Klasifikasi Shadow Algorithm

Dalam bidang Grafika Komputer Shadow Algorithm merupakan salah satu kajian yang menarik. Shadow Algorithm, suatu algoritma yang digunakan untuk menghasilkan sebuah bayangan objek pada suatu scene. Pengembangan berbagai shadow algorithm sudah banyak dilakukan. Klasifikasi algoritma menurut tipe interaktifitasnya dan hasil render dengan cepat (immediate render), algoritma terbagi menjadi dua yaitu real-time dan non-real-time. Sedangkan melihat dari bayangan yang dihasilkan terdapat dua jenis yaitu hard shadow dan soft shadow

Real-Time Shadow Using a Combination of Stencil and The Z-Buffer

In this paper we describe a real-time shadow generation with volume shadow algorithm in virtual environment that is illuminated by light sources with possibility to move separately. This algorithm uses the combination of stencil and Z-buffers to generate shadow volume. It is simple to understand and implement. We have significantly improved and implemented recent techniques that are used in shadow volume algorithms using stencil buffers especially in order to recognize silhouette, reduce the number of shadow polygons and also redundant length of each triangles that makes the volume shadow. This work may be applied in commercial games or other virtual reality systems

Penumbra maps: approximate soft shadows in real-time

Journal ArticleGenerating soft shadows quickly is difficult. Few techniques have enough flexibility to interactively render soft shadows in scenes with arbitrarily complex occluders and receivers. This paper introduces the penumbra map, which extends current shadow map techniques to interactively approximate soft shadows. Using object silhouette edges, as seen from the center of an area light, a map is generated containing approximate penumbral regions. Rendering requires two lookups, one into each the penumbra and shadow maps. Penumbra maps allow arbitrary dynamic models to easily shadow themselves and other nearby complex objects with plausible penumbrae

Penumbra maps

technical reportGenerating soft shadows quickly is difficult. Few techniques have enough flexibility to interactively render soft shadows in scenes with arbitrarily complex occluders and receivers. This paper introduces the penumbra map, which extends current shadow map techniques to interactively approximate soft shadows. Using object silhouette edges, as seen from the center of an area light, a map is generated containing approximate penumbral regions. Rendering requires two lookups, one into each the penumbra and shadow maps. Penumbra maps allow arbitrary dynamic models to easily shadow themselves and other nearby complex objects with plausible penumbrae

A Beam Tracing with Precise Antialiasing for Polyhedral Scenes

International audienceRay tracing is one of the most important rendering techniques used in computer graphics. A fundamental problem of classical ray tracers is the well-known aliasing. With small objects, or small shadows, aliasing becomes a crucial problem to solve. Beam tracers can be considered as an extension of classical ray tracers. They replace the concept of infinitesimal ray by that of beam but they are generally more complex than ray tracers. The new method presented in this paper is a high quality beam tracer that provides a robust and general antialiasing for polyhedral scenes. Compared to similar beam tracers, this method has some major advantages: - complex and expensive computations of conventional beam-object intersection are entirely avoided, so an extension to some non polyhedral scenes such as CSG ones is possible; - usual approximations or complex approaches for refraction computations are avoided. Moreover, this method is entirely compatible with the usual improvements of classical ray tracing (spatial subdivisions or hierarchical bounding volumes)

Real-Time Shadow Using a Combination of Stencil and The Z-Buffer

In this paper we describe a real-time shadow generation with volume shadow algorithm in virtual environment that is illuminated by light sources with possibility to move separately. This algorithm uses the combination of stencil and Z-buffers to generate shadow volume. It is simple to understand and implement. We have significantly improved and implemented recent techniques that are used in shadow volume algorithms using stencil buffers especially in order to recognize silhouette, reduce the number of shadow polygons and also redundant length of each triangles that makes the volume shadow. This work may be applied in commercial games or other virtual reality systems

Klasifikasi Shadow Algorithm

Dalam bidang Grafika Komputer Shadow Algorithm merupakan salah satu kajian yang menarik. Shadow Algorithm, suatu algoritma yang digunakan untuk menghasilkan sebuah bayangan objek pada suatu scene. Pengembangan berbagai shadow algorithm sudah banyak dilakukan. Klasifikasi algoritma menurut tipe interaktifitasnya dan hasil render dengan cepat (immediate render), algoritma terbagi menjadi dua yaitu real-time dan non-real-time. Sedangkan melihat dari bayangan yang dihasilkan terdapat dua jenis yaitu hard shadow dan soft shadow

Rendering of Shadows in a Scene with DirectX

Tato práce pojednává o metodách zobrazení stínů, jejich analýze a implementaci v rozhraní DirectX 11. Teoretická část popisuje historický vývoj použití stínů v 3D aplikácích a jednotlivé algoritmy pro výpočet stínů. V rámci práce jsou na demonstrační aplikaci porovnány zhlediska výkonu, náročnosti implementace a kvality výstupu 2 varianty algoritmu shadow mapping pro všesměrová světla - s využitím cube mappingu a parabolické projekce, každá s pěti různě optimalizovanými implementacemi.This work discusses shadowing methods, analyses them and describes implementation in DirectX 11 API. Theoretical part describes historical evolution of shadow usage in 3D applications and also analyzes shadowing algorithms. This work compares 2 variants of shadow mapping algorithm for omnidirectional lights, based on cube mapping and paraboloid projection, on demo application using quality, performance and implementation aspects.