203 research outputs found
Shadow Mapping or Shadow Volume?
In this paper two techniques of shadow generation are described. Volume shadow is geometric base but shadow mapping is image base. Silhouette detection is a most expensive step to create volume shadow. Two algorithms to recognize silhouette are introduced. Stencil buffer and Z- buffer are two other tools for creating shadow by volume shadow technique. Both algorithms are implemented in virtual environment with moveable light source. Triangular method and the Visible-non visible method are introduced. The recent traditional silhouette detection and implementation techniques used in volume shadow algorithm are improved. With introduce flowchart of both algorithms, the last volume shadow algorithm using stencil buffer is rewritten. A very simple algorithm to create volume shadow is proposed. The last shadow mapping algorithm is rewritten. These techniques are poised to bring realism into commercial games. It may be use in virtual reality applications
An Overview on Base Real-Time Shadow Techniques in Virtual Environments
Shadows are elegant to create a realistic scene in virtual environments. Variety types of shadow techniques encourage us to prepare an overview on all base shadow techniques. Non real-time and real-time techniques are big subdivision of shadow generation. In non real-time techniques ray tracing, ray casting and radiosity are well known and deeply described. Radiosity implemented to create very realistic shadow on non real-time scene. Although traditional radiosity algorithm is difficult to implement, we have proposed a simple one. The proposed pseudo code is easier to understand and implement. Ray tracing used to prevent of collision of movement objects. Projection shadow, shadow volume and shadow mapping are used to create real-time shadow in virtual environments. We have used projection shadow for some objects are static and have shadow on flat surface. Shadow volume used to create accurate shadow with sharp outline. Shadow mapping that is the base of most recently techniques is reconstructed. The reconstruct algorithm gives some new idea to propose another algorithm based on shadow mapping. Â
Smoke and Shadows: Rendering and Light Interaction of Smoke in Real-Time Rendered Virtual Environments
Realism in computer graphics depends upon digitally representing what we see in the world with careful attention to detail, which usually requires a high degree of complexity in modelling the scene. The inevitable trade-off between realism and performance means that new techniques that aim to improve the visual fidelity of a scene must do so without compromising the real-time rendering performance. We describe and discuss a simple method for realistically casting shadows from an opaque solid object through a GPU (graphics processing unit) based particle system representing natural phenomena, such as smoke
3D simulation of complex shading affecting PV systems taking benefit from the power of graphics cards developed for the video game industry
Shading reduces the power output of a photovoltaic (PV) system. The design
engineering of PV systems requires modeling and evaluating shading losses. Some
PV systems are affected by complex shading scenes whose resulting PV energy
losses are very difficult to evaluate with current modeling tools. Several
specialized PV design and simulation software include the possibility to
evaluate shading losses. They generally possess a Graphical User Interface
(GUI) through which the user can draw a 3D shading scene, and then evaluate its
corresponding PV energy losses. The complexity of the objects that these tools
can handle is relatively limited. We have created a software solution, 3DPV,
which allows evaluating the energy losses induced by complex 3D scenes on PV
generators. The 3D objects can be imported from specialized 3D modeling
software or from a 3D object library. The shadows cast by this 3D scene on the
PV generator are then directly evaluated from the Graphics Processing Unit
(GPU). Thanks to the recent development of GPUs for the video game industry,
the shadows can be evaluated with a very high spatial resolution that reaches
well beyond the PV cell level, in very short calculation times. A PV simulation
model then translates the geometrical shading into PV energy output losses.
3DPV has been implemented using WebGL, which allows it to run directly from a
Web browser, without requiring any local installation from the user. This also
allows taken full benefits from the information already available from
Internet, such as the 3D object libraries. This contribution describes, step by
step, the method that allows 3DPV to evaluate the PV energy losses caused by
complex shading. We then illustrate the results of this methodology to several
application cases that are encountered in the world of PV systems design.Comment: 5 page, 9 figures, conference proceedings, 29th European Photovoltaic
Solar Energy Conference and Exhibition, Amsterdam, 201
Interior Batik Gallery Using Normal Mapping For Virtual Reality
We present an 3D Modelling object for batik Gallery in virtual reality with textured material photo, Lighting effect and primitive mess with Normal Mapping Metthod. Normal Mapping is one of many method  to give  depht Impression texture and detail for object without  many  polycount, so we can get  efficiency of the computer work without loss of detail desired. in this research we try to explain  several techniques in making batik Gallery design textures with modeling 3D, The methods include stage Normal Mapping, Environment maps, bump maps, and shadow maps. The next proscess we can use Directional Light and Point Light for each object to get the  impression of depth and real dimension for each  texture. The result of this research is to improve the modern batik consept and patterns with immersive 3D Room in Virtual realit
To Combine Silhouette Detection and Stencil Buffer for Generating Real-Time Shadow
This paper describes one of the best methods to generate real-time shadow that called volume shadow. Volume shadow algorithm is possible to implement for virtual environment with moveable illuminated light source. We improve to find silhouette and implementation of the last techniques used in shadow volume algorithms, and limitation of length of volume of each semi-polygon that makes between silhouette's edge and shadow receiver. We rewrite the last volume shadow algorithm using stencil buffer and propose a pseudo code in OpenGl. The best tools that we have used in this algorithm are stencil buffer and Z-buffer.It makes realistic commercial games or it can be use in virtual reality systems
A Fast Silhouette Detection Algorithm for Shadow Volumes in Augmented Reality
Real-time shadow generation in virtual environments and Augmented Reality (AR) was always a hot topic in the last three decades. Lots of calculation for shadow generation among AR needs a fast algorithm to overcome this issue and to be capable of implementing in any real-time rendering. In this paper, a silhouette detection algorithm is presented to generate shadows for AR systems. Δ+algorithm is presented based on extending edges of occluders to recognize which edges are silhouettes in the case of real-time rendering. An accurate comparison between the proposed algorithm and current algorithms in silhouette detection is done to show the reduction calculation by presented algorithm. The algorithm is tested in both virtual environments and AR systems. We think that this algorithm has the potential to be a fundamental algorithm for shadow generation in all complex environments
Fuzzy Soft Shadow in Augmented Reality Systems
Realistic soft shadows in Augmented Reality (AR) is a fascinating topic in computer graphics. Many researchers are involved to have a significant improvement on this demand. In this paper, we have presented a new technique to produce soft shadows using one of the well-known methods in mathematics called Fuzzy Logic. Fuzzy logic is taken into account to generate the realistic soft shadows in AR. The wide light source is split into some parts that each of them plays the rule of a single light source. The desired soft shadow is generated by splitting the wide light source into multiple parts and considering each part as a single light source. The method which we called Fuzzy Soft Shadow is employed in AR to enhance the quality of semi-soft shadows and soft shadows
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