data quantity, which will affect the fluency of the system. With the improvement of computer graphics hardware performance, in order to reduce the pressure of CPU, many complicated graphics computing has been transferred from CPU to GPU gradually. This chapter’s dynamic surface real-time rendering algorithm will make full use of the programmable characteristics of GPU and powerful computing power, the surface reflection refraction texture sampling, bump mapping, texture movement and other operations are put into the GPU, in order to ensure the surface fidelity, improve the rendering speed.

Image-based extrusion with realistic surface wrinkles

Abstract Per-pixel extrusion mapping is an image-based modeling and rendering technique that can be used in a large variety of computer graphic applications. This technique makes it possible to create geometries without polygonal meshes by extrusion of a basic form stored in a 2D binary image. It is available in four versions: basic extrusion, outward extrusion, beveled extrusion, and chamfered extrusion, and all allow the production of satisfactory results in terms of interactivity or visual quality. The problem is that the extruded surfaces do not exhibit microrelief effects and have a lack of realistic superficial wrinkles. To solve this problem, we proposed in this paper a combination of the per-pixel extrusion mapping and the bump mapping in order to add a microrelief effect to extruded surfaces without changing the basic geometry. For the real-time synchronization between the depth scaling of the microreliefs and the resulting shading, we proposed to use a scale factor to further disturb the normal in a function of depths.

Dynamic Sea Surface Scene Simulation Method Based on Bump Mapping

Dynamic Sea Surface Scene Simulation Method Based on Bump Mapping

Oil Painting Style Rendering Based on Kuwahara Filter

The Kuwahara filter can generate local smoothed color regions similar to hand-painted strokes, and therefore it can be used to image artistic rendering. However, the existing Kuwahara filtering methods often adopt a fixed-sized filter kernel, which leads to a homogeneous size of strokes. In view of this problem, a multi-scale anisotropic Kuwahara filtering method is proposed in this paper. By using image saliency as control information to adjust the size of filter kernel, strokes with abundant varied geometric scales are generated. This paper also presents an automatic rendering framework based on the proposed algorithm that automatically transforms images into an oil painting style. Using the image's orientation field of edge, edge gradient magnitude and image saliency to control the bump mapping, the senses of thickness and layers of oil painting's strokes are generated. By adopting this framework, an artistic oil painting style similar to the “impasto technique” can be simulated well.

A well-thought-out sensory protocol for screening of oxygen reactive species released from cancer cells

Facilely constructed metal nanoparticles with highly active sites, high economic impact, and stable electrocatalysts are crucial to developed sensory protocol for oxygen reactive species (ORS) released from cancer cells. In this study, we control the fabrication of uniformly arranged non-metal sphere catalysts that interfacially dressed by Ru nanoparticles for ultrasensitive ORS-sensing electrode patterns from cancer cells. The actively dressing of spherical ˜10 nm-Ru nano-buds/bumps that markedly interlinked entire micrometric surfaces of well-developed sulfur-doped carbon (S–C) spheres led to create catalytic surface defects through formation anisotropic wrinkling skins due to homogenous dispersion of bump mapping networks. These anisotropic protrusions create interfacial Ru@S–C surfaces with highly active catalytic sites, caves and grooves, roughness along the exterior S–C sphere–skin matrices, enabling a well-thought-out sensory signaling of ORS released from cancer cells. Specifically, our designed Ru@S–C modified electrode offers well-defined reading out transduction and end-point stimulus-responsive signaling of ORS molecules such as H2O2. The design of wrinkled Ru@S–C sphere sensory electrode provided H2O2-sensing assay with high sensitivity (314 μA μM−1 cm−2) and selectivity, low detection limit (25 nM based on 3σ), and wide linear ranges of detection reached up to 2 mM in physiological systems. Our findings indicated that highly active electrocatalysts based on wrinkling Ru@S–C can be employed for the in vitro detection of ORS released from cancer cells (HeLa cells) with high sensitivity and selectivity, low cytotoxicity, high biocompatibility, and fast response time, as well as detection of oxidative stress effects on living cells.

Revolution mapping with bump mapping support

Per-pixel Revolution Mapping is an image-based modeling and rendering technique or IBMR (Image-Based Modeling and Rendering). It consists of creating a virtual 3D objects without polygonal meshes. This technique uses a single RGBA texture that stores the needed data to generate the revolved surface. The main problem with this technique is that the 3D revolved models are rendered without realistic surface wrinkles. In this paper, we presented an improvement to enhance the realism of the 3D revolved models by combining the revolution mapping and the bump mapping. In order to synchronize between real-time depth scaling of the microrelief and the resulting shading, we have added a scaling factor that makes it possible to have a realistic depth animation. This new technique creates very convincing 3D models with realistic looking surface wrinkles and allows rendering at interactive frame rates.

Simulation of water surface using current consumer-level graphics hardware

Water surface visualization is an important research topic in computer graphics. This paper presents a novel method of water surface simulation by Secondary Distorted Textures (SDT), which realistically simulates and visualizes the reflection and refraction of calm water in real-time using current consumer-level hardware. The proposed method renders water surface using two stages of texture maps. 1. The first texture map stores the 3D geometries’ perspective reflection with respect to 3D perspective view; 2. The second texture map stores the distortion results of the first reflection map with lighting effects. Perlin noise is used to generate random height map. Reflection and refraction are obtained and stored in the secondary distorted texture map with Fresnel effects for each frame. At rendering pass, the SDT is directly tiled on water surface. This paper also discussed the rendering of transparent geometry, which have view-dependent of lighting effects features. Experimental results demonstrated that our method can render realistic geometry nearby dynamic water surface at the frame rates of 70-100 FPS by NVIDIA Quadro k5000 graphic card. The existing texture mapping and bump mapping methods were compared for illustrating that our method produced high realistic water surface without aliasing reflection.

2D and 3D virtual interactive laboratories of physics on Unity platform

Using the cross-platform game engine Unity, we develop virtual laboratories for PC, consoles, mobile devices and website as an innovative tool to study physics. There is extensive uptake of ICT in the teaching of science and its impact on the learning, and considering the limited availability of laboratories for physics teaching and the difficulties this causes in the learning of school students, we design the virtual laboratories to enhance studentâĂŹs knowledge of concepts in physics. To achieve this goal, we use Unity due to provide support bump mapping, reflection mapping, parallax mapping, dynamics shadows using shadows maps, full-screen post-processing effects and render-to-texture. Unity can use the best variant for the current video hardware and, if none are compatible, to use an alternative shader that may sacrifice features for performance. The control over delivery to mobile devices, web browsers, consoles and desktops is the main reason Unity is the best option among the same kind cross-platform. Supported platforms include Android, Apple TV, Linux, iOS, Nintendo 3DS line, macOS, PlayStation 4, Windows Phone 8, Wii but also an asset server and Nvidia’s PhysX physics engine which is the most relevant tool on Unity for our PhysLab.

Simplicial complex augmentation framework for bijective maps

Bijective maps are commonly used in many computer graphics and scientific computing applications, including texture, displacement, and bump mapping. However, their computation is numerically challenging due to the global nature of the problem, which makes standard smooth optimization techniques prohibitively expensive. We propose to use a scaffold structure to reduce this challenging and global problem to a local injectivity condition. This construction allows us to benefit from the recent advancements in locally injective maps optimization to efficiently compute large scale bijective maps (both in 2D and 3D), sidestepping the need to explicitly detect and avoid collisions. Our algorithm is guaranteed to robustly compute a globally bijective map, both in 2D and 3D. To demonstrate the practical applicability, we use it to compute globally bijective single patch parametrizations, to pack multiple charts into a single UV domain, to remove self-intersections from existing models, and to deform 3D objects while preventing self-intersections. Our approach is simple to implement, efficient (two orders of magnitude faster than competing methods), and robust, as we demonstrate in a stress test on a parametrization dataset with over a hundred meshes.

Bump Mapping for Isosurface Volume Rendering

Bump Mapping for Isosurface Volume Rendering

Evaluating Texture Compression Masking Effects Using Objective Image Quality Assessment Metrics.

Texture compression is widely used in real-time rendering to reduce storage and bandwidth requirements. Recent research in compression algorithms has explored both reduced fixed bit rate and variable bit rate algorithms. The results are evaluated at the individual texture level using mean square error, peak signal-to-noise ratio, or visual image inspection. We argue this is the wrong evaluation approach. Compression artifacts in individual textures are likely visually masked in final rendered images and this masking is not accounted for when evaluating individual textures. This masking comes from both geometric mapping of textures onto models and the effects of combining different textures on the same model such as diffuse, gloss, and bump maps. We evaluate final rendered images using rigorous perceptual error metrics. Our method samples the space of viewpoints in a scene, renders the scene from each viewpoint using variations of compressed textures, and then compares each to a ground truth using uncompressed textures from the same viewpoint. We show that masking has a significant effect on final rendered image quality, masking effects and perceptual sensitivity to masking varies by the type of texture, graphics hardware compression algorithms are too conservative, and reduced bit rates are possible while maintaining final rendered image quality.

The Effect of Wrinkles, Presentation Mode, and Intensity on the Perception of Facial Actions and Full-Face Expressions of Laughter

This article focuses on the identification and perception of facial action units displayed alone as well as the meaning decoding and perception of full-face synthesized expressions of laughter. We argue that the adequate representation of single action units is important in the decoding and perception of full-face expressions. In particular, we focus on three factors that may influence the identification and perception of single actions and full-face expressions: their presentation mode (static vs. dynamic), their intensity, and the presence of wrinkles. For the purpose of this study, we used a hybrid approach for animation synthesis that combines data-driven and procedural animations with synthesized wrinkles generated using a bump mapping method. Using such animation technique, we created animations of single action units and full-face movements of two virtual characters. Next, we conducted two studies to evaluate the role of presentation mode, intensity, and wrinkles in single actions and full-face context-free expressions. Our evaluation results show that intensity and presentation mode influence (1) the identification of single action units and (2) the perceived quality of the animation. At the same time, wrinkles (3) are useful in the identification of a single action unit and (4) influence the perceived meaning attached to the animation of full-face expressions. Thus, all factors are important for successful communication of expressions displayed by virtual characters.

Smart Surveillance Camera based on Pattern

Many research works has done on security surveillance camera system. Most of the experiment result shows good result in lab environment but the performance is not good enough when it apply to real life application. The experiment environment of research lab is different from outside world; therefore illumination condition is also different. Although false alarm works well in research environment but it has many problems in real world or dynamic background. False alarm is caused by shadow, smoke and light illumination condition and different type of noises these are major concern for effective surveillance camera system. So how to remove shadow effectively is more important than error detection and accurate result. Which is the main objective in surveillance system? The focus of our work is to remove the shadow efficiently. The computer vision researchers always give importance to the experimental issues such as image input color, morphological algorithms or moving object detection not to the real environmental issues. If the input image and shadow is similar with human then other algorithm not performs well while our proposed algorithm works very accurately. Experimental result shows our proposed algorithm can find out human and shadow from the input image. We have used different simulated illumination condition to find out the noise and successfully subtracted shadow. For our simulation environment we used unity 3D and Direct 10, tessellation (bump mapping).

A RANGE BASED METHOD FOR COMPLEX FACADE MODELING

Abstract. 3d modelling of Architectural Heritage does not follow a very well-defined way, but it goes through different algorithms and digital form according to the shape complexity of the object, to the main goal of the representation and to the starting data. Even if the process starts from the same data, such as a pointcloud acquired by laser scanner, there are different possibilities to realize a digital model. In particular we can choose between two different attitudes: the mesh and the solid model. In the first case the complexity of architecture is represented by a dense net of triangular surfaces which approximates the real surface of the object. In the other -opposite- case the 3d digital model can be realized by the use of simple geometrical shapes, by the use of sweeping algorithm and the Boolean operations. Obviously these two models are not the same and each one is characterized by some peculiarities concerning the way of modelling (the choice of a particular triangulation algorithm or the quasi-automatic modelling by known shapes) and the final results (a more detailed and complex mesh versus an approximate and more simple solid model). Usually the expected final representation and the possibility of publishing lead to one way or the other. In this paper we want to suggest a semiautomatic process to build 3d digital models of the facades of complex architecture to be used for example in city models or in other large scale representations. This way of modelling guarantees also to obtain small files to be published on the web or to be transmitted. The modelling procedure starts from laser scanner data which can be processed in the well known way. Usually more than one scan is necessary to describe a complex architecture and to avoid some shadows on the facades. These have to be registered in a single reference system by the use of targets which are surveyed by topography and then to be filtered in order to obtain a well controlled and homogeneous point cloud of the complex architecture. From the point cloud we can extract a false colour map depending on the distance of each point from the average plane. In this way we can represent each point of the facades by a height map in grayscale. In this operation it is important to define the scale of the final result in order to set the correct pixel size in the map. The following step is concerning the use of a modifier which is well-known in computer graphics. In fact the modifier Displacement allows to simulate on a planar surface the original roughness of the object according to a grayscale map. The value of gray is read by the modifier as the distance from the reference plane and it represents the displacement of the corresponding element of the virtual plane. Similar to the bump map, the displacement modifier does not only simulate the effect, but it really deforms the planar surface. In this way the 3d model can be use not only in a static representation, but also in dynamic animation or interactive application. The setting of the plane to be deformed is the most important step in this process. In 3d Max the planar surface has to be characterized by the real dimension of the façade and also by a correct number of quadrangular faces which are the smallest part of the whole surface. In this way we can consider the modified surface as a 3d raster representation where each quadrangular face (corresponding to traditional pixel) is displaced according the value of gray (= distance from the plane). This method can be applied in different context, above all when the object to be represented can be considered as a 2,5 dimension such as facades of architecture in city model or large scale representation. But also it can be used to represent particular effect such as deformation of walls in a complete 3d way.

The PSurface library

We describe PSurface, a C\(++\) library that allows to store and access piecewise linear maps between simplicial surfaces in \(\mathbb{R }^2\) and \(\mathbb{R }^3\). Piecewise linear maps can be used, e.g., to construct boundary approximations for finite element grids, and grid intersections for domain decomposition methods. In computer graphics the maps allow to build level-of-detail representations as well as texture- and bump maps. The PSurface library can be used as the basis for the implementation of a wide range of algorithms that use piecewise linear maps between triangulated surfaces. A few simple examples are given in this work. We document the data structures and algorithms and show how PSurface is used in the numerical analysis framework Dune and the visualization software Amira.

Driving 3D morphable models using shading cues

In this paper we show how surface orientation information inferred using shape-from-shading can be used to aid the process of fitting a 3D morphable model to an image of a face. We consider the problem of model dominance and show how shading constraints can be used to refine morphable model shape estimates, offering the possibility of exceeding the maximum possible accuracy of the model. We use this observation to motivate an optimisation scheme based on surface normal error. This ensures the fullest possible use of the information conveyed by the shading in an image. Moreover, our framework allows estimation of per-vertex albedo and bump maps which are not constrained to lie within the span of the model. This means the recovered model is capable of describing shape and reflectance phenomena not present in the training set. We show reconstruction and synthesis results and demonstrate that the shape and albedo estimates can be used for illumination insensitive recognition using only a single gallery image.

Monge mapping using hierarchical NURBS

Texture mapping is an efficient and effective tool in computer graphics and animation. While computationally very cost-effective, texture mapping may produce non-realistic appearances of shapes in 3D environment, especially when viewing closely. To improve the realism of 3D modeling, bump mapping technique is developed to add details with the 3D models on top of texture mapping. Bump mapping, however, offers only simple and visual enhancement. Displacement mapping technique can further improve the localized detail of geometry. In this paper, Monge mapping technique is developed for detail and local shape modification of NURBS represented geometry in a 3D environment. Based on multiresolution and refinement schemes, Hierarchical NURBS (H-NURBS) is first investigated to design a mechanism for the purpose of carrying localized geometric information. Monge mapping on H-NURBS patch can be easily performed via simple cut-and-paste operation. Parametric control of the local shapes is developed to facilitate easier and better 3D local modeling.

Bump Mapping Unparametrized Surfaces on the GPU

Abstract Original bump mapping is only defined for surfaces with a known surface parametrization. In this paper a new method, for the GPU, is presented which does not use such a given parametrization. To compute the perturbed normal, the only inputs used are the surface position, the height value and the original normal. The method decouples bump mapping from the primitive type, thus allowing for a higher degree of proceduralism in generation of both the height value and the surface.