286 research outputs found
A survey of real-time crowd rendering
In this survey we review, classify and compare existing approaches for real-time crowd rendering. We first overview character animation techniques, as they are highly tied to crowd rendering performance, and then we analyze the state of the art in crowd rendering. We discuss different representations for level-of-detail (LoD) rendering of animated characters, including polygon-based, point-based, and image-based techniques, and review different criteria for runtime LoD selection. Besides LoD approaches, we review classic acceleration schemes, such as frustum culling and occlusion culling, and describe how they can be adapted to handle crowds of animated characters. We also discuss specific acceleration techniques for crowd rendering, such as primitive pseudo-instancing, palette skinning, and dynamic key-pose caching, which benefit from current graphics hardware. We also address other factors affecting performance and realism of crowds such as lighting, shadowing, clothing and variability. Finally we provide an exhaustive comparison of the most relevant approaches in the field.Peer ReviewedPostprint (author's final draft
Real-time Realistic Rendering Of Nature Scenes With Dynamic Lighting
Rendering of natural scenes has interested the scientific community for a long time due to its numerous applications. The targeted goal is to create images that are similar to what a viewer can see in real life with his/her eyes. The main obstacle is complexity: nature scenes from real life contain a huge number of small details that are hard to model, take a lot of time to render and require a huge amount of memory unavailable in current computers. This complexity mainly comes from geometry and lighting. The goal of our research is to overcome this complexity and to achieve real-time rendering of nature scenes while providing visually convincing dynamic global illumination. Our work focuses on grass and trees as they are commonly visible in everyday life. We handle geometry and lighting complexities for grass to render millions of grass blades interactively with dynamic lighting. As for lighting complexity, we address real-time rendering of trees by proposing a lighting model that handles indirect lighting. Our work makes extensive use of the current generation of Graphics Processing Units (GPUs) to meet the real-time requirement and to leave the CPU free to carry out other tasks
Developing serious games for cultural heritage: a state-of-the-art review
Although the widespread use of gaming for leisure purposes has been well documented, the use of games to support cultural heritage purposes, such as historical teaching and learning, or for enhancing museum visits, has been less well considered. The state-of-the-art in serious game technology is identical to that of the state-of-the-art in entertainment games technology. As a result, the field of serious heritage games concerns itself with recent advances in computer games, real-time computer graphics, virtual and augmented reality and artificial intelligence. On the other hand, the main strengths of serious gaming applications may be generalised as being in the areas of communication, visual expression of information, collaboration mechanisms, interactivity and entertainment. In this report, we will focus on the state-of-the-art with respect to the theories, methods and technologies used in serious heritage games. We provide an overview of existing literature of relevance to the domain, discuss the strengths and weaknesses of the described methods and point out unsolved problems and challenges. In addition, several case studies illustrating the application of methods and technologies used in cultural heritage are presented
Serious Games in Cultural Heritage
Although the widespread use of gaming for leisure purposes has been well documented, the use of games to support cultural heritage purposes, such as historical teaching and learning, or for enhancing museum visits, has been less well considered. The state-of-the-art in serious game technology is identical to that of the state-of-the-art in entertainment games technology. As a result the field of serious heritage games concerns itself with recent advances in computer games, real-time computer graphics, virtual and augmented reality and artificial intelligence. On the other hand, the main strengths of serious gaming applications may be generalised as being in the areas of communication, visual expression of information, collaboration mechanisms, interactivity and entertainment. In this report, we will focus on the state-of-the-art with respect to the theories, methods and technologies used in serious heritage games. We provide an overview of existing literature of relevance to the domain, discuss the strengths and weaknesses of the described methods and point out unsolved problems and challenges. In addition, several case studies illustrating the application of methods and technologies used in cultural heritage are presented
Transition Contour Synthesis with Dynamic Patch Transitions
In this article, we present a novel approach for modulating the shape of transitions between terrain materials to produce detailed and varied contours where blend resolution is limited. Whereas texture splatting and blend mapping add detail to transitions at the texel level, our approach addresses the broader shape of the transition by introducing intermittency and irregularity. Our results have proven that enriched detail of the blend contour can be achieved with a performance competitive to existing approaches without additional texture, geometry resources, or asset preprocessing. We achieve this by compositing blend masks on-the-fly with the subdivision of texture space into differently sized patches to produce irregular contours from minimal artistic input. Our approach is of particular importance for applications where GPU resources or artistic input is limited or impractical
JUST NOTICEABLE DIFFERENCE SURVEY OF COMPUTER GENERATED IMAGERY USING NORMAL MAPS
Normal maps are widely used as a resource-efficient means of simulating detailed topology on 3D surfaces in the gaming, simulation, and film industries. However, as surface mesh density increases, it is unknown at what level of density these increases become no longer perceivable, and whether normal maps significantly affect this threshold. This study examined at what point participants were unable to discern differences between one level of mesh density and another using an adapted staircase model. Participants identified this threshold for five different organic character models. The averages of each of these thresholds were taken and compared against the results of a control group, which observed the same models without normal maps. The study found that the average threshold for discerning differences in level of detail occurred in the 3,000 to 14,000 polygon range for normal mapped models, and the 240,000 to 950,000 range for the control group. This analysis suggested that normal maps have a significant impact on the viewer\u27s ability to discern differences in detail, and that developing graphics beyond the range of 3,000 to 14,000 polygons is unnecessary for organic character models when normal maps are used
Computer Game Project Focused on Light Effects
Cílem této práce je představit a implementovat metody pro simulaci nerovností povrchu. Na začátku je vysvětlená potřebná teorie k Phongovmu osvětlení a následně teorie nejznámějších metod. Zaměření práce je především na Normal mapping a množství typů Parallax mappingů. Následně je přistoupené k implementaci těchto metod a k demonstrační aplikaci. Závěrem je uvedené krátké srovnání výkonů implementovaných metod.This bachelor thesis aims at introduction into methods for simulation of undulation of surface. There will be explained Phong reflection model and other best known theories at the beginning. The text deals with Normal mapping and various types of Parallax mapping. Then there will be demonstration application. There will be short comparison performances of implemented methods.
Screen Space Ambient Occlusion Using Partial Scene Representation
Screen space ambient occlusion (SSAO) is a technique in real-time rendering forapproximating amount by which a point on a surface is occluded by surrounding geometry, whichhelps in adding soft shadows to diffuse objects. Most of the current methods use the depth bufferas an approximation to scene geometry to sample the occlusion factor. We introduce a noveltechnique which uses a partial representation of the scene (here triangle information in screenspace) using compact triangle storage and a ray-marching approach to find a betterapproximation of the occlusion factor.Computer Scienc
Image-based rendering and synthesis
Multiview imaging (MVI) is currently the focus of some research as it has a wide range of applications and opens up research in other topics and applications, including virtual view synthesis for three-dimensional (3D) television (3DTV) and entertainment. However, a large amount of storage is needed by multiview systems and are difficult to construct. The concept behind allowing 3D scenes and objects to be visualized in a realistic way without full 3D model reconstruction is image-based rendering (IBR). Using images as the primary substrate, IBR has many potential applications including for video games, virtual travel and others. The technique creates new views of scenes which are reconstructed from a collection of densely sampled images or videos. The IBR concept has different classification such as knowing 3D models and the lighting conditions and be rendered using conventional graphic techniques. Another is lightfield or lumigraph rendering which depends on dense sampling with no or very little geometry for rendering without recovering the exact 3D-models.published_or_final_versio
Acceleration Techniques for Photo Realistic Computer Generated Integral Images
The research work presented in this thesis has approached the task of accelerating the
generation of photo-realistic integral images produced by integral ray tracing.
Ray tracing algorithm is a computationally exhaustive algorithm, which spawns one ray
or more through each pixel of the pixels forming the image, into the space containing
the scene. Ray tracing integral images consumes more processing time than normal
images. The unique characteristics of the 3D integral camera model has been analysed
and it has been shown that different coherency aspects than normal ray tracing can be
investigated in order to accelerate the generation of photo-realistic integral images.
The image-space coherence has been analysed describing the relation between rays and
projected shadows in the scene rendered. Shadow cache algorithm has been adapted in
order to minimise shadow intersection tests in integral ray tracing. Shadow intersection
tests make the majority of the intersection tests in ray tracing. Novel pixel-tracing
styles are developed uniquely for integral ray tracing to improve the image-space
coherence and the performance of the shadow cache algorithm. Acceleration of the
photo-realistic integral images generation using the image-space coherence information
between shadows and rays in integral ray tracing has been achieved with up to 41 % of
time saving. Also, it has been proven that applying the new styles of pixel-tracing does
not affect of the scalability of integral ray tracing running over parallel computers.
The novel integral reprojection algorithm has been developed uniquely through
geometrical analysis of the generation of integral image in order to use the tempo-spatial
coherence information within the integral frames. A new derivation of integral
projection matrix for projecting points through an axial model of a lenticular lens has
been established. Rapid generation of 3D photo-realistic integral frames has been
achieved with a speed four times faster than the normal generation
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