|
|
Adjoint-Driven Importance Sampling in Light Transport Simulation
Vorba, Jiří ; Křivánek, Jaroslav (advisor) ; Keller, Alexander (referee) ; Wann Jensen, Henrik (referee)
Title: Adjoint-Driven Importance Sampling in Light Transport Simulation Author: RNDr. Jiří Vorba Department: Department of Software and Computer Science Education Supervisor: doc. Ing. Jaroslav Křivánek, Ph.D., Department of Software and Computer Science Education Abstract: Monte Carlo light transport simulation has recently been adopted by the movie industry as a standard tool for producing photo realistic imagery. As the industry pushes current technologies to the very edge of their possibilities, the unprecedented complexity of rendered scenes has underlined a fundamental weakness of MC light transport simulation: slow convergence in the presence of indirect illumination. The culprit of this poor behaviour is that the sam- pling schemes used in the state-of-the-art MC transport algorithms usually do not adapt to the conditions of rendered scenes. We base our work on the ob- servation that the vast amount of samples needed by these algorithms forms an abundant source of information that can be used to derive superior sampling strategies, tailored for a given scene. In the first part of this thesis, we adapt general machine learning techniques to train directional distributions for biasing scattering directions of camera paths towards incident illumination (radiance). Our approach allows progressive...
|
|
|
Editor for project IVE - objects and areas
Vorba, Jiří ; Brom, Cyril (advisor) ; Poch, Tomáš (referee)
The main goal of this work is to implement an editor for IVE which is the simulator of virtual humans developed at MFF UK. Our editor should primarily open up IVE for teaching of algorithms for control of virtual humans. The part of the work is also the search from field of tools for prototyping control algorithms of virtual agents in computer games and teaching applications. There is also introduced the project IVE itself. Also our own demo world was made for testing purposes and there arised two tutorials which are part of the extensive user documentation.
|
|
|
Design and evaluation of a user inteface for cinematic lighting
Růžička, Martin ; Křivánek, Jaroslav (advisor) ; Vorba, Jiří (referee)
This diploma thesis deals with global illumination and generally with the process of illumination of prepared scenes. A program for illumination management was written for this purpose. It can manage both direct and indirect illumination in interactive time. Simple and comfortable user interface allows for addition, deletion and change in light settings. Different types of both point and area lights are supported. In the course of all work, the program displays current illumination of the scene. With the help of this application, a series of different experiments will be carried out. We will explore the way users work during illumination, the way they perceive different properties of global illumination, various options of its control and its comparison with common direct illumination.
|
|
|
Optimal strategy for connecting light paths in bidirectional methods for global ilumination computation
Vorba, Jiří ; Křivánek, Jaroslav (advisor) ; Wilkie, Alexander (referee)
This work introduces a method for optimal combination of light paths generated from the camera and from the light sources in the Photon Mapping algorithm used for computing global illumination. Our method is based on Multiple Importance Sampling, a general approach, introduced by Veach, for adaptive path connection in Bidirectional Path-Tracing. Our goal is to examine this method in connection with the biased algorithm of Photon Mapping and to improve the ineffective heuristic used in the original version of this algorithm. This heuristic is usually problematic when applied to the scenes where highly glossy materials prevail.
|
|
|
Data structures for rendering non-polygonal geometry
Kuckir, Ivan ; Křivánek, Jaroslav (advisor) ; Vorba, Jiří (referee)
In modern 3D graphics, scenes made of triangles are usually used, combined with methods based on ray tracing. Hierarchical data structures, called accelerating trees, are often used to speed up the search for intersection between ray and the scene. When testing the best current methods with non-polygonal geometry (line segments), we have found out that those structures cannot build an effective tree in many cases. The aim of this work is to formulate the problem mathematically. Thanks to this, the whole subject becomes more transparent and we can see the shortcomings of current methods, which have not yet been pointed out. At the result, we develop an algorithm which generalizes all current methods, which is not dependent on geometry and directly shows the space for improvement.
|
|
|
Real-time Global Illumination Computation
Šváb, Tomáš ; Křivánek, Jaroslav (advisor) ; Vorba, Jiří (referee)
Thesis examines the current research and development in the field of real-time global illumination. It concentrates on techniques that are capable of simulating dynamic environments and require only limited precomputation. It contains a theoretical as well as practical part. In the theoretical part the basics of rendering and selected global illumination methods are described, namely reflective shadow mapping, light propagation volumes and voxel cone tracing. The practical part includes implementation of selected methods, which are then tested, compared and improved. A program called R-GITE (Real- Time Global Illumination Testing Environment) was created to provide a foundation for prototyping these rendering algorithms. There are two main criteria in the testing - accuracy of the result and speed of computation. In the end we used the data from the tests to determine both the strong and the weak points of the methods and discuss usability of the methods for specific scenarios. Powered by TCPDF (www.tcpdf.org)
|
|
|
Realistic hair rendering in Autodesk Maya
Svoboda, Tomáš ; Křivánek, Jaroslav (advisor) ; Vorba, Jiří (referee)
This thesis describes a real-time hair rendering in 3D animation and modeling software Autodesk Maya. The renderer is part of the Stubble project a - Maya plug-in for hair modeling. The presented renderer provides a high-quality interactive preview that allows fast hair modeling without the need for rendering in slow off-line renderers. The goal of this work is to create a renderer that can generate images in real-time that are as close as possible to the output of the 3Delight renderer - a plug-in for Maya that is based on RenderMan standards.
|
|
|
Optimal strategy for connecting light paths in bidirectional methods for global ilumination computation
Vorba, Jiří
This work introduces a method for optimal combination of light paths generated from the camera and from the light sources in the Photon Mapping algorithm used for computing global illumination. Our method is based on Multiple Importance Sampling, a general approach, introduced by Veach, for adaptive path connection in Bidirectional Path-Tracing. Our goal is to examine this method in connection with the biased algorithm of Photon Mapping and to improve the ineffective heuristic used in the original version of this algorithm. This heuristic is usually problematic when applied to the scenes where highly glossy materials prevail.
|
|
|
Simulace formování obrazu v elektronovém mikroskopu pomocí sledování elektronů
Mikuš, Pavel ; Iser, Tomáš (advisor) ; Vorba, Jiří (referee)
Cryogenic electron microscopy (cryo-EM) is an evolving field allowing molecular visu- alizations with picometer resolutions. Images are acquired by shooting electrons through molecular samples and detecting the scattered electrons. From such data, 3D shapes of the molecules can be inversely reconstructed. Currently, describing and simulating the cryo-EM image formation is based either on naive transmittance models or complicated wave-function formalisms. In this thesis, we explore the possibility of simulating cryo-EM image formation via Monte Carlo electron tracing. We combine a delta-tracking algorithm with an elec- tron elastic differential cross-section function and Rutherford formulae to derive two Monte Carlo estimators. The derived models are implemented in a high-performance C++/CUDA environment and compared with other common models. Our particle-based simulated images show considerable similarity to the wave-based state-of-the-art multi- slice model. We also evaluate our models on class averages of real measurements. Both of our proposed models have significantly higher normalized cross-correlation scores with the measured class averages when compared to the most commonly used transmittance model. The thesis proves the viability of a particle-based Monte Carlo simulation of elec- tron microscope...
|
|
|
Adjoint-Driven Importance Sampling in Light Transport Simulation
Vorba, Jiří ; Křivánek, Jaroslav (advisor) ; Keller, Alexander (referee) ; Wann Jensen, Henrik (referee)
Title: Adjoint-Driven Importance Sampling in Light Transport Simulation Author: RNDr. Jiří Vorba Department: Department of Software and Computer Science Education Supervisor: doc. Ing. Jaroslav Křivánek, Ph.D., Department of Software and Computer Science Education Abstract: Monte Carlo light transport simulation has recently been adopted by the movie industry as a standard tool for producing photo realistic imagery. As the industry pushes current technologies to the very edge of their possibilities, the unprecedented complexity of rendered scenes has underlined a fundamental weakness of MC light transport simulation: slow convergence in the presence of indirect illumination. The culprit of this poor behaviour is that the sam- pling schemes used in the state-of-the-art MC transport algorithms usually do not adapt to the conditions of rendered scenes. We base our work on the ob- servation that the vast amount of samples needed by these algorithms forms an abundant source of information that can be used to derive superior sampling strategies, tailored for a given scene. In the first part of this thesis, we adapt general machine learning techniques to train directional distributions for biasing scattering directions of camera paths towards incident illumination (radiance). Our approach allows progressive...
|
guest ::
RSS feed.