Screen-space VPL propagation for real-time indirect lighting

Ambient occlusion (AO) is a popular rendering technique that enhances depth perception and realism by darkening locations that are less exposed to ambient light (e.g., corners and creases). In real-time applications, screen-space variants, relying on the depth buffer, are used due to their high performance and good visual quality. However, these only take visible surfaces into account, resulting in inconsistencies, especially during motion. Stochastic-Depth Ambient Occlusion is a novel AO algorithm that accounts for occluded geometry by relying on a stochastic depth map, capturing multiple scene layers per pixel at random. Hereby, we efficiently gather missing information in order to improve upon the accuracy and spatial stability of conventional screen-space approximations, while maintaining real-time performance. Our approach integrates well into existing rendering pipelines and improves the robustness of many different AO techniques, including multi-view solutions.

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REAL-TIME DISPERSIVE REFRACTION WITH ADAPTIVE SPECTRAL MAPPING

International Journal of Artificial Intelligence Tools ◽

10.1142/s0218213013600191 ◽

2013 ◽

Vol 22 (06) ◽

pp. 1360019

Author(s):

DAMON BLANCHETTE ◽

EMMANUEL AGU

Keyword(s):

Real Time ◽

White Light ◽

Spectral Mapping ◽

Mapping Algorithm ◽

Physically Based ◽

Refractive Medium ◽

Interactive Frame ◽

Screen Space ◽

Special Case ◽

Novel Algorithm

Spectral rendering, or the synthesis of images by taking into account the constituent wavelengths of white light, enables the rendering of iridescent colors caused by phenomena such as dispersion, diffraction, interference and scattering. Caustics, the focusing and defocusing of light through a refractive medium, can be interpreted as a special case of dispersion where all the wavelengths travel along the same paths. In this paper we extend Adaptive Caustic Mapping (ACM), a previously proposed caustics mapping algorithm, to handle physically-based dispersion. Because ACM can display caustics in real-time, it is amenable to extension to handle the more general case of dispersion. We also present a novel algorithm for filling in the gaps that occur due to discrete sampling of the spectrum. Our proposed method runs in screen-space, and is fast enough to display plausible dispersion phenomena at real-time and interactive frame rates.

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Irregular Morphing for Real-Time Rendering of Large Terrain

ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences ◽

10.5194/isprsarchives-xli-b3-755-2016 ◽

2016 ◽

Vol XLI-B3 ◽

pp. 755-762 ◽

Cited By ~ 2

Author(s):

Sid'Ali Kalem ◽

Assia Kourgli

Keyword(s):

Real Time ◽

Adaptive Sampling ◽

Approximation Error ◽

Surface Characteristics ◽

Remote Visualization ◽

Terrain Rendering ◽

Real Time Processing ◽

Tile Size ◽

Multi Resolution Analysis ◽

Screen Space

The following paper proposes an alternative approach to the real-time adaptive triangulation problem. A new region-based multi-resolution approach for terrain rendering is described which improves on-the-fly the distribution of the density of triangles inside the tile after selecting appropriate Level-Of-Detail by an adaptive sampling. This proposed approach organizes the heightmap into a QuadTree of tiles that are processed independently. This technique combines the benefits of both Triangular Irregular Network approach and region-based multi-resolution approach by improving the distribution of the density of triangles inside the tile. Our technique morphs the initial regular grid of the tile to deformed grid in order to minimize approximation error. The proposed technique strives to combine large tile size and real-time processing while guaranteeing an upper bound on the screen space error. Thus, this approach adapts terrain rendering process to local surface characteristics and enables on-the-fly handling of large amount of terrain data. Morphing is based-on the multi-resolution wavelet analysis. The use of the D2WT multi-resolution analysis of the terrain height-map speeds up processing and permits to satisfy an interactive terrain rendering. Tests and experiments demonstrate that Haar B-Spline wavelet, well known for its properties of localization and its compact support, is suitable for fast and accurate redistribution. Such technique could be exploited in client-server architecture for supporting interactive high-quality remote visualization of very large terrain.

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Screen Space Ambient Occlusion Based Multiple Importance Sampling for Real-Time Rendering

3D Research ◽

10.1007/s13319-017-0152-9 ◽

2017 ◽

Vol 9 (1) ◽

Cited By ~ 1

Author(s):

Abd El Mouméne Zerari ◽

Mohamed Chaouki Babahenini

Keyword(s):

Real Time ◽

Importance Sampling ◽

Multiple Importance Sampling ◽

Ambient Occlusion ◽

Screen Space

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Rendering Trees with Indirect Lighting in Real Time

Computer Graphics Forum ◽

10.1111/j.1467-8659.2008.01257.x ◽

2008 ◽

Vol 27 (4) ◽

pp. 1189-1198 ◽

Cited By ~ 7

Author(s):

K. Boulanger ◽

K. Bouatouch ◽

S. Pattanaik

Keyword(s):

Real Time ◽

Indirect Lighting

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Fast Image-Based Ambient Occlusion IBAO

International Journal of Virtual Reality ◽

10.20870/ijvr.2011.10.4.2830 ◽

2011 ◽

Vol 10 (4) ◽

pp. 61-65

Author(s):

Robert Sajko ◽

Zeljka Mihajlovic

Keyword(s):

Real Time ◽

Sampling Method ◽

Dynamic Scenes ◽

Heuristic Function ◽

Ambient Occlusion ◽

Improved Performance ◽

Straightforward Solution ◽

And Performance ◽

Screen Space

The quality of computer rendering and perception of realism greatly depend on the shading method used to implement the interaction of light with the surfaces of objects in a scene. Ambient occlusion (AO) enhances the realistic impression of rendered objects and scenes. Properties that make Screen Space Ambient Occlusion (SSAO) interesting for real-time graphics are scene complexity independence, and support for fully dynamic scenes. However, there are also important issues with current approaches: poor texture cache use, introduction of noise, and performance swings. In this paper, a straightforward solution is presented. Instead of a traditional, geometry-based sampling method, a novel, image-based sampling method is developed, coupled with a revised heuristic function for computing occlusion. Proposed algorithm harnessing GPU power improves texture cache use and reduces aliasing artifacts. Two implementations are developed, traditional and novel, and their comparison reveals improved performance and quality of the proposed algorithm.

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