scholarly journals Hash-Based Hierarchical Caching and Layered Filtering for Interactive Previews in Global Illumination Rendering

2020 ◽  
Author(s):  
Thorsten Roth ◽  
Martin Weier ◽  
Pablo Bauszat ◽  
André Hinkenjann ◽  
Yongmin Li
Keyword(s):  
Monte Carlo ◽  
Computational Complexity ◽  
Global Illumination ◽  
Ground Truth ◽  
Low Noise ◽  
Constant Time ◽  
Efficient Storage ◽  
Diffuse Illumination ◽  
Interactive Frame ◽  
Memory Efficient

Modern Monte-Carlo-based rendering systems still suffer from the computational complexity involved in the generation of noise-free images, making it challenging to synthesize interactive previews. We present a framework suited for rendering such previews of static scenes using a caching technique that builds upon a linkless octree. Our approach allows for memory-efficient storage and constant-time lookup to cache diffuse illumination at multiple hitpoints along the traced paths. Non-diffuse surfaces are dealt with in a hybrid way in order to reconstruct view-dependent illumination while maintaining interactive frame rates. By evaluating the visual fidelity against ground truth sequences and by benchmarking, we show that our approach compares well to low-noise path traced results, but with a greatly reduced computational complexity allowing for interactive frame rates. This way, our caching technique provides a useful tool for global illumination previews and multi-view rendering.

scholarly journals Hash-Based Hierarchical Caching and Layered Filtering for Interactive Previews in Global Illumination Rendering

Computers ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 17
Author(s):  
Thorsten Roth ◽  
Martin Weier ◽  
Pablo Bauszat ◽  
André Hinkenjann ◽  
Yongmin Li
Keyword(s):  
Monte Carlo ◽  
Computational Complexity ◽  
Global Illumination ◽  
Ground Truth ◽  
Low Noise ◽  
Constant Time ◽  
Efficient Storage ◽  
Diffuse Illumination ◽  
Interactive Frame ◽  
Memory Efficient

Modern Monte-Carlo-based rendering systems still suffer from the computational complexity involved in the generation of noise-free images, making it challenging to synthesize interactive previews. We present a framework suited for rendering such previews of static scenes using a caching technique that builds upon a linkless octree. Our approach allows for memory-efficient storage and constant-time lookup to cache diffuse illumination at multiple hitpoints along the traced paths. Non-diffuse surfaces are dealt with in a hybrid way in order to reconstruct view-dependent illumination while maintaining interactive frame rates. By evaluating the visual fidelity against ground truth sequences and by benchmarking, we show that our approach compares well to low-noise path-traced results, but with a greatly reduced computational complexity, allowing for interactive frame rates. This way, our caching technique provides a useful tool for global illumination previews and multi-view rendering.

scholarly journals Multiple particle filtering for tracking wireless agents via Monte Carlo likelihood approximation

2019 ◽  
Vol 2019 (1) ◽  
Author(s):  
Stephan Schlupkothen ◽  
Gerd Ascheid
Keyword(s):  
Monte Carlo ◽  
Computational Complexity ◽  
Particle Filtering ◽  
Gaussian Approximation ◽  
State Of The Art ◽  
Approximation Techniques ◽  
Accurate Localization ◽  
Likelihood Approximation ◽  
Current State ◽  
Multiple Particle

Abstract The localization of multiple wireless agents via, for example, distance and/or bearing measurements is challenging, particularly if relying on beacon-to-agent measurements alone is insufficient to guarantee accurate localization. In these cases, agent-to-agent measurements also need to be considered to improve the localization quality. In the context of particle filtering, the computational complexity of tracking many wireless agents is high when relying on conventional schemes. This is because in such schemes, all agents’ states are estimated simultaneously using a single filter. To overcome this problem, the concept of multiple particle filtering (MPF), in which an individual filter is used for each agent, has been proposed in the literature. However, due to the necessity of considering agent-to-agent measurements, additional effort is required to derive information on each individual filter from the available likelihoods. This is necessary because the distance and bearing measurements naturally depend on the states of two agents, which, in MPF, are estimated by two separate filters. Because the required likelihood cannot be analytically derived in general, an approximation is needed. To this end, this work extends current state-of-the-art likelihood approximation techniques based on Gaussian approximation under the assumption that the number of agents to be tracked is fixed and known. Moreover, a novel likelihood approximation method is proposed that enables efficient and accurate tracking. The simulations show that the proposed method achieves up to 22% higher accuracy with the same computational complexity as that of existing methods. Thus, efficient and accurate tracking of wireless agents is achieved.

View-independent Modeling of Lighting Systems by Local Estimations of the Monte Carlo Method

Vestnik MEI ◽  
2021 ◽  
Vol 1 (1) ◽  
pp. 70-75
Author(s):  
Vladimir P. Budak ◽  
◽  
Viktor S. Zheltov ◽  
Tatyana V. Meshkova ◽  
Viktor D. Chembaev ◽  
...  
Keyword(s):  
Monte Carlo ◽  
Angular Distribution ◽  
Monte Carlo Method ◽  
Light Source ◽  
Global Illumination ◽  
The Monte Carlo Method ◽  
Computer Aided ◽  
Radiosity Equation ◽  
Lighting Systems ◽  
Independent Calculation

Computer-aided designing of lighting systems has been remaining of relevance for more than ten years. The most popular CAD packages for calculating lighting systems, such as DIAlux and Relux, are based on solving the radiosity equation. By using this equation, the illuminance distributions can be modeled, based on which the standardized quantitative lighting characteristics can be calculated. However, the human eye perceives brightness, not illuminance. The qualitative parameters of lighting are closely linked with the spatial-angular distribution of brightness, for calculation of which it is necessary to solve the global illumination equation. An analysis of the engineering matters concerned with designing of lighting systems points to the obvious need for a so-called view-independent calculation of lighting scenes, which means the possibility to visually represent a scene from different positions of sighting (a camera). The approach based on local estimations of the Monte Carlo method as one of efficient techniques for solving the global illumination equation is considered, and an algorithm for view-independent modeling based on the local estimations method is presented. Various algorithms for solving the problem of searching the intersection for the casted beams from a light source with the studied illumination scene are investigated.

scholarly journals SLM-Transform: A Method for Memory-Efficient Indexing of Spectra for Database Search in LC-MS/MS Proteomics

2019 ◽  
Author(s):  
Muhammad Haseeb ◽  
Muaaz G. Awan ◽  
Alexander S. Cadigan ◽  
Fahad Saeed
Keyword(s):  
Peptide Identification ◽  
Transformation Method ◽  
Database Search ◽  
Constant Time ◽  
Theoretical Spectrum ◽  
Post Translational Modifications ◽  
Stored Information ◽  
Indexing Technique ◽  
Memory Constraints ◽  
Memory Efficient

AbstractThe most commonly used strategy for peptide identification in shotgun LC-MS/MS proteomics involves searching of MS/MS data against an in-silico digested protein sequence database. Typically, the digested peptide sequences are indexed into the memory to allow faster search times. However, subjecting a database to post-translational modifications (PTMs) during digestion results in an exponential increase in the number of peptides and therefore memory consumption. This limits the usage of existing fragment-ion based open-search algorithms for databases with several PTMs. In this paper, we propose a novel fragment-ion indexing technique which is analogous to suffix array transformation and allows constant time querying of indexed ions. We extend our transformation method, called SLM-Transform, by constructing ion buckets that allow querying of all indexed ions by mass by only storing information on distribution of ion-frequencies within buckets. The stored information is used with a regression technique to locate the position of ions in constant time. Moreover, the number of theoretical b- and y-ions generated and indexed for each theoretical spectrum are limited. Our results show that SLM-Transform allows indexing of up to 4x peptides than other leading fragment-ion based database search tools within the same memory constraints. We show that SLM-Transform based index allows indexing of over 83 million peptides within 26GB RAM as compared to 80GB required by MSFragger. Finally, we show the constant ion retrieval time for SLM-Transform based index allowing ultrafast peptide search speeds.Source code will be made available at: https://github.com/pcdslab/slmindex

scholarly journals Efficient ancestry and mutation simulation with msprime 1.0

Genetics ◽  
2021 ◽  
Author(s):  
Franz Baumdicker ◽  
Gertjan Bisschop ◽  
Daniel Goldstein ◽  
Graham Gower ◽  
Aaron P Ragsdale ◽  
...  
Keyword(s):  
Population Genetics ◽  
Data Structure ◽  
Software Quality ◽  
High Performance ◽  
Sequence Data ◽  
Ground Truth ◽  
Development Model ◽  
Ground Truth Data ◽  
Open Source Development ◽  
Memory Efficient

Abstract Stochastic simulation is a key tool in population genetics, since the models involved are often analytically intractable and simulation is usually the only way of obtaining ground-truth data to evaluate inferences. Because of this, a large number of specialized simulation programs have been developed, each filling a particular niche, but with largely overlapping functionality and a substantial duplication of effort. Here, we introduce msprime version 1.0, which efficiently implements ancestry and mutation simulations based on the succinct tree sequence data structure and the tskit library. We summarize msprime’s many features, and show that its performance is excellent, often many times faster and more memory efficient than specialized alternatives. These high-performance features have been thoroughly tested and validated, and built using a collaborative, open source development model, which reduces duplication of effort and promotes software quality via community engagement.

scholarly journals Local estimations of Monte Carlo method with the object spectral representation in the solution of global illumination

2012 ◽  
Vol 4 (1) ◽  
pp. 75-84 ◽  
Author(s):  
Vladimir Pavlovich Budak ◽  
Victor Sergeevich Zheltov ◽  
Timofey Kirrilovich Kalakutsky
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Method ◽  
Spectral Representation ◽  
Global Illumination

scholarly journals ATMOSPHERICALLY COMPENSATED SHAPE FROM SHADING ON THE MARTIAN SURFACE: TOWARDS THE PERFECT DIGITAL TERRAIN MODEL OF MARS

2019 ◽  
Vol XLII-2/W13 ◽  
pp. 1405-1411
Author(s):  
M. Hess ◽  
K. Wohlfarth ◽  
A. Grumpe ◽  
C. Wöhler ◽  
O. Ruesch ◽  
...  
Keyword(s):  
Digital Terrain Model ◽  
Ground Truth ◽  
Atmospheric Model ◽  
Shape From Shading ◽  
Initial Surface ◽  
Atmospheric Parameters ◽  
Martian Surface ◽  
Atmospheric Compensation ◽  
Digital Terrain ◽  
Diffuse Illumination

<p><strong>Abstract.</strong> We have expanded our existing Shape and Albedo from Shading framework which has primarily been used to generate Digital Terrain Models (DTMs) of the Lunar Surface. The extension consists of an atmospheric model such that the approach can be applied to Mars which is covered by a thin atmosphere. The atmospheric model includes attenuation by the atmosphere, diffuse illumination of the surface and scattering from the atmosphere into the direction of the sensor with physically motivated parameters. To estimate the newly introduced atmospheric parameters without additional CRISM measurements, the radiance image and an initializing surface are used. The initial surface is derived from stereo images and serves two purposes. On the one hand, it is the height constraint of the SfS algorithm and on the other hand, it is used for estimating the atmospheric parameters. Relying on this estimation, the aforementioned Shape and Albedo from Shading method is carried out. The results show a considerable improvement compared to DTMs derived with stereo algorithms. The omnipresent stereo artifacts such as pixel locking and mismatches are smoothed out and small details are reconstructed convincingly. The procedure is then compared to the reconstruction without atmospheric compensation. Images in which shadows are present benefit from this method because shadows can now be described by the diffuse illumination of the surface. The reconstruction results indicate the viability of the approach since it can produce convincing DTMs compared to HiRISE ground truth.</p>

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